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This cross-sectional herd-level study aimed to determine the occurrence of and risk factors for pathogens associated with neonatal calf diarrhea and bovine respiratory disease on Ontario dairy farms. From April to August 2022, a convenience sample of 100 dairy farms were visited once. A questionnaire covering farm biosecurity, calving and colostrum management, preweaning nutrition, and housing was administered on-farm. At each farm visit, approximately 5 calves between 2 and 35 d old were randomly selected for fecal sampling. Furthermore, approximately 5 calves between 21 to 122 d old were randomly selected for nasopharyngeal sampling. In total, 363 fecal samples (from 83 dairy farms) and 390 nasopharyngeal swab samples (from 80 dairy farms) were collected. Fecal samples were analyzed individually using a multiplex PCR to identify bacterial and parasitic enteric pathogens. Nasopharyngeal swabs were analyzed as one pooled sample per farm using bacterial culture and real-time PCR. The most common enteric pathogens detected at herd-level were Cryptosporidium parvum (67.4%) and Escherichia coli K99+ (13.2%). The most common respiratory pathogens detected at herd-level were Pasteurella multocida (62.5%), bovine coronavirus (42.5%), and Mycoplasma bovis (21.2%). Multivariable logistic models were built to explore associations between the most common pathogens and herd-level predictors selected from the questionnaire. Herd positivity for C. parvum was positively associated with having more than 61 preweaned calves per year and feeding mainly whole milk to calves. The presence of M. bovis was positively associated with herds that combined manual and automatic milk-feeding systems, and the presence of bovine coronavirus was positively associated with having more than 98 preweaned calves during the year. Univariable Poisson regression models were built to explore the association between the most common pathogens and preweaning calf mortality. Herds that were positive for C. parvum, M. bovis, or bovine coronavirus had a greater risk of preweaning calf mortality. These results provide insights for future research on pathogens associated with NCD and BRD and offer guidance for veterinarians and dairy farmers in implementing disease control measures in dairy calf herds., (© 2025, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this study was to better understand current management practices for down cows in Ontario, Canada, and to identify factors associated with the adoption of acceptable practices. An online survey was distributed to all dairy producers in Ontario, Canada (n = 3,367) and was available from November 2020 to March 2021, inclusive. Dairy producers were identified through their provincial dairy organization and contacted via email, and the survey was also promoted via social media. The survey was comprised of 134 questions, 31 of which were related to down cow management. Descriptive statistics were evaluated, and 2 logistic regression models were generated using Stata 17, exploring factors associated with 1) relocating down cows with hip lifters and 2) assisting cows to stand within an hour after discovering a down cow. A total of 226 producers responded (7.4%). Participants were predominantly male (68%), farm owners (78%), and 30-39 years old (29%). Producers reported relocating down cows with a boat or sled (32.6%), front-end loader bucket (31.4%), hip lifters (28.0%), or 'other' (with a text box to further describe) (8.0%). The median time to relocating a down cow after identifying her was 1 h (range 0 - 17h). Farms that relocated a down cow sooner after identifying her as down, were more likely to use appropriate methods to move the cow. However, we also found that farms that provided feed and water sooner to down cows, were more likely to use an inappropriate method (hip lifters) to move her. Farms that used hip lifters to move cows had higher odds of assisting a cow to stand within an hour following the discovery of recumbency. Additionally, producers who waited longer to relocate a down cow were less likely to assist the cow to stand within one hour of finding them down. Research has identified effective management practices for down cows, yet there remains a gap in understanding the implementation and the decision-making process of producers. Data from this study will be helpful in designing future research that further explores the barriers and motivations of producers when implementing evidence-based management plans to care for down dairy cows and may help inform current industry extension efforts., (© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this cross-sectional, herd-level study was to identify associations between calf management practices and herd-level preweaning mortality on Ontario dairy farms. From April to August 2022, a convenience sample of 100 dairy farms from Ontario, Canada, were visited once. A questionnaire, covering farm biosecurity, calving, colostrum management, preweaning nutrition, and housing, was verbally administered at each farm visit. Furthermore, data regarding preweaning calf mortality were retrieved from each farm's herd management software or records, including the total count of calves that survived, were culled, or died during the preweaning period for the 365 d before the farm visit. Preweaning mortality was defined as the proportion of calves that died between ≥48 h and 60 d of age divided by the total number of calves alive after 48 h of age. The herd-level preweaning mortality risk on sampled farms ranged from 0 to 15.9%, with an average of 2.8% (SD = 3.8%). A multivariable Poisson regression model was used to evaluate associations between 22 explanatory variables and preweaning mortality. Factors associated with greater herd-level preweaning mortality were larger herd size; having treatment protocols for diarrhea, pneumonia or navel infection written in collaboration with a veterinarian (compared with farms with the same treatment protocols developed without a veterinarian), and the herd-veterinarian never inquiring about calf health (compared with farms where the herd veterinarian inquired sometimes). Factors associated with lower herd-level preweaning mortality were using the calving pen for sick cows, having more than 4 people working with calves, offering calves a minimum volume of ≥9 L of milk/day, and farmers with a level of formal education higher than secondary school. These results indicate that producers may be able to reduce preweaning calf mortality by providing adequate labor for calf care, offering calves sufficient volumes of milk, being proactive in communicating with their veterinary practitioners about calf health, and potentially by engaging in continuous education., (© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Implementing biosecurity protocols is necessary to reduce the spread of disease on dairy farms. In Ontario biosecurity implementation is variable among farms, and the barriers to implementing biosecurity are unknown. Thirty-five semistructured interviews were conducted between July 2022 and January 2023 with dairy producers (n = 17) and veterinarians (n = 18). Participants also completed a demographic survey. Thematic analysis was performed with constructivist and grounded theory paradigms. Thematic coding was done inductively using NVivo software. Dairy producers' understanding of the definition of biosecurity varied, with all understanding that it was to prevent the spread of disease. Furthermore, the most common perception was that biosecurity prevented the spread of disease onto the farm. Both veterinarians and producers stated that closed herds were one of the most important biosecurity protocols. Barriers to biosecurity implementation included a lack of resources, internal and external business influencers, individual perceptions of biosecurity, and a lack of industry initiative. Understanding the barriers producers face provides veterinarians with the chance to tailor their communication to ensure barriers are reduced or for other industry members to reduce the barriers., (© 2024, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this review was to outline current implementation of biosecurity, the impact of biosecurity on the industry, and producers' and veterinarians' perceptions of biosecurity, with a focus on the Canadian dairy industry. Biosecurity has an important role in farm safety by reducing the spread of pathogens and contaminants, improving animal health and production, and maintaining human safety. Implementation of biosecurity practices varies among farms and countries. Because Canada's supply management system is different than other countries, different barriers and perceptions of biosecurity may exist. Producers may have negative perspectives on biosecurity, such as it being expensive or time consuming. Producers are motivated or deterred from biosecurity implementation for many reasons, including perceived value, disease risk, and financial incentives or deterrents. In addition, because veterinarians are a trusted source of information, their approaches to discussions on biosecurity implementation are important to understand. Veterinarians and producers appear to have differing opinions on the importance of biosecurity and approaches to discussing biosecurity. Improving biosecurity implementation requires a multifactorial approach, such as individualized education and awareness for producers, further research into efficacy of and barriers to biosecurity, and development of strategies for effective communication between veterinarians and producers., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

This closed cohort study aimed to identify the associations between dairy calf management practices and herd-level perinatal calf mortality risk. From February 2020 to June 2021, predominantly Holstein dairy farms in Québec (n = 1,832) and New Brunswick (n = 52), Canada, that were registered in the dairy herd improvement program were visited once. A questionnaire covering all aspects of precalving, calving, and colostrum management was administered. Data regarding perinatal mortality were retrieved from the dairy herd improvement program database for each farm for 2021. Perinatal mortality was calculated for each farm as the proportion of calves dead at birth or dying within 24 h after birth. A multivariable negative binomial model was used to assess herd-level factors associated with the risk of perinatal mortality. The final model included the lying surface in the calving area, the typical time to first colostrum intake, typical cow-calf contact time, the proportion of males born, the proportion of assisted calvings, and herd size. Herd-level perinatal mortality risk ranged from 0% to 38.1% (mean ± SE = 7.6% ± 0.1%). A greater proportion of males born, a higher proportion of assisted calvings, and delayed colostrum feeding were associated with increased herd-level perinatal mortality. Factors associated with a decreased herd-level perinatal mortality risk were having a typical cow-calf contact time between 7 and 12 h after calving compared with reduced cow-calf contact time, soft lying surfaces in the calving area compared with concrete and mat-lying surfaces, and an increased number of calvings per year. Our results show that although some of the significant risk factors are not well understood (i.e., calving area lying surface, typical cow-calf contact time), Canadian farmers could focus on the factors under their control (i.e., time to first colostrum feeding, proportion of difficult calvings, males born, and calvings per year) to reduce the risk of perinatal mortality. Future work should focus on qualitative research to understand the dairy farmer motivations and limitations to implementing practices identified in this and other studies to reduce perinatal mortality., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

This study aimed to evaluate the effectiveness of an automated tail movement sensor device (Moocall; Bluebell, Dublin, Ireland) to predict time of calving in dairy cows. At a commercial dairy farm in southern Ontario, Moocall (MC) devices were attached with the device's strap, and an additional elastic wrap, to the tail of cows approximately 3 d before their expected calving date. The MC has 2 types of alarm, a high activity alarm in the previous hour (1HA), and a high activity alarm in the previous 2 h (2HA); these alarms were sent and registered to the MC software. The calving and close-up pens were video monitored to determine the exact time of the onset of stage II of calving (amniotic sac visible at the vulva) and the end of stage II of calving (total expulsion of the calf). A total of 49 cows were enrolled, but we excluded 13 animals from the analysis as they had 3 or more MC drops from the tail (n = 6), a swollen tail (n = 3), or the MC device was lost (n = 4); this left 36 cows. In total, the device dropped off 21 (42%) cows. The average number of alarms (1HA and 2HA) per cow before stage II of calving was 2.7 ± 2.3 (± standard error). The first alarm after fitting the device on the tail was used to determine the device's sensitivity and specificity. Depending on the interval before the onset of parturition (i.e., 2, 4, 8, 12 h) in which the alarm was triggered, sensitivity varied from 5% to 72% and specificity from 50% to 93%. The false positive rate varied between 6% and 50% depending on the interval from the alarm to the onset of parturition. The high false positive and device drop rates (despite the addition of the elastic wrap) may compromise the applicability of this sensor device in a commercial setting., (© 2024.)

