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Background: Intramammary infections negatively affect milk quality, animal welfare and productivity in the dairy industry. Somatic cell count (SCC) is the most used screening tool to detect subclinical mastitis caused by intramammary infections. In dairy goats, SCC is greatly influenced by non-infectious factors, which complicates the interpretation. The aim of this research paper was to determine the association between SCC, intramammary infections and non-infectious factors including parity, season, lactation stage, and milk yield in dairy goats. In this longitudinal study, 451 goats from four Norwegian dairy goat herds were sampled for bacteriology and SCC up to nine times during two lactations. Factors like parity, milk yield, and stage of lactation were retrieved from the Norwegian goat recording system., Results: The most prevalent udder pathogen findings were Staphylococcus caprae (6.8%), Staphylococcus warneri (6.3%), and Staphylococcus epidermidis (3.8%), all of which had a mild but significant impact on SCC. Staphylococcus aureus was detected in 3.6% of the udder halves and had a major effect on SCC. Parity, stage of lactation, season, and milk yield significantly influenced SCC., Conclusions: This study highlights that intramammary infections caused by Staphylococcus aureus, along with factors such as increasing parity and the seasonal effects of pasturing, significantly influence the SCC. Understanding these key contributors is essential for improving udder health management and improving milk quality in goat milk production., (© 2024. The Author(s).)

In India, where dairy production leads globally, infrared thermography (IRT) and short milking tube thermography specifically are vital for managing mastitis. Therefore, the present study focuses on thermal imaging of the udder and short milking tube (SMT) of the milking machine during the peak milking process of Sahiwal cows and Murrah buffaloes during winter, summer, rainy and autumn seasons to identify sub-clinical (SCM) and clinical mastitis (CM) cases using the Darvi DTL007 camera. The udder health was assessed using the California Mastitis Test, Somatic Cell Count (SCC) and IRT throughout the year. Log 10 SCC and thermogram analysis revealed a difference (p < 0.01) between healthy, SCM, and CM cases during different seasons in both breeds. Further results showed an increase (p < 0.01) in SMT thermograms of SCM and CM cases compared to healthy quarters in Sahiwal cows during winter, summer, rainy, and autumn were 4.26 and 7.51, 2.37 and 4.47, 2.20 and 3.64, 2.90 and 4.94 ºC, respectively and for Murrah buffaloes were 3.56 and 5.55, 2.70 and 3.81, 1.72 and 3.10, 3.14 and 4.42ºC, respectively. The highest degree of increase in milking udder skin surface temperature and SMT of SCM and CM cases compared to healthy quarters was observed during the winter and the least during the rainy season. Thus, regardless of the seasons examined in this study, SMT thermograms effectively assessed SCM and CM., (© 2024. The Author(s) under exclusive licence to International Society of Biometeorology.)

Genetic improvement of udder health in dairy cows is of high relevance as mastitis is one of the most prevalent diseases. Since it is known that the heritability of mastitis is low and direct data on mastitis cases are often not available in large numbers, auxiliary traits, such as somatic cell count (SCC) are used for the genetic evaluation of udder health. In previous studies, models to predict clinical mastitis based on mid-infrared (MIR) spectral data and a somatic cell count-derived score (SCS) were developed. Those models can provide a probability of mastitis for each cow at every test-day, which is potentially useful as an additional auxiliary trait for the genetic evaluation of udder health. Furthermore, MIR spectral data were used to estimate contents of lactoferrin, a glycoprotein positively associated with immune response. The present study aimed to estimate heritabilities (h 2 ) and genetic correlations (r a ) for clinical mastitis diagnosis (CM), SCS, MIR-predicted mastitis probability (MIRprob), MIR + SCS-predicted mastitis probability (MIRSCSprob) and lactoferrin estimates (LF). Data for this study were collected within the routine milk recording and health monitoring system of Austria from 2014 to 2021 and included records of approximately 54,000 Fleckvieh cows. Analyses were performed in two datasets, including test-day records from 5 to 150 or 5 to 305 days in milk. Prediction models were applied to obtain MIR- and SCS-based phenotypes (MIRprob, MIRSCSprob, LF). To estimate heritabilities and genetic correlations bivariate linear animal models were applied for all traits. A lactation model was used for CM, defined as a binary trait, and a test-day model for all other continuous traits. In addition to the random animal genetic effect, the fixed effects year-season of calving and parity-age at calving and the random permanent environmental effect were considered in all models. For CM the random herd-year effect, for continuous traits the random herd-test day effect and the covariate days in milk (linear and quadratic) were additionally fitted. The obtained genetic parameters were similar in both datasets. The heritability found for CM was expectedly low (h 2  = 0.02). For SCS and MIRSCSprob, heritability estimates ranged from 0.23 to 0.25, and for MIRprob and LF from 0.15 to 0.17. CM was highly correlated with SCS and MIRSCSprob (r a  = 0.85 to 0.88). Genetic correlations of CM were moderate with MIRprob (r a  = 0.26 and 0.37) during 150 and 305 days in milk, respectively and low with LF (h 2  = 0.10 and 0.11). However, basic selection index calculations indicate that the added value of the new MIR-predicted phenotypes is limited for genetic evaluation of udder health., (© 2024 The Authors. Journal of Animal Breeding and Genetics published by John Wiley & Sons Ltd.)