Calf mortality can be used as an indicator of animal health and welfare on dairy farms. However, several challenges surround the estimation and reporting of this metric, specifically: (1) lack of records or reliable data, (2) methods of data collection, and (3) inconsistencies in calculation and definitions used. Therefore, despite its importance, the lack of consensus on a definition of calf mortality makes it difficult to compare mortality rates between dairy farms or studies. Monitoring factors associated with calf mortality is vital to create preventative strategies. Although common strategies have been set about how to raise dairy calves and manage dairy calves, discrepancies among studies evaluating factors associated with calf mortality still exist. This review summarizes research on the evaluation of calf mortality and associated risk factors, specifically, the lack of reliable data and standardization of the definition of calf mortality. In addition, current strategies to monitor and prevent calf mortality will be presented in this review., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Calves arriving to veal and dairy-beef facilities in poor condition are at risk of future health challenges and reduced growth rates, and limited knowledge is available on how time in transit affects subsequent health and growth of these animals. The objective of this randomized controlled trial was to understand the effects of transport duration on diarrhea, respiratory disease, and growth of surplus calves destined for veal production following 6, 12, or 16 h of continuous road transport. Surplus dairy calves (n = 175; 7 transport cohorts) from 5 commercial dairy farms in Ontario, Canada, were enrolled on the day of birth. These calves were clinically examined daily on the source farms until the day before transport and on a daily basis for the first 14 d at the veal farm. On the day of transport, they were randomly assigned to 6, 12, or 16 h of transport to a veal farm. A blood sample was collected between 24 and 48 h of birth to assess transfer of passive immunity status. Calves were weighed at birth, before and immediately after transport, as well as 24, 48, and 72 h after unloading. Calves were also weighed 14 and 50 d after transport. Health exams were conducted daily at the source farm, immediately before and after transport, and once daily for 14 d thereafter to evaluate clinical signs of diarrhea, respiratory disease, dehydration, and navel inflammation. Mixed effects Poisson regression models were used to evaluate variables associated with the number of days with abnormal respiratory and fecal scores, whereas mixed logistic regression models with repeated measures were built to assess the probability of a calf having abnormal respiratory scores, abnormal fecal scores, or dehydration by day after arrival to the facility. A mixed model with repeated measures was used to evaluate calf weight at each time point at which body weight was measured after transport, whereas a mixed linear regression model was used to evaluate factors associated with average daily gain (ADG) in the 50 d after transport. Calves transported for 16 h had greater incidence of abnormal fecal scores compared with 6 h in the 14 d after transport. In addition, an interaction between age and duration of transport on the number of days with abnormal respiratory scores was identified, where calves older than 7 d of age had reduced incidence of abnormal respiratory score compared with calves 2 to 6 d old, even when transported for 16 h. As for growth, age at transport was positively associated with ADG in the 50 d of observation; however, no differences were observed between transport duration groups. These findings highlight that transporting calves for a longer duration negatively affects subsequent health, and calves greater than 1 wk of age experience improved health and growth after transport compared with their younger counterparts., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Surplus dairy calves often arrive at veal and dairy-beef rearing facilities with health and blood metabolite level abnormalities, which can affect their welfare and performance, predisposing them to future health challenges. The objective of this randomized controlled trial was to investigate the effects of transport duration and age at the time of transport on blood parameters in surplus dairy calves following 6, 12, or 16 h of continuous road transportation. All surplus calves from 5 commercial dairy farms in Ontario were enrolled and examined daily before transport (n = 175). On the day of transportation, calves were weighed, blood sampled, and randomly assigned to 6, 12, or 16 h of transportation. Blood samples were then collected immediately after transportation, as well as 24, 48, and 72 h thereafter. Serum was analyzed at a provincial diagnostic laboratory for nonesterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA), creatine kinase (CK), cholesterol, and haptoglobin. In addition, blood gas and electrolyte values were also assessed at the time of sample collection. Mixed models with repeated measures were used to assess the effects of transport duration, breed, sex, transfer of passive immunity status, weight before transportation, and age at transportation on blood parameters. Immediately following transportation, NEFA and BHBA were greater for calves transported for 12 h (Δ = 0.22 mmol/L NEFA, 95% CI = 0.15 to 0.30; Δ = 0.04 mmol/L BHBA, 95% CI = 0.02 to 0.06) and 16 h (Δ = 0.35 mmol/L NEFA, 95% CI = 0.27 to 0.42; Δ = 0.10 mmol/L BHBA, 95% CI = 0.08 to 0.11) compared with calves transported for 6 h. Glucose was lower immediately following transportation in calves transported for 16 h compared with 6 h (Δ = -15.54 mg/dL, 95% CI = -21.54 to -9.54). In addition, pH and HCO 3 - were lower in calves transported for 12 (Δ = -0.09 pH, 95% CI = -0.13 to -0.05; Δ = -1.59 mmol/L HCO 3 - , 95% CI = -2.61 to -0.56) and 16 h (Δ = -0.07 pH, 95% CI = -0.12 to -0.03; Δ = -1.95 mmol/L HCO 3 - , 95% CI = -2.95 to -0.95) compared with calves transported for 6 h. Calves transported between 15 and 19 d of age had a higher concentration of cholesterol and CK (Δ = 0.27 mmol/L cholesterol; 37.18 U/L CK) compared with 2- to 6-d-old calves, and calves 12 to 14 d old had greater reduction in HCO 3 - (Δ = -0.92 mmol/L) compared with 2- to 6-d-old calves. These findings show that transporting calves for long distances results in lower glucose concentration and suboptimal energy status, and that this effect varies based on the calf's age., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

A systematic review and Bayesian sequential pair-wise meta-analyses were conducted to assess the efficacy of internal teat sealants (ITS) administered at dry-off in comparison to no treatment for preventing new intramammary infections (IMI) and clinical mastitis (CM) in dairy cattle. This work updated a previous systematic review and network meta-analysis conducted in 2019 but employed a narrowed scope and eligibility. The updated eligibility included studies that used ITS without concurrent therapy compared to a no treatment control (NTC), a study population of dairy cows or prepartum heifers, controlled trial design, and assessed one of the following outcomes: incidence of new IMI at calving or CM during the first 30 days in milk (DIM). Risk of bias was assessed through the Cochrane Risk of Bias 2.0 tool. Evidence quality was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). There were 141 potentially relevant records identified from the updated search conducted on April 29, 2021, with a publication date restriction of 2018 or later; one study passed full-text screening and was included. Of the 32 studies included in the previous review, 12 studies were relevant after applying the modified eligibility criteria, totaling 13 studies included in this review (12 addressing IMI at calving outcome, 4 addressing CM at 30 DIM outcome). Sequential meta-analysis was conducted for both outcomes in R 3.6.0. Decisions for stopping were assessed at each analysis for intervention effect or futility in finding an effect based on a priori minimum clinically relevant values (OR δ =0.5, 0.75). ITS at dry-off significantly reduced odds of new IMI at calving compared to NTC at the second meta-analysis (OR 2 =0.27, 95% CI=0.22-0.34), and onward (OR 12 =0.29, 95% CI=0.27-0.32). For CM at 30 DIM, significance was reached at the second meta-analysis (OR 2 =0.59, 95% CI=0.47-0.73), and onward (OR 3 =0.47, 95% CI=0.42-0.51). Stopping for effect occurred at the second analysis in both outcomes and OR δ s, but low-quality evidence and heterogeneity concerns were noted. A continuity-correction to include zero-event CM studies showed significance at the third meta-analysis (OR 3 =0.79, 95% CI=0.73-0.86), stopping for effect at the fourth for OR δ = 0.75 (OR 4 =0.77, 95% CI=0.72-0.83), and stopping for futility at the second for OR δ = 0.5 (OR 2 =0.94, 95% CI=0.75-1.20), but the main CM analysis was considered more appropriate due to the sensitivity analysis' very low-quality evidence assessment. Based on sequential evidence available, sufficient research currently exists for practical use, and cessation of future research until substantial changes to ITS application occur may be appropriate., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Various case descriptions and scoring systems have been used to define neonatal calf diarrhea (NCD) and diverse diarrhea-related outcomes are reported, which limits direct comparison between studies. Therefore, the objective of this scoping review was to characterize the case definitions used for NCD and describe diarrhea-related outcomes to inform future efforts towards standardization. A literature search identified articles using 3 databases (Medline, CAB Direct, Agricola), along with Google and Google Scholar. This returned 16,854 unique articles, which were then screened for eligibility by two independent reviewers, resulting in 555 being selected for data extraction. Among articles, the study populations included mostly dairy-breed calves (88%; n = 486) while the remainder evaluated beef, crossbred, or dual purpose beef/dairy calves (10%; n = 53), or did not report breed (3%; n = 16). Studies used between 1 and 8 metrics to define NCD, with 933 unique metrics extracted in total. The most common metric was fecal consistency alone (30%; n = 281), or with at least 1 other metric (26%; n = 241). To define diarrhea, fecal consistency was either described qualitatively (e.g., "profuse liquid feces"), or semi-quantitatively, for example using a scoring system that frequently included 4 levels (n = 208). Some NCD case definitions included fecal color, volume, or odor (10%; n = 98), physical exam parameters (8%; n = 79), the duration of abnormal feces (7%; n = 67), the presence of abnormal contents (e.g., blood, 7%; n = 61), farm treatment records (6%; n = 54), fecal dry matter (1%; n = 12), or another metric (4%; n = 41). One or more references were cited for the NCD case definition by 49% of studies (n = 273/555), with the most common references being Larson et al. (1977) (n = 85), and McGuirk (2008) (n = 59). In the 555 included articles, 979 unique diarrhea-related outcomes were found, most commonly a binary categorization of calves having or not having diarrhea (49%; n = 483). Other articles reported statistical outcomes calculated from fecal scores (16%; n = 159), multiple diarrhea severities (10%; n = 95), or the age calves first developed NCD (8%; n = 76). This review characterized substantial heterogeneity among NCD case definitions and diarrhea-related outcomes, which limits interpretation and comparison of studies. Future work is required to develop and validate reporting standards for NCD to optimize knowledge synthesis and support rigorous and ethical calf health research., Competing Interests: Declarations of interest None., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The primary objective of this study was to compare male and female dairy calf management practices and evaluate risk factors associated with differences in care. Secondary objectives were to understand surplus calf transportation and marketing practices and investigate incentives to motivate calf care improvements. An online survey was distributed to all dairy producers in Ontario (n = 3,367) from November 2020 to March 2021 and Atlantic Canada (n = 557) from April to June 2021. Dairy producers were identified through provincial dairy associations and contacted via e-mail and social media. Descriptive statistics were computed, and a logistic regression model was created to evaluate factors associated with using discrepant feeding practices (i.e., fed less colostrum, fed colostrum later, or fed raw, unsalable milk) for male calves compared with females. The survey had a 7.4% response rate (n = 289/3,924) and was primarily filled out by farm owners (76%). Although colostrum and milk feeding practices were similar between male and female calves, male calves received less milk while still on the dairy farm of origin compared with females. Male calves were also more likely to be fed a higher proportion of raw, unsalable milk. Female producers and those that kept their male calves beyond 10 d of age had lower odds of using poorer feeding practices for male calves. Male calves were mostly sold between 1 and 10 d (64%), primarily through direct sales to a calf-rearing facility (45%), with auctions being the next most common method (35%). A small but notable proportion of producers (18%) agreed that euthanizing male calves is a reasonable alternative when their sale price is very low; however, few producers (13%) reported that financial costs limited their male calf care. The largest proportion (43%) of producers reported that a price premium for more vigorous calves would motivate them to take better care of their male calves. Conversely, only 28% of producers reported that a price discount for calves in poor condition would be motivating. Producers placed importance on the opinion of their calf buyer, their herd veterinarian, and the Canadian Code of Practice for the Care and Handling of Dairy Cattle when considering their calf care practices, and they highly valued practices that promote calf health. Respondents to this survey reported a lower proportion of tiestall barn use and higher milk productivity compared with typical dairy herds in the region, suggesting selection bias for more progressive dairy producers. Nevertheless, our results suggest that dairy producers provide similar care between male and female calves, but some male calves experience challenges due to milk feeding and marketing practices. Feedback from calf buyers along with continued support and guidance from herd veterinarians and the Code of Practice may motivate dairy producers to improve male calf care., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this cross-sectional study was to investigate the relationship between management practices and antimicrobial use in heifer calves on Canadian dairy farms. Questionnaires on calf management practices, herd characteristics, and calf treatment records were administered on 147 dairy farms in 5 provinces during annual farm visits in a multiyear, nationwide research project (Canadian Dairy Network for Antimicrobial Stewardship and Resistance: CaDNetASR). Questions focused on the calf caregiver, calving pen, colostrum management, milk feeding, grouping, bedding management, and age when male calves were sold. Antimicrobial treatment records were collected on each farm from either an electronic herd management system or paper-based records. Newborn heifers born in the last 12 mo were identified retrospectively and followed to 60 d of age, with antimicrobial treatments and dates of sale or death extracted for further analysis. A multivariable linear regression model was developed with the natural log of the number of antimicrobial treatments per calf-year as the dependent variable, and categorized calf management practices and farm characteristics as the independent variables. A complete data set of records on 7,817 calves was retrieved from 74 farms based on completeness of calf records. A total of 2,310 calves were treated at least once with an antimicrobial, and 7,307 individual antimicrobial treatments were recorded. Among the reasons for antimicrobial use, respiratory disease (54%) was most common, followed by diarrhea (20%), presence of a fever (3%), and umbilical disease (2%). Florfenicol (33% of recorded treatments), penicillin (23%), and trimethoprim-sulfamethoxazole (18%) were commonly used, whereas fluoroquinolones (4%), and ceftiofur (1%) were used less commonly. Farms (31%) commonly had 0-1.0 antimicrobial treatments/calf-year (median: 2.2 treatments/calf-year; interquartile range: 0.64-6.43 treatments/calf-year). Defined daily dose (DDD) per calf-year was calculated based on the Canadian bovine standards. Among the 74 farms, florfenicol (1.35 DDD/calf-year) and macrolides (0.73 DDD/calf-year) were used most, whereas ceftiofur (0.008 DDD/calf-year) was the lowest. The final multivariable linear regression model indicated that farms that fed transition milk had fewer than half the number of antimicrobial treatments per calf-year than those who did not feed transition milk. The number of antimicrobial treatments per calf-year in preweaning calves was low on many farms, and there was low use of highly important drugs for human medicine. The effect of feeding transition milk should be investigated regarding potential effects on antimicrobial use and disease prevention., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Clinical trials are a valuable study design for evaluating interventions when it is ethical and feasible for investigators to randomly allocate study animals to intervention groups. Researchers may choose to evaluate the comparative efficacy of intervention groups for their effect on outcomes that are relevant to the specific objectives of their trial. However, the results across multiple trials on the same intervention and with the same outcome should be considered when making decisions on whether to use an intervention, because the results of a single trial are subject to sampling error and do not reflect all biological variability. The objective of this review was to provide an overview of important concepts when selecting intervention groups and outcomes within a randomized controlled trial, and when building a body of evidence for intervention efficacy across multiple trials. Empirical evidence is presented to highlight that integrating and interpreting the efficacy of an intervention across trials is hindered by a lack of replication of interventions across trials. Inconsistency in the outcomes and their measurement among trials also limits the ability to build a body of evidence for the efficacy of interventions. The development of core outcome sets for specific topic areas in dairy science, updated as necessary, may improve consistency across trials and aid in the development of a body of evidence for evidence-based decision-making., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Farmers in Canada faced higher levels of mental distress than the general public prior to the Coronavirus Disease 2019 (COVID-19) pandemic and are generally less likely than the public to seek help. However, the mental health impacts of COVID-19 on farmers in Canada remain unexplored. Our objective was to investigate mental health outcomes among farmers in Canada by gender and within the context of COVID-19. We conducted a national, online, cross-sectional survey of farmers in Canada (February-May 2021). The survey included validated scales of anxiety, depression, perceived stress, burnout (emotional exhaustion, cynicism, professional efficacy), alcohol use, resilience, and questions regarding participants' perceived changes in these outcomes during the pandemic. Data were also collected on the impact of COVID-19 specific social and economic factors on mental health, help-seeking, and sense of community belonging through the pandemic. Descriptive statistics were summarized, and Chi-square analyses and t-tests were conducted to compare survey results between genders and to data collected in our similar 2016 survey and normative population data. A total of 1167 farmers participated in the survey. Participants scored more severely across scales than scale norms and the general Canadian population during COVID-19. Scale means were consistent between the 2016 and 2021 samples. Most participants with moderate to severe scores for any outcome reported worsening symptoms since the pandemic began. Women fared significantly worse than men across measures. Over twice as many women reported seeking mental health or substance use support during the pandemic than men. Participants rated the mental health impacts of all social and economic factors related to COVID-19 examined significantly ( p < 0.05) differently than the Canadian public. The pandemic has negatively impacted the mental health of farmers in Canada and in ways that differ from the general population. National level and gender-specific mental health supports are needed to help improve the mental health of farmers in Canada.

The objectives of this study were (1) to describe navel healing in male and female neonatal Holstein calves over a 14-d observation period, and (2) to determine the associations of dam parity, calving factors, and calf factors with navel measurements and time to healing. A total of 68 Holstein calves (43 female and 25 male) were enrolled. Navel healing outcomes (cessation of navel discharge, navel cord remnant drying, navel cord remnant drop-off) and navel stump measurement outcomes (proximal diameter, distal diameter, length) were recorded every 24 ± 1 h for a 14-d observation period. Data were also collected for dam parity, calving factors (time of birth, calving ease), and calf factors (calf sex, calf vitality at birth, birth weight, average daily gain, serum total protein, and medical treatment or treatments). The mean time to navel cord remnant drying was 2 d, and all calves had dry navels by d 5. A total of 56% of calves retained their navel cord remnant beyond the end of the observation period, and calves began to shed their navel cord remnants as early as d 2. In addition, at least once during the observation period, 85% of calves had a proximal navel diameter measurement over a 13-mm threshold recently proposed to identify navel infections. For distal navel diameter measurements, 72% of calves had a diameter over the 13-mm threshold at least once during the observation period. No associations were identified between navel healing outcomes and dam, calving, and calf factors. Navel measurement outcomes were associated with calving and calf factors. Specifically, proximal navel stump diameter was associated with the day of observation (decreased from d 5 to 14), calf sex (smaller in female calves), time of birth (larger in calves born overnight or unobserved, compared with the morning), and birth weight (larger in birth weights >44.1 kg compared with <38.5 kg). Distal navel stump diameter was associated with calf sex, medical treatment, and day of observation; however, we observed an interaction between sex and day of observation (larger in male calves on d 3 to 7, d 9, and d 12, compared with female calves), and sex and medical treatment (larger in untreated male calves, no difference between treated male and female calves). Navel stump length was associated with time of birth (longer in calves born overnight or unobserved compared with any other time) and the interaction of birth weight and day of observation (longer in birth weights >44.1 kg compared with 38.6-41.5 kg on d 3, 8-10, and 13, and 41.6-44.0 kg on d 3, 5, 7-8, and 13). The wide range in time to navel cord remnant drying and drop-off suggest that these measures may not be adequate indicators of calf age on their own. More research on navel healing is required to improve our understanding of factors that influence navel measurements and time to healing, as well as how this information could be used in an objective assessment of navel health., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

This review synthesizes research findings on the pain and welfare of dairy calves undergoing disbudding procedures. We describe disbudding practices in North America as well as the use and perceptions of pain control for these procedures. Governing bodies across Canada and the United States, including each country's veterinary medical association and nationwide initiatives such as proAction and Farmers Assuring Responsible Management (FARM), recommend or require the use of a local anesthetic, a nonsteroidal anti-inflammatory drug (NSAID), and a sedative for disbudding procedures. Although the use of pain relief for disbudding has increased over the past decade or so, some in the dairy industry still do not believe that pain control for disbudding is necessary. As a painful procedure, disbudding has numerous welfare impacts on the calf both during and following the procedure that can be categorized under all 3 principles of animal welfare: natural living, biological functioning, and affective state. The use of pain control for disbudding; namely, a local anesthetic and NSAID, can improve welfare outcomes such as procedure-induced pain behavior, cortisol concentrations, mechanical nociceptive threshold, emotional states, and so on, compared with no pain control for the procedure. Although extensive research exists on pain control practices for disbudding, this review identified further gaps in knowledge and areas for future research. Mechanical nociceptive threshold can be evaluated around the disbudding wounds and is a reliable test in older calves; however, this outcome in very young calves after caustic paste disbudding has been reported to be inconclusive compared with that in older calves. As well, research evaluating xylazine sedation for disbudding has reported both potentially positive and negative results that are difficult to interpret or base suggestions on for the use of this drug. Finally, wounds caused by disbudding take a long time to heal (up to 13 wk) and have increased sensitivity for the entire healing process. Therefore, future research should aim to (1) determine accurate behavioral tests for calves under 1 wk of age undergoing disbudding to better understand their experience, (2) further attempt to understand the effects of xylazine sedation for disbudding and potential impacts of providing this medication, and (3) determine more ways to reduce the healing time and pain experienced by the calf after disbudding procedures., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this study was to determine the effect of a biologically normal plane of nutrition compared with a limited plane on the primary outcome wound healing, and one dose of nonsteroidal anti-inflammatory drug (NSAID) compared with 2 on the secondary outcomes: lying behavior, haptoglobin concentrations, and mechanical nociceptive threshold (MNT) in calves disbudded via cautery iron. Eighty female Holstein calves were enrolled at birth, individually housed, and fed via a Calf Rail system (Förster Technik). A 2 × 2 factorial design was used to assess the effect of plane of nutrition and an additional NSAID. Calves were randomly assigned to a biologically normal plane of nutrition (BN; offered up to 15 L/d) or a limited plane (LP; offered up to 6 L/d) and to receive one or 2 doses of meloxicam. All calves received a lidocaine cornual nerve block and a subcutaneous injection of meloxicam 15 min before cautery disbudding at 18 to 25 d of age, and half the calves received an additional injection of meloxicam (0.5 mg/kg) 3 d after disbudding. Tissue type present, wound diameter, and wound depth were evaluated 2 times per week for 7 to 8 wk as measures of wound healing, lying behavior was recorded beginning 1 to 2 wk before disbudding until 7 to 8 wk after as a behavioral indicator of pain, haptoglobin concentrations were measured once per day for 7 d after disbudding, and MNT was evaluated 2 times/wk for 3 wk. Survival analyses were analyzed using Cox regression models (wound healing) and continuous data were analyzed using mixed-effect linear regression models. Only 12% of horn buds were completely healed by 7 to 8 wk after disbudding and 54% had re-epithelized at this time. At any time, wounds from BN calves were more likely to have had re-epithelization occur compared with wounds from LP calves (hazard ratio: 1.93, 95% CI: 1.18-3.14). Wounds from calves that received only one dose of NSAID were more likely to have re-epithelization occur, compared with wounds from calves given 2 doses (hazard ratio: 1.87, 95% CI: 1.15-3.05). Wounds from BN calves had smaller diameters and depths over time beginning on wk 3 compared with LP calves. Wounds from calves that received an additional NSAID had larger diameters and depths over time beginning on wk 4 and 3 respectively, compared with calves that only received one dose of NSAID. Calves that received an extra NSAID tended to be less sensitive 7, 10, and 17 d after disbudding compared with calves that only received one dose and spent less time lying in the week after disbudding. Calves on the BN milk program were more active compared with LP calves with lower lying times, fewer lying bouts per day, and longer average lying bouts. Our results indicate that a BN milk feeding program for calves can result in faster healing times and more activity, and that providing an extra NSAID 3 d after disbudding appears to slow the healing process but may result in less pain experienced by the calf 1 to 2 wk after the procedure. This study is also among the first to demonstrate that after the complete removal of the horn bud, wounds can take more than 8 weeks to re-epithelize and fully heal., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this randomized clinical trial was to evaluate the effectiveness of a single application of 7% iodine tincture-based umbilical dip for preventing infection of the external umbilical structures in dairy calves. Five dairy farms in southern Ontario were visited twice weekly from September 2020 through June 2021. Female (n = 244) and male (n = 40) Holstein calves were randomly assigned at birth to receive either a 7% iodine tincture-based umbilical dip (n = 140) or no treatment (n = 144). Calves in the 7% iodine tincture umbilical dip group had the product administered once by the producer shortly after birth. For each newborn calf, the experimental group, calving difficulty, volume and timing of colostrum administration, time of birth, calving pen cleanliness, and the dam ID were recorded. Calf body weight was recorded during the first visit after birth, and a blood sample was collected for measurement of serum IgG concentration. Calves were health scored twice weekly from enrollment until approximately 30 d of age for assessment of external umbilical infection, joint inflammation, respiratory disease, and diarrhea. The primary outcome of the study was external umbilical infection, which was defined as an enlarged umbilicus with pain, heat, or a malodorous discharge. Calves were also weighed at 30 and 60 d to determine average daily gain. Serum IgG concentration and birth weight did not differ significantly between groups. Twenty-nine calves (20%) in the umbilical dip group developed an external umbilical infections, compared with 31 calves (22%) in the control group. A mixed logistic regression model, accounting for farm as a random effect, showed no effect of treatment on the incidence of an external umbilical infection. However, for every additional hour that calves received colostrum after birth, the odds of developing an external umbilical infection increased during the first month of life (odds ratio = 1.15; 95% confidence interval: 1.04-1.26). Additionally, treatment had no effect on respiratory disease, joint inflammation, diarrhea, average daily gain, or mortality, compared with the untreated control. These findings suggest that administering a single application of 7% iodine tincture dip to the umbilicus around the time of birth may not be effective for preventing external umbilical infections. Farm-level management factors, including colostrum management, appear to have more influence on risk of this disease., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this scoping review was to describe the literature on the characteristics and management practices of colostrum feeding and their associations with the level of transfer of passive immunity (TPI) in dairy calves. Observational and experimental studies were searched in 5 electronic databases and 3 conference proceedings. Two reviewers independently screened primary studies, either analytic observational or experimental studies written in English. Studies on dairy or dual-purpose calves with passive immunity analyzed by blood sampling between 1 to 9 days of age were included. All studies had to compare at least one colostrum intervention or risk factor and their association with passive immunity. Of the 3,675 initially identified studies, 256 were included in this synthesis. One hundred and ninety-five were controlled trials, 57 were cohort studies, and 4 were cross-sectional studies. The effect of colostral quantity at first feeding was investigated in 30 controlled studies including studies that were comparable to each other. The effect of colostral quality was explored in 24 controlled studies with inconsistent criteria used to define the quality. The effect of the timing of first feeding of colostrum was investigated in 21 controlled studies, where the timing of feeding ranged widely from immediately after birth to 60 h of age. Only 4 controlled studies evaluated the relationship between bacterial load in the colostrum and TPI in dairy calves. Of the 256 total studies, 222 assessed blood IgG concentration while 107 measured blood total protein concentration. We identified a gap in knowledge on the association between passive immunity in dairy calves and the bacterial load in colostrum, or the timing of harvesting colostrum from the dam. A possible quantitative synthesis could be conducted among the studies that evaluated colostral quantity at the first feeding in relation to TPI in dairy calves., Competing Interests: The authors have declared that no competing interests exist.

The objective of this scoping review was to describe and characterize the existing literature regarding umbilical health and identify gaps in knowledge. Six databases were searched for studies examining umbilical health in an intensively raised cattle population. There were 4249 articles initially identified; from these, 723 full text articles were then screened, with 150 articles included in the review. Studies were conducted in the USA ( n = 41), Brazil ( n = 24), Canada ( n = 13), UK ( n = 10), and 37 additional countries. Seventeen were classified as descriptive, 24 were clinical trials, and 109 were analytical observational studies. Umbilical outcomes evaluated in descriptive studies were infection ( n = 11), parasitic infection ( n = 5), and hernias ( n = 2). Of the clinical trials, only one examined treatment of navel infections; the remainder evaluated preventative management factors for navel health outcomes (including infections ( n = 17), myiasis ( n = 3), measurements ( n = 5), hernias ( n = 1), and edema ( n = 1)). Analytical observational studies examined risk factors for umbilical health ( n = 60) and umbilical health as a risk factor ( n = 60). Studies examining risk factors for umbilical health included navel health outcomes of infections ( n = 28; 11 of which were not further defined), hernias ( n = 8), scoring the navel sheath/flap size ( n = 16), myiasis ( n = 2), and measurements ( n = 6). Studies examining umbilical health as a risk factor defined these risk factors as infection ( n = 39; of which 13 were not further defined), hernias ( n = 8; of which 4 were not further defined), navel dipping ( n = 12), navel/sheath scores as part of conformation classification for breeding ( n = 2), measurements ( n = 3), and umbilical cord drying times ( n = 2). This review highlights the areas in need of future umbilical health research such as clinical trials evaluating the efficacy of different treatments for umbilical infection. It also emphasizes the importance for future studies to clearly define umbilical health outcomes of interest, and consider standardization of these measures, including time at risk.

The objective of this prospective cohort study was to determine the effect of an abnormal fecal consistency score on weight gain and mortality in male Holstein calves and to identify risk factors associated with the occurrence of an abnormal fecal consistency score. This study enrolled 2,616 calves entering a calf-raising facility in Ontario, Canada, between January 2018 and December 2020. Fecal consistency scores were assigned twice daily for the first 28 d following arrival, where a score of 2, indicating runny consistency, and 3, indicating watery consistency, were classified as diarrhea. Severe diarrhea was classified by a score of 3. Serum total protein was measured upon arrival and the source of the calf (i.e., whether the calf came from a drover, local farm, or auction) was recorded. Body weight measurements were also collected at arrival and at 14, 56, and 77 d after arrival. Calf mortality and disease treatment during the first 77 d were recorded. On average, calves had diarrhea for 16% (4.51 d) of the first 28 d under observation, and severe diarrhea for 7% (1.87 d) of the 28 d under observation. Using a repeated measures linear regression model, we found the proportion of days with diarrhea significantly decreased weight gain at 14, 56, and 77 d following arrival. An increased proportion of days with diarrhea increased the risk of mortality, which was determined using a Cox proportional hazards model. We also found, using 2 Cox proportional hazards models, that a higher proportion of days with an abnormal fecal score increased the hazard of antibiotic treatment. With respect to factors associated with the occurrence of abnormal fecal consistency, we found that arrival weight and the source of calves were statistically significant predictors. Specifically, for every additional kilogram of body weight at arrival, the proportion of days with diarrhea decreased by 7%. With respect to source, calves from drovers had a higher proportion of days with diarrhea compared with those sourced directly from local dairy farms. Our results highlight the substantial influence the presence of abnormal fecal consistency has on short-term weight gain, mortality risk, and morbidity risk. We also demonstrate that diarrhea occurrence can be predicted using body weight at arrival and calf source. Further research should evaluate longer-term effects of diarrhea and better understand the effect of arrival weight on neonatal calf disease risk., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Canadian dairy farmers are required to use a local anesthetic and analgesic prior to all disbudding and dehorning procedures. This study was done to investigate the opinions of Ontario dairy farmers on the use of pain control for disbudding and dehorning calves and their perspectives on the current requirements of the quality assurance program. Interviews were conducted with 29 dairy farmers across Ontario. All participants used a cautery iron to disbud or dehorn their calves and some form of pain control (i.e., NSAID and/or local anesthetic). Of the 29 producers that were interviewed, 22 (76%) were in compliance with the proAction requirements for pain control. Many participants felt positive about the use of pain control for these practices. Education from veterinarians was one of the most commonly listed resources to reduce barriers to pain control use by producers. A farmer's attitude was highly referenced as an influence on producer behaviour. Although participants had positive views of pain control use, full compliance with national quality assurance requirements for disbudding and dehorning was not met by all. Producer education through veterinarians is a potential avenue to encourage the adoption of pain control use for disbudding and dehorning practices.

Group housing of preweaning dairy calves is increasing in popularity throughout the dairy industry. However, it can be more difficult to individually monitor calves to identify disease in these group systems. Automated milk feeders (AMF) not only provide producers with the opportunity to increase the milk allowance offered to preweaning calves but they can also monitor individual feeding behaviors that could identify calves at increased risk of disease. The objective of this retrospective case-control study was to determine how feeding behaviors change in preweaning calves leading up to and during a disease bout. This study was conducted between fall 2015 and fall 2016 on 2 commercial dairy farms in Ontario, Canada. Producers' treatment records for respiratory or enteric illness were used to identify cases. Control calves were selected from calves not treated for disease and matched on the days on the AMF. Both farms housed calves in dynamic groups of 9 to 11 calves with an AMF and fed milk replacer. Differences in feeding behaviors, including milk consumption, drinking speed, rewarded visits, unrewarded visits, and total visits to the AMF per day, were analyzed by mixed models accounting for repeated measures. Data were analyzed for the 7 d before, the day of, and 7 d after treatment. A total of 28 cases and 28 control calves (n = 56) were analyzed. Calves with disease consumed significantly less milk than their healthy counterparts, beginning 5 d before disease and until 3 d after disease detection. Sick calves had fewer unrewarded visits starting 3 d before until 2 d after illness detection. Sick calves drank significantly more slowly starting 4 d before illness detection until the day after illness detection compared with healthy controls. No differences were found between cases and controls for rewarded visits. Calves on a high plane of milk nutrition significantly alter feeding behaviors before illness detection. Data from AMF on feeding behaviors may help to detect disease earlier in preweaning dairy calves., (© 2022.)

Nonambulatory dairy cattle pose a complex problem due to the challenges associated with prevention, appropriate treatment and management, and arriving at an accurate prognosis. There is a breadth of literature regarding this topic, of which there is currently no formal synthesis. The objective of this scoping review was to describe and characterize the literature investigating risk factors, sequela, preventions, treatments, and prognostic factors for nonambulatory conditions in dairy cattle, with the intent of qualitatively synthesizing knowledge of the topic and identifying gaps in the literature. A literature search was conducted in 6 databases and 2 conference proceeding archives, which returned 7,568 unique articles. Initial screening of abstracts resulted in 1,544 articles reviewed at the full-text stage, of which 379 were included for data extraction. Over 75% of the included literature was published after 1980, and the most common countries in which these studies took place were the United States (n = 72), Canada (18), Sweden (17), and Germany (17). Common eligibility criteria used for inclusion were geographic region (97) and parity (92). Of the 379 studies included in this review, 144 were randomized controlled trials and 235 were observational studies. The majority of the controlled trials assessed prevention of nonambulatory conditions (116), most commonly through supplementation of vitamin D (27) and calcium (25) or the provision of anionic salts (22). Of the 28 studies focusing on treatment of nonambulatory conditions, 26 focused on calcium administration. Becoming nonambulatory was evaluated as an outcome in 165 of the observational studies. Frequently measured risk factors for becoming nonambulatory included hematological variables, such as blood calcium (73), phosphorus (53) and magnesium (42), and other factors such as parity (35) and breed (22). Recovery from a nonambulatory condition was the outcome in 31 of the observational studies, with commonly measured prognostic indicators being calcium (9), phosphorus (9), and duration of recumbency (7). Nonambulatory disorders were measured as risk factors in 53 of the observational studies, with the most commonly assessed outcomes including disorders of the transition period (11), and death or euthanasia (11). The most common terms used to describe nonambulatory conditions were "milk fever" (199) and "parturient paresis" (147). These terms were only further defined with explicit symptomatic criteria in 193 of the 379 studies in this review. Recumbency was the most commonly used of these criteria (144), followed by inability to rise (55). Potential gaps in the literature concerning nonambulatory dairy cattle that were identified in the present review included investigation of prognostic indicators for recovery from nonambulatory conditions that are applicable on farm, treatment alternatives to calcium administration, and guidance regarding the appropriate usage of terms meant to categorize nonambulatory dairy cattle., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Transportation is a stressful event for cattle, as it may involve various handling practices, commingling, deprivation of food and water, and fluctuating temperatures. Calves are particularly susceptible to these stressors because their physiological and immune systems are still developing. There has been no formal synthesis of the scientific literature evaluating the effect of transportation on young dairy calf health and performance; the aim of this scoping review is to describe and characterize this body of work. We targeted both descriptive and analytic studies examining transport of calves, including listing how the effect of transport has been evaluated. Eight databases were searched for relevant articles with eligible studies being primary research articles investigating transportation of calves of either sex who were younger than 60 d of age or weighed less than 100 kg. Two reviewers independently screened the title and abstracts of 6,859 articles with 361 potentially relevant articles screened at full text. Of these, 46 were relevant and had data extracted. Articles reporting study location were conducted in the United States (n = 5), Australia (n = 3), Japan (n = 3), and New Zealand (n = 3). Common transport-related variables evaluated included time in transit (n = 13), distance of transportation (n = 8), vehicle-related factors (n = 8), and age at time of transportation (n = 4). Outcome measures varied greatly, including blood parameters (n = 28), health assessments (n = 20), weight (n = 17), behavioral metrics (n = 14), mortality (n = 7), feed intake following transportation (n = 4), salivary cortisol concentrations (n = 3), morbidity (n = 3), and isolation of Salmonella Dublin in fecal samples (n = 2). Outcome parameters were measured during transport or ranged from immediately after to one year following transportation. As the transport-related risk factors and outcomes measured assessed varied widely between studies, future quantitative synthesis (e.g., meta-analysis) in this area may be limited. Several knowledge gaps were identified, including methods to prepare calves for transportation, such as improving nutrition, administering medication, or transporting calves at an older age or weight. Further research could also focus on consistent and clear reporting of key items related to study conduct and analysis, as well as the development of a core outcome set for calf transport studies., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Background: Over 120 million mice and rats are used annually in research, conventionally housed in shoebox-sized cages that restrict natural behaviours (e.g. nesting and burrowing). This can reduce physical fitness, impair thermoregulation and reduce welfare (e.g. inducing abnormal stereotypic behaviours). In humans, chronic stress has biological costs, increasing disease risks and potentially shortening life. Using a pre-registered protocol ( https://atrium.lib.uoguelph.ca/xmlui/handle/10214/17955 ), this meta-analysis therefore tested the hypothesis that, compared to rodents in 'enriched' housing that better meets their needs, conventional housing increases stress-related morbidity and all-cause mortality., Results: Comprehensive searches (via Ovid, CABI, Web of Science, Proquest and SCOPUS on May 24 2020) yielded 10,094 publications. Screening for inclusion criteria (published in English, using mice or rats and providing 'enrichments' in long-term housing) yielded 214 studies (within 165 articles, using 6495 animals: 59.1% mice; 68.2% male; 31.8% isolation-housed), and data on all-cause mortality plus five experimentally induced stress-sensitive diseases: anxiety, cancer, cardiovascular disease, depression and stroke. The Systematic Review Center for Laboratory animal Experimentation (SYRCLE) tool assessed individual studies' risks of bias. Random-effects meta-analyses supported the hypothesis: conventional housing significantly exacerbated disease severity with medium to large effect sizes: cancer (SMD = 0.71, 95% CI = 0.54-0.88); cardiovascular disease (SMD = 0.72, 95% CI = 0.35-1.09); stroke (SMD = 0.87, 95% CI = 0.59-1.15); signs of anxiety (SMD = 0.91, 95% CI = 0.56-1.25); signs of depression (SMD = 1.24, 95% CI = 0.98-1.49). It also increased mortality rates (hazard ratio = 1.48, 95% CI = 1.25-1.74; relative median survival = 0.91, 95% CI = 0.89-0.94). Meta-regressions indicated that such housing effects were ubiquitous across species and sexes, but could not identify the most impactful improvements to conventional housing. Data variability (assessed via coefficient of variation) was also not increased by 'enriched' housing., Conclusions: Conventional housing appears sufficiently distressing to compromise rodent health, raising ethical concerns. Results also add to previous work to show that research rodents are typically CRAMPED (cold, rotund, abnormal, male-biased, poorly surviving, enclosed and distressed), raising questions about the validity and generalisability of the data they generate. This research was funded by NSERC, Canada., (© 2022. The Author(s).)

The objective of this case-control study was to determine if feeding behavior data collected from an automated milk feeder (AMF) could be used to predict neonatal calf diarrhea (NCD) in the days surrounding diagnosis in pre-weaned group housed dairy calves. Data were collected from two research farms in Ontario between 2017 and 2020 where calves fed using an AMF were health scored daily and feeding behavior data (milk intake (mL/d), drinking speed (mL/min), number of rewarded or unrewarded visits) was collected. Calves with NCD were pair matched to healthy controls (31 pairs) by farm, gender, and age at case diagnosis to assess for differences in feeding behavior between case and control calves. Calves were first diagnosed with NCD on day 0, and a NCD case was defined as calves with a fecal score of ≥2 for 2 consecutive days, where control calves remained healthy. Repeated measure mixed linear regression models were used to determine if there were differences between case and control calves in their daily AMF feeding behavior data in the days surrounding diagnosis of NCD (-3 to +5 days). Calves with NCD consumed less milk on day 0, day 1, day 3, day 4 and day 5 following diagnosis compared to control calves. Calves with NCD also had fewer rewarded visits to the AMF on day -1, and day 0 compared to control calves. However, while there was a NCD status x day interaction for unrewarded visits, there was only a tendency for differences between NCD and control calves on day 0. In this study, feeding behaviors were not clinically useful to make diagnosis of NCD due to insufficient diagnostic ability. However, feeding behaviors are a useful screening tool for producers to identify calves requiring further attention.

Understanding how downer cattle are managed allows for the evaluation of strengths and weaknesses in these practices, which is an important step toward improving the care these animals receive. The objective of this cross-sectional study was to analyze factors associated with the care and management of downer cattle by Canadian dairy producers. Data were obtained from the 2015 National Dairy Study, and analysis was limited to the 371 respondents completing the downer cow scenario. The scenario described a downer cow that the producer wanted to keep in their herd but must be moved, and was followed by questions addressing the cow's care and management. Using multivariable logistic regression models, associations between respondent demographics and farm characteristics, and the presence of downer cow protocols, we assessed decisions regarding euthanasia and use of behavioral prognostic indicators. Written downer cow protocols were reported by 18.2% of respondents, 67% indicated that they had a nonwritten protocol, and 14.8% reported that they did not have a protocol (either written or nonwritten). Respondents from western provinces were more likely to have a written protocol than those from Ontario. Nineteen percent of the respondents with a written or unwritten protocol reported veterinary involvement in developing their downer cow protocol, which occurred more commonly on farms with more frequent herd health visits and a good producer-veterinarian relationship. An area to move a downer cow to was present on 88% of farms, with respondents who were farm staff being less likely to report having knowledge of a designated area than respondents who were the farm owner. In addition, approximately half (45%) of respondents reported moving downer cattle with hip lifters as their most common method. Behavioral prognostic indicators chosen by respondents were associated with the respondent's geographic region, age, farm size, and education. Most notably, older respondents were more likely to use appetite, and less likely to use attitude, as a prognostic indicator compared with younger respondents. Using perceived pain as a prognostic indicator was more common among respondents from western and Atlantic provinces compared with respondents from Ontario, and more common among respondents with a college or university education. These results highlighted herd and farmer demographics that were associated with how Canadian dairy producers managed downer cattle in 2015 and could be used as a benchmark for evaluating how these management practices compare with those currently implemented., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

The objective of this study was to investigate the effects of a milk byproduct-based starter pellet, high in lactose, on feed intakes, growth, and rumen development when calves were fed either a high or low level of milk. This was done by using a 2 × 2 factorial design, with 120 Holstein heifer calves randomly assigned to 1 of 2 milk treatments and 1 of 2 feed treatments upon enrollment at birth. Calves were either assigned to a low (LM) or high (HM) level of milk replacer by an automated milk-feeding system for individually-housed calves. The LM treatment calves were offered 6 L/d (150 g/L; 1.2 L, 5×/d), whereas HM treatment calves were offered 15 L/d (150 g/L; 3 L, 5×/d) of milk replacer. Calves were also assigned to a milk byproduct- (whey) based starter feed treatment (WF), or a grain-based starter ration (95% concentrate starter pellet, 5% chopped wheat straw) feed treatment (GF). All calves were offered their treatment feed starting on d 5, with water offered ad libitum from d 0. The WF treatment calves were offered 150 g/d of the milk byproduct-based pellet until they consumed the entirety for 2 out of 3 consecutive days. At this point, WF treatment calves received 150 g of the milk byproduct-based pellet top dressed onto the grain-based ration to allow for ad libitum feed consumption until weaned, when they only received the grain-based ration postweaning (d 64-77). Calves on the GF feed treatment received only the grain-based ration. All calves were gradually weaned from d 43 to 63. By design, calves on the HM treatment consumed greater levels of milk than LM treatment calves for the majority of the days in the preweaning phase (8.9 ± 0.11 vs. 5.5 ± 0.11 L/d; SE). Calves on the GF and WF treatments consumed similar amounts of milk in the preweaning phase (7.2 ± 0.11 vs. 7.2 ± 0.11 L/d); however, there was a milk and feed treatment interaction detected for milk consumption in the weaning phase, with HM-GF calves drinking more milk than the other treatments and HM-WF calves drinking more milk than both LM-GF and LM-WF calves. The WF treatment calves had greater solid feed intake during the preweaning phase than GF treatment calves, with no feed intake differences in the weaning or postweaning phases. The WF calves drank more water in the preweaning phase than GF calves. Average daily gain was similar throughout the study between the GF and WF treatment calves. Rumen physiological measures were all similar by the end of the trial (d 77) regardless of feed or milk treatment, suggesting similar rumen development postweaning. Overall, regardless of the level of milk fed, offering the milk byproduct-based starter pellet may increase preweaning feed intake, along with water consumption. However, both feed and milk treatments had similar performance and rumen development measures by the end of the trial., (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Antimicrobials should be used prudently in farm animals to prevent the development of resistant bacteria in both humans and animals. The objective of this study was to investigate Canadian dairy producers' practices for antimicrobial use in the treatment of disease in preweaning dairy calves. In-person questionnaires were administered to 144 dairy producers across 5 provinces in Canada between July 2019 and August 2020. Almost all (96%) producers used antimicrobials to treat calves with respiratory disease, but only 27% indicated they had a written treatment protocol for respiratory disease. Most (95%) of these protocols for respiratory disease were developed with input from the herd veterinarian. Seventy-four percent of producers used antimicrobials to treat calf diarrhea, with 37% of producers having a written treatment protocol for calf diarrhea with input from the herd veterinarian. The combinations of signs adopted by the producers for antimicrobial treatment in calf respiratory disease and diarrhea were evaluated based on findings from other studies. More than half (56%) of producers who used antimicrobials for calf respiratory disease decided to use antimicrobials by evaluating multiple clinical signs. Eighty-two percent of producers who used antimicrobials for calf diarrhea made decisions based on systemic signs of disease, presence of bloody stool, no response to previous treatment, or on the recommendation from the herd veterinarian. Producers with a written treatment protocol had 3 to 7 times greater odds of using antimicrobials based on multiple signs or systemic signs of disease compared with those without a protocol. Further research may investigate other calf management practices related to decision-making by producers in using antimicrobials to improve antimicrobial stewardship on dairy farms., (© 2021.)

Many dairy farmers in North America disbud or dehorn their cattle to improve human and animal safety. The Farmers Assuring Responsible Management (FARM v. 4.0) program requires that disbudding be performed before 8 wk of age with pain-control medication. The objective of this observational cross-sectional study was to quantify disbudding and dehorning practices of Wisconsin dairy producers to target future extension programming. Responses from 217 Wisconsin dairy producers and calf raisers were collected via digital surveys distributed at extension events and through industry contacts. Of the 217 respondents, 188 performed on-farm disbudding themselves. Most respondents (61%) used caustic paste as their primary method, which was most commonly applied on the day the calf was born (53%). Hot iron was used by 32% of respondents, and surgical methods (gouge, scoop, or wire saw) were used by 6% of respondents. Hot-iron disbudding was most commonly performed at 4 to 8 wk of age (41%) and 1 to 4 wk of age (33%), whereas surgical methods were most commonly performed at 8 wk or older (73%). Pain-control medication was used by 43% of respondents. Specifically, 35% used an anti-inflammatory, and 21% used a local nerve block. Veterinary involvement in creating the disbudding protocol was associated with increased odds of using pain control. Respondents with a target weaning age of ≥10 wk had greater odds of complying with FARM disbudding requirements and were also more likely to use polled genetics. Respondents aged 18 to 34 and respondents with >60 calves were more likely to have made changes to their disbudding or dehorning protocol in the last decade. Although use of pain control was higher than in previous US studies, full adoption of pain management requires further extension efforts. Veterinarians appeared influential on adoption of pain control, and their involvement may encourage adoption of pain management. Further research should investigate how the implementation of new FARM v. 4.0 standards will change the disbudding and dehorning practices of American dairy producers., (© 2021, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Systematic reviews are a valuable tool for evaluating the efficacy of interventions and for quantifying associations. To be properly assessed, reviews must be comprehensively reported. The primary objective of this study was to evaluate the completeness of reporting of systematic reviews and meta-analyses in animal health. The secondary objective was to further characterize methods for literature searches and risk of bias assessments and to document whether the risk of bias component represented an assessment of risk of bias, study quality, or levels of evidence based on the primary studies included. The dataset comprised 91 systematic reviews or meta-analyses of interventions or exposures with at least one health outcome measured at the animal or animal byproduct level, in any companion or food animal species and published between 2014 and 2018. Two reviewers independently collected information on whether each item in the PRISMA reporting guidelines was reported, with disagreements resolved by consensus. There was considerable variability in the completeness of reporting among reviews; some items, such as eligibility criteria for inclusion, were reported in most reviews (>65 %). Other items were not consistently reported; for instance, in 60 % (54) of the reviews there was no information provided on the sample size of individual studies, populations, interventions and comparators, outcomes, or follow up period. Although 89 % (81) of systematic reviews with meta-analysis included the effect size estimate and confidence intervals, it was not possible to determine which study designs were included for 30 % (14) of reviews. Results from individual PRISMA item questions were combined to determine whether all aspects of each recommended item were reported; 71 % of items were adequately reported in less than half the systematic reviews without a meta-analysis, 35 % of the items were adequately reported in less than half the systematic reviews with a meta-analysis, and 71 % of items were adequately reported in less than half of the meta-analyses without a systematic review component. An assessment of individual study level bias was included in 64 % of the reviews, although this component included an evaluation of risk of bias (35 reviews), study quality (25 reviews), or levels of evidence based on study design (12 reviews). Reporting guidelines or clinical guidelines were inappropriately used to assess risk of bias in 9 reviews. Overall, the results of this study reveal that reporting of systematic reviews in the animal health literature is suboptimal and improvements are needed to enhance utility of these reviews., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Calfhood morbidity is an important issue on commercial dairy operations, with substantial production and welfare impacts. The objective of this observational study was to evaluate potential risk factors for morbidity, including disbudding, disbudding pain control, serum total protein (STP) concentrations, and haptoglobin concentrations in young dairy calves. A total of 140 heifer calves from a commercial dairy farm in southwestern Ontario, Canada, were enrolled at 1 to 9 d of age and followed for 1 wk. Calves were scored at enrollment for several health parameters using a scale from 0 to 3, with 0 representing normal and 3 representing severely abnormal. Calves were only included if they were considered healthy enough to participate using cut points of <3 for rectal temperature and fecal score; ≤2 for nasal discharge, ocular discharge, and cough score; and 1 for ear position, navel score, and joint score. To ensure that only calves that were considered healthy on the baseline day were included, 17 calves were excluded from analysis, resulting in a total of 123 calves. These calves were a part of a disbudding trial, with 100 disbudded using a commercial caustic paste and 23 sham disbudded with a placebo paste. The disbudding paste (commercial or sham) was applied to calves on enrollment day (baseline) with health scoring at baseline and 3 and 7 d later. The following health outcomes were analyzed: diarrhea (a fecal consistency score of ≥2), respiratory disease (a total respiratory score of ≥5), and general sickness [suffering from either diarrhea, respiratory disease, or a navel or joint infection (joint or navel score of ≥2)]. The following variables were assessed for association with the outcomes: STP, inadequate transfer of passive immunity (<5.2 g/dL STP), pain control treatment for disbudding (lidocaine nerve block alone, meloxicam alone, lidocaine nerve block and meloxicam, no pain control, sham), disbudding (disbudded or sham), and haptoglobin concentrations (taken on the baseline day, +3 d and +7 d). We did not detect any relationship between the development of a health outcome of interest (diarrhea, respiratory, or sick) and disbudding or pain control on any of the days following disbudding. However, for every 1 g/dL increase in STP concentration, calves had 0.24 and 0.33 times the odds of suffering from diarrhea or any sickness event, respectively, 3 d after disbudding. At 3 d after disbudding, for every 0.1 mg/mL increase in haptoglobin concentration on that day, calves had 1.34 and 1.20 times the odds of having diarrhea or a general sickness, respectively. These findings suggest that disbudding itself or the pain control method does not appear to influence health after the procedure when healthy calves are disbudded. Calves developing an illness 3 d after disbudding were more likely to have had lower STP concentrations and increased haptoglobin concentrations., (© 2021.)

The objective of this scoping review was to characterize all available literature on modifiable management practices used during the dry period that have been evaluated for their effects on udder health in dairy cattle during the dry period and the subsequent lactation. Five databases and two conference proceedings were searched for relevant literature. Articles published in or after 1990 were eligible for inclusion. Eligible interventions or exposures were restricted to modifiable management practices; however, antimicrobial and teat sealant products were enumerated but not further characterized, as systematic reviews have been published on this topic. Other modifiable management practices were reported in 229 articles. Nutrition (n = 79), which included ration formulation and delivery (n = 44) and vitamin and mineral additives (n = 35), was the most commonly reported practice, followed by vaccines (n = 40) and modification of dry period length (n = 27). Risk of clinical mastitis (CM) was the most commonly reported outcome (n = 151); however, reporting of outcome risk periods varied widely between articles. Cure of existing intramammary infections (IMI) over the dry period (n = 40) and prevention of new IMI over the dry period (n = 54) were most commonly reported with a risk period between calving and 30 d in milk. Future systematic reviews with meta-analyses could target management practices such as nutrition, vaccines, and dry period length to quantify their effects on improving udder health during the dry period and early lactation. However, the variation in reporting of time at risk for CM and other outcomes challenges the ability of future synthesis work to inform management decisions on the basis of efficacy to cure or prevent IMI and CM. Consensus on which core outcomes should be evaluated in mastitis research and the selection of consistent risk periods for specific outcomes in animal trials is imperative., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

The adoption of automated milk feeders and group housing of preweaning dairy calves has become more common in Canada; however, disease detection in group-housed calves remains a challenge. The aim of this cross-sectional study was to assess whether feeding behavior data collected from a single point in time could be used to aid in the detection of neonatal calf diarrhea (NCD), bovine respiratory disease (BRD), and general disease, in preweaning group-housed calves being fed via an automated milk feeder. The data used was collected in an earlier study. A total of 8 dairy farms recruited from an online survey of calf-management practices were enrolled into the study. There was a total of 523 observations with 130 events of NCD, 115 events of BRD, and 210 events of general disease. Each farm was visited once in each of the fall, winter, spring, and summer, when the calves' health was scored, and the data were collected from the automated milk feeders. Mixed linear regression models were used to identify associations between feeding behavior data (milk consumption, time spent at the feeder, drinking speed, and the number of rewarded and unrewarded visits) and the presence of NCD, BRD, or general disease (having one or more of NCD, BRD, or umbilical infection), on the day of health scoring. Generalized linear mixed models were used to analyze the percentage of milk the calf consumed from their daily milk allotment. Calves with BRD consumed 63% less of their daily allotment of milk, had 2 fewer unrewarded visits to the automated milk feeder, and drank milk 152 mL/min slower compared with calves without BRD. Calves with NCD consumed 57% less of their daily milk allotment, consumed 758 mL less per day, and drank 92 mL/min slower than calves compared with calves without NCD. Calves with general disease drank 50% less of their daily milk allowance, consumed 496 mL less per day, drank 80 mL/min slower, and had 2 fewer unrewarded visits to the automated milk feeder, when compared with calves without disease. No significant associations were found between the presence of NCD, BRD, or general disease and time spent at the feeder or number of rewarded visits. Sensitivity and specificity values for disease identification were low when evaluating the feeding behaviors individually, so parallel testing was completed. To do so, if any significant feeding behavior was below the optimal cut point for disease detection as determined using a ROC curve, the calf was considered positive for disease and the sensitivity and specificity were recalculated. Parallel testing resulted in a sensitivity of 0.82, 0.78, and 0.84, and a specificity of 0.26, 0.23, and 0.21, for BRD, NCD, and general disease, respectively. This suggests that automated milk feeders may serve as a useful preliminary tool in the detection of diseased calves. For example, producers could use feeding behavior data to identify calves requiring further inspection; however, they should not use feeding behavior data as a sole disease detection method., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Automated milk feeders (AMF) are computerized systems that provide producers with a tool that can be used to more efficiently raise dairy calves and allow for easier implementation of a high plane of nutrition during the milk feeding phase. Automated milk feeders also have the ability to track individualized behavioral data, such as milk consumption, drinking speed, and the number of rewarded and unrewarded visits to the feeder, that could potentially be used to predict disease development. The objective of this scoping review was to characterize the body of literature investigating the use of AMF data to predict morbidity and mortality in dairy calves during the preweaning stage. This review lists the parameters that have been examined for associations with disease in calves and identify discrepancies found in the literature. Five databases and relevant conference proceedings were searched. Eligible studies focused on the use of behavioral parameters measured by AMF to predict morbidity or mortality in preweaned dairy calves. Two reviewers independently screened titles and abstracts from 6,675 records identified during the literature search. After title and abstract screening, 382 studies were included and then assessed at the full-text level. Of these, 56 studies fed calves using an AMF and provided some measure of morbidity or mortality. Thirteen examined AMF parameters for associations with morbidity or mortality. The studies were completed in North America (n = 6), Europe (n = 6), and New Zealand (n = 1). The studies varied in sample size, ranging from 30 to 1,052 calves with a median of 100 calves. All 13 studies included enteric disease as an outcome and 11 studies evaluated respiratory disease. Of the studies measuring enteric disease, 8 provided disease definitions (n = 8/13, 61.2%); however, for respiratory disease, only 5 provided a disease definition (n = 5/11, 45.5%). Disease definitions and thresholds varied greatly between studies, with 10 using some form of health scoring. When evaluating feeding metrics as indicators of disease, all 13 studies investigated milk consumption and 6 and 7 studies investigated drinking speed and number of rewarded and unrewarded visits, respectively. Overall, this scoping review identified that daily milk consumption, drinking speed, and rewarded and unrewarded visits may provide insight into early disease detection in preweaned dairy calves. However, the disparity in reporting of study designs and results between included studies made comparisons challenging. In addition, to aid with the interpretation of studies, standardized disease outcomes should be used to improve the utility of this primary research., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

The use of local anesthesia and a nonsteroidal anti-inflammatory drug (NSAID) can reduce indicators of pain and inflammation and encourage self-rewarding behavior in calves following disbudding. Although the use of sedation may be recommended as a best practice for disbudding, there is little research in this area. The objective of this study was to evaluate the effects of xylazine sedation in conjunction with a local anesthetic and an NSAID in calves undergoing cautery disbudding. One hundred twenty-two group-housed female and male Holstein calves fed milk with automated feeders, aged 13 to 44 d, were enrolled over 9 replicates and randomly allocated to 1 of 2 treatments: (1) sedated: lidocaine cornual nerve block, 0.5 mg/kg meloxicam (administered subcutaneously) and 0.2 mg/kg xylazine (administered intramuscularly), or (2) nonsedated: lidocaine cornual nerve block and meloxicam. Outcomes collected consisted of feeding behavior (collected using automated milk feeders), latency to drink milk following disbudding, play behavior (induced by adding bedding), lying behavior, mechanical nociceptive threshold (MNT, measured using a pressure force algometer), struggling behavior during disbudding, length of time to administer the nerve block, length of time to disbud, and serum haptoglobin concentrations. Data were analyzed using mixed models with a fixed effect for baseline values and a random effect for trial replicate. Linear regression was used to assess continuous outcomes, logistic regression for binary outcomes, and Poisson and negative binomial models for count data with negative binomial models used if the over dispersion term was significant. There were no detected differences between the treatment groups in mean daily milk consumption in the 72-h following disbudding. Sedated calves had reduced average milk drinking speed from 0 to 24 h and 24 to 48 h following disbudding compared with nonsedated calves, but no difference was detected from 48 to 72 h. Sedated calves had reduced MNT at 0, 60, and 240 min after disbudding, but no differences were detected between groups at 24 h after disbudding. Nonsedated calves had 4.5 times the odds (95% CI: 1.5-13.2) of struggling more than twice during the disbudding procedure compared with sedated calves, and it took less time to administer a nerve block to sedated calves compared with nonsedated. At +3 h, nonsedated calves were 79 times (95% CI: 22.4 to 279.2) more likely to play compared with sedated calves, and 24 h after disbudding, sedated calves were 2 times more likely to play compared with nonsedated calves (95% CI: 0.93-4.3). The results indicate that calves sedated with xylazine for cautery disbudding responded less to painful stimuli (disbudding and MNT) both during and following the procedure and had a higher rate of play behavior 24 h following sedation compared with the nonsedated calves, but xylazine may also have a prolonged carryover effect that affects suckling behavior for 48 h following sedation., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

There is a strong need for management strategies that help reduce the incidence of disease and subsequent antimicrobial use in the veal industry. Biomarkers could serve as useful tools that allow producers to take preventative measures before clinical problems occur. The objective of this prospective cohort study was to identify biomarkers measured upon arrival associated with morbidity, mortality, and average daily gain (ADG) in grain-fed veal calves. Upon arrival at a grain-fed veal facility in Ontario, Canada, calves were weighed and health-scored using a standardized health-scoring system. Several metabolites were measured including creatine kinase (CK), cholesterol, haptoglobin, manganese, serum total protein, iron, cobalt, zinc, selenium, molybdenum, and IgG. Farm personnel treated calves according to their farm protocol and weighed them at 78 d after arrival. Performance, treatment, and mortality records from the facility were used for analysis. Multivariable Cox proportional hazard models were created to evaluate metabolic biomarkers associated with morbidity and mortality. A mixed linear regression model was created to determine biomarkers associated with ADG. A total of 992 male dairy calves were evaluated at arrival from January to December 2017. Of the calves evaluated, 74 calves (7.5%) died and 877 (88.4%) were treated for illness over the 11-wk period under observation. Higher levels of haptoglobin and molybdenum were associated with a greater hazard of morbidity, whereas higher weight upon arrival and higher levels of both CK and IgG were associated with a reduced hazard of morbidity. For mortality, higher weight upon arrival and higher levels of cholesterol and IgG were associated with a lower hazard of mortality occurring over the 78-d period of observation. Higher weight, cholesterol, copper, CK, iron, and IgG were associated with increased ADG, whereas increased zinc and haptoglobin were negatively associated with ADG. These results demonstrate that certain biomarkers could be used to identify high-risk calves when measured upon arrival at a veal facility. Future research should focus on determining the utility of these biomarkers to selectively target intervention strategies to improve ADG and reduce morbidity and mortality., (Copyright © 2021 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

A systematic review and meta-analysis were conducted to determine the overall prevalence of depression among farming populations globally, and explore any heterogeneity present. Eligible studies were primary research articles published in English, which involved the collection of data for the purpose of determining the prevalence of depression among a farming population. Four relevant databases were searched in January 2019. Potential for bias was assessed using a modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. From 7662 records, 72 articles were deemed relevant and had data extracted. Of these, 45 utilized the Center for Epidemiologic Studies-Depression Revised scale (CES-D/DR) to quantify depression, 42 of which were conducted in the United States (U.S.). As a result, meta-analyses were restricted to this geographic location. Substantial heterogeneity was seen in the initial whole-group analysis ( I 2 = 97%), and while sub-group exploration suggested a significantly higher prevalence of depression among migrant farm workers (26%, 95% CI = 21-31%) than in studies examining a non-migrant farming population (12%, 95% CI = 8-17%), substantial heterogeneity remained ( I 2 = 96%), indicating that the majority of between study variation was due to factors other than sampling error. Additionally, the majority of studies (81%) in migrant farm worker populations were published since 2010, while only 21% of studies in non-migrant farming populations were published in this timeframe. It is possible with recent efforts to de-stigmatize mental illness, participants in more recent studies may be more likely to self-report depressive symptoms. Hence, while it appears that migrant farmworker populations may have an elevated prevalence of depression, it is also apparent that little research in the U.S. has been done to evaluate depression among non-migrant farming populations in recent years. Perhaps a reporting bias may account for some of the difference between the two populations. A research gap also appears to exist in estimating the prevalence of depression among farming populations outside of the US. Assessment for bias at the study level revealed challenges in reporting of key study design elements, as well as potential for selection bias in the majority of studies.

Selective antimicrobial treatment strategies present a means to reduce antimicrobial use at the time of arrival at a veal or dairy beef operation. On-farm machine leukocyte differential cell counts (DCC) that can be acquired quickly may be useful to augment calf risk identification protocols. The objective of this study was to assess the utility of DCC taken at the time of arrival at a grain-fed veal facility and 72 h postarrival for determining morbidity risk, mortality risk, and growth during the production cycle. Data were collected between June and October 2018 from 240 calves upon arrival and from a subset of 160 calves 72 h postarrival at a commercial grain-fed veal facility in Ontario, Canada. Blood samples were evaluated using the QScout BLD test for leukocyte DCC (Advanced Animal Diagnostic, Morrisville, NC). All calves were screened using a standardized health examination, and a blood sample was collected to evaluate serum total protein and DCC. Cox proportional hazards models were constructed for both morbidity and mortality outcomes. Mixed linear regression models were constructed to evaluate average daily gain. Results from data collected at the time of arrival suggest that total protein values ≥5.2 g/dL reduced the hazard of mortality and that a rectal temperature >39.6°C was associated with an increased hazard of morbidity. Calves that were dehydrated gained less, whereas calves with an increased lymphocyte count had a higher rate of growth. Results from DCC collected 72 h postarrival suggest that lymphocyte counts between 4.8 and 5.8 × 10 9 cells/L decreased the hazard of mortality and counts >7.0 × 10 9 cells/L decreased the hazard of morbidity, whereas neutrophil counts >6.0 × 10 9 cells/L increased the hazard of mortality. This study demonstrates that machine DCC at the time of arrival and 72 h after arrival has potential for use in identifying high-risk calves that might require treatment, as part of selective antimicrobial therapy protocols, with the purpose of reducing antimicrobial use without sacrificing animal health in veal facilities., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Failed transfer of passive immunity (FTPI) in dairy calves has substantial health consequences, but there have been no recently published estimates of the prevalence of FTPI on Ontario dairy farms. The major objectives of this cross-sectional study were to determine the level of FTPI in dairy calves across the province of Ontario and to determine colostrum management practices used. A convenience sample of 109 dairy farms in Ontario were visited from June to August 2019, along with 4 auction facilities from January to February 2019. At the single visit to each dairy farm, an in-person questionnaire was administered, and all calves between 24 h and 9 d of age had a blood sample collected to determine the levels of serum total protein (STP). At the auction facility, a blood sample was collected on all calves that arrived on the day of the visit. The dairy farms were distributed throughout Ontario, and the farms milked on average 151 dairy cows. Of the 444 calves sampled on Ontario dairy farms, 46% were male, 54% were female, and the mean weight and age at sampling were 46.3 kg and 4.4 d, respectively. The mean STP of calves sampled on the dairy farm was 5.69 g/dL (standard deviation = 0.78), and 107 calves (24%) had FTPI. The likelihood of FTPI was not associated with sex (female vs. male, risk ratio = 0.89, 95% confidence interval = 0.64-1.24), age (per day, risk ratio = 1.02, 95% confidence interval = 0.94-1.11), or weight (per kg, risk ratio = 0.98, 95% confidence interval = 0.96-1.01). In contrast, at the auction facilities, 386 male dairy calves were sampled and had a mean STP of 5.79 g/dL (standard deviation = 0.83). Using a cut point of ≥5.2 g/dL, 91 calves (24%) had FTPI. From the in-person questionnaire administered on the dairy farms, it was reported that the median time to first feeding of colostrum was 2.5 h (range = 0-12 h). The farms reported providing a mean of 3.3, 2.9, and 3.4 L of colostrum from 0 to 6 h after birth, 6 to 12 h after birth, and 12 to 24 h after birth, respectively. Ninety-one farms (83%) fed colostrum from the dam of the calf as their predominant source of colostrum. The most common method used to deliver the first feeding of colostrum was a nipple bottle (89 farms, 82%). Twenty-seven farms (25%) reported managing colostrum differently for male calves, which included a different colostrum source, use of poorer quality colostrum, a smaller quantity of colostrum, a longer time from birth to feeding, and generally having a lower focus on colostrum management for male calves. The prevalence of FTPI on Ontario dairy farms appears to have decreased since previous estimates, and substantial room for improvement remains. Although no overall differences were found in FTPI between male and female calves, differential reported colostrum management by sex indicates this may be a risk for male calves on a proportion of Ontario dairy farms., (Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.)

Disbudding is a common procedure practiced in the dairy industry and is known to cause pain when performed without pain control. Dairy producers who disbud calves with caustic paste are less likely to provide pain control than those using cautery. Little research has been conducted on pain control for caustic paste disbudding and no studies have specifically examined calves under 9 d of age. The objective of this study was to evaluate the efficacy of local anesthesia and nonsteroidal anti-inflammatory drug analgesia on indicators of pain and inflammation in dairy calves disbudded using caustic paste. One hundred forty Holstein heifer calves 1 to 9 d of age were enrolled in 28 blocks and randomly allocated to 1 of 5 treatments: sham control (SH); positive control (POS); lidocaine cornual nerve block (LC); meloxicam (MEL); and lidocaine cornual nerve block plus meloxicam (LCM). We measured outcomes including serum cortisol and haptoglobin, pressure sensitivity, and lying behavior. Data were analyzed using mixed linear regression models with treatment as a fixed effect, baseline values as a covariate, and trial block as a random effect. Compared with the POS group, the LCM group had reduced serum cortisol at 15, 30, 45, and 60 min post-disbudding; cortisol values were not different between LC, LCM, and SH calves at these time points. At 60, 90, 120, and 180 min post-disbudding, LCM calves had reduced cortisol compared with LC calves, whereas, values did not differ between LCM and SH calves at these time points. At 3 to 4 d post-disbudding, the LCM group tended to have reduced haptoglobin, but no differences were found between groups at 180 min and 7 d post-disbudding. At 60, 90, and 120 min post-disbudding, LC and LCM treated calves had decreased pressure sensitivity compared with other groups. No differences were seen in pressure sensitivity between groups at 180 min, 3 to 4 or 7 d post-disbudding. No differences in lying behavior were found between treatment groups on any of the 7 d following disbudding. These findings demonstrate that the combination of a local anesthetic with a nonsteroidal anti-inflammatory drug is beneficial for reducing indicators of pain and inflammation in young calves disbudded with caustic paste., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).)

Network meta-analysis is a general approach to integrate the results of multiple studies in which multiple treatments are compared, often in a pairwise manner. In this tutorial, we illustrate the procedures for conducting a network meta-analysis for binary outcomes data in the Bayesian framework using example data. Our goal is to describe the workflow of such an analysis and to explain how to generate informative results such as ranking plots and treatment risk posterior distribution plots. The R code used to conduct a network meta-analysis in the Bayesian setting is provided at GitHub., (Copyright © 2020 Hu, O'Connor, Wang, Sargeant and Winder.)

Background: Mental health issues among farmers are identified population health concerns. While one systematic review focused on suicide in farming populations in the United States, there have been no scoping studies examining mental health in farming communities worldwide. The objectives of this scoping review were to: provide a descriptive analysis of the literature pertaining to mental health outcomes in farming populations; describe the international scope of the research; and highlight published mental health services and interventions that have been evaluated., Methods: Following Arksey and O'Malley's scoping review framework, five major health and science platforms were used to identify studies examining mental health outcomes in farming populations, worldwide. Studies that met a priori inclusion criteria that were published prior to December 31, 2017 were included in this review. Data synthesis and descriptive statistics were conducted using STATA 15® software; proportions were calculated by country., Results: The initial literature search yielded 9,906 records. After title and abstract screening, 676 articles were reviewed in-full. Of these, 341 met a priori inclusion criteria. Studies included were conducted between 1979 and 2017; the majority (265; 77.7%) were published between 2002-2017. The most frequently measured outcomes were stress (41.9%), suicide (33.1%), and depression (32.6%). Over 70% of studies that examined stress described using quantitative research methods, most predominantly, cross-sectional designs (42.7%). Approximately 64% of studies that measured suicide reported using a quantitative approach; the largest proportion of included suicide studies (33.6%) described using cohort designs. Approximately 84% of studies that measured depression described using quantitative approaches; sixty percent of these studies reported using a cross-sectional study design. Twenty included studies described a mental health service or intervention (5.9%)., Conclusions: This scoping review provides a critical overview of the literature examining mental health outcomes in farming populations worldwide. Given the importance of farming and agriculture, this review can be used to ensure future research complements existing work, avoids unnecessary overlap, and begins to tackle the less-studied mental health outcomes amongst farmers. These results can guide researchers to identified gaps in research and services, leading to a more informed approach to future work, and ultimately, a more comprehensive understanding of mental health among farmers worldwide., Competing Interests: The authors have declared that no competing interests exist.

A systematic review and network meta-analysis (NMA) were conducted to address the question, 'What is the efficacy of litter management strategies to reduce morbidity, mortality, condemnation at slaughter, or total antibiotic use in broilers?' Eligible studies were clinical trials published in English evaluating the efficacy of litter management in broilers on morbidity, condemnations at slaughter, mortality, or total antibiotic use. Multiple databases and two conference proceedings were searched for relevant literature. After relevance screening and data extraction, there were 50 trials evaluating litter type, 22 trials evaluating litter additives, 10 trials comparing fresh to re-used litter, and six trials evaluating floor type. NMAs were conducted for mortality (61 trials) and for the presence or absence of footpad lesions (15 trials). There were no differences in mortality among the litter types, floor types, or additives. For footpad lesions, peat moss appeared beneficial compared to straw, based on a small number of comparisons. In a pairwise meta-analysis, there was no association between fresh versus used litter on the risk of mortality, although there was considerable heterogeneity among studies (I2 = 66%). There was poor reporting of key design features in many studies, and analyses rarely accounted for non-independence of observations within flocks.