Background: Livestock farmers face financial losses every year because milk yield and components are severely affected by udder diseases. These udder infections attract the immune response from the host and lead to the influx of neutrophils into milk to fight infection and thus the number of somatic cell count (SCC) is increased. The SCC value of milk could be used as an important indicator in detecting clinical mastitis in dairy animals. Also, the milk yield and milk quality (e.g. fat) are negatively affected by the increased SCC. The SCC is used to estimate the somatic cell score (SCS)of the milk, which is used as an indirect measure to detect subclinical mastitis. Therefore, the purpose of this study was to investigate the presence of a significant SNP rs868996547, on the suppressor of cytokine signaling 2 gene (SOCS2) which is related to milk yield and milk quality in Awassi sheep., Methods: In this study, milk production data was obtained from 210 healthy Awassi ewes with different parties and ages. The general linear model (GLM) process analysis of variance (ANOVA) was used to determine fixed effects on milk traits. The DNA extraction was done using a blood DNA extraction kit from Qiagen. To validate the presence of SNP a customized SNP detection developed by Thermofisher Scientific was used. The presence of the SNP in the SOCS2 gene was detected with genotypes (C/T, T/T, and C/C) and T being the mutated allele and it had a significant (p < 0.015) effect on the milk yield (p < 0,015;0.091), fat (p < 0,001;0,003), fat/protein ratio (p < 0.001;0,037) and log10SCC value (p < 0,006;0,015) of Awassi ewes. However, the protein, total solid, and lactose percentages in the wild type and the mutated ewes found having no significant difference (P > 0.05)., Conclusion: Our result showed the increase in SCC or SCS of the milk significantly affected the milk yield and composition. Parity and age had significant effects on ewes' milk yield (p < 0.001). In conclusion, we investigated the presence of SOCS2 gene of Awassi ewes in the study flock and its effect on milk yield, fat, and somatic cell count, and the change in milk composition and milk yield because of SCC., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The objective of this study was to determine quarters requiring antimicrobial treatment using either a benchtop somatic cell counter or culture with gram-positive selective media and compare the outcomes in these cows to those receiving blanket dry cow therapy (BDCT) in a randomized, controlled trial. We evaluated 2 novel methods of identifying cows with intramammary infections followed by selective antimicrobial treatment at a commercial dairy farm to determine their usefulness in decreasing antibiotic usage during the dry period without significant detrimental effects on milk quality and production. Cows (n = 840) were randomly allocated to one of 3 groups (BDCT, gram-positive selective media culture-based selective dry cow therapy [C-SDCT], and somatic cell count-based SDCT [S-SDCT]) the day before dry-off, and quarter-level milk samples (QLMS) were collected. The QLMS from cows in the S-SDCT group were evaluated using the cell counter, and quarters were treated if SCC was ≥200,000 cells/mL, whereas the QLMS from cows in the C-SDCT group were cultured, and quarters were treated if the culture showed growth. All cows in the BDCT received antimicrobial therapy, and all cows received an internal teat sealant regardless of treatment group. Outcomes measured were first and second DHIA test SCC, milk production through 60 DIM, cows leaving the farm, clinical mastitis, and bacteriologic new infections in a subset of quarters. Cows in both SDCT groups had fewer antimicrobial treatments than cows in the BDCT group as was expected, and cows in the C-SDCT group had fewer treatments than those in the S-SDCT group. Cows in both SDCT groups had a higher linear score at the first DHIA test (BDCT: 1.8, S-SDCT: 2.2, C-SDCT: 2.2); however, we found no other differences between groups regarding any other outcomes measured. Although antimicrobial use was significantly reduced, farms should use caution in adopting the benchtop analyzer and the selective media described in this study as ways to identify infected cows for dry cow therapy because they may result in increased linear scores early in lactation., (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 observational study aimed to explore the association of farmer-driven selective dry cow therapy (DCT), milking routine and dry cow management practices with SCC in early-lactation cows from 21 commercial dairy herds. Milking routine practices evaluated referred to cow preparation for milking, in-lactation mastitis management, and recording. Dry cow management practices related to dry cow environment and cleaning, dry-off procedure, milk cessation strategy and calving environment. Data from 2,016 multiparous cows in 21 commercial spring-calving grazing dairy herds were available for the study. Herd owners self-reported DCT (the assignment and administration of DCT was at the discretion of the herd owners with no involvement from the research team), management practices during milking and the dry period. Cow-level last test-day SCC records in 2020 (range = 105-285 DIM) and first test-day records in 2021 (range = 5-60 DIM) were obtained from milk recording databases. Quarter-level milk sampling was carried out on all cows in late lactation of 2020 (range = 240-261 DIM) for bacterial culturing. Bacteriological results were used to define cows with IMI when ≥1 quarter sample resulted in bacterial growth and there were no contaminated samples from that cow. Mixed model analyses were used to evaluate the association of selective DCT, milking routine, and dry cow management practices with cows' first test-day log 10 SCC (logSCC) in 2021. At dry-off in 2020, 47.6% of the cows were administered an internal teat sealant alone (ITS), while 52.4% were administered an antibiotic plus an internal teat sealant (AB+ITS). The mean herd-level percentage of cows with IMI was 19.7% (range = 9.8%-39.5%); Staphylococcus aureus accounted for the majority of cow-level IMI (89.9%, 357/397). Between herds, the proportion of cows administered ITS ranged from 17.7% (14/79; in a herd with an IMI prevalence of 10.1%) to 86.8% (66/76; in a herd with an IMI prevalence of 27.6%). In total, 11.8% (105/889) and 29.8% (292/980) of cows that were administered ITS or AB+ITS had an IMI in late lactation 2020, respectively. The mean untransformed SCC at the last test day in 2020 of cows administered ITS and AB+ITS was 55,000 and 197,200 cells/mL, respectively. The statistical analysis showed a significant interaction between selective DCT and milk yield at last test-day in 2020; cows with a milk yield of 15 kg and administered ITS had a 0.1 higher (untransformed SCC of 19,000 cells/mL higher) first test-day logSCC compared with cows administered AB+ITS. Additionally, greater parity, IMI in late lactation, higher logSCC at the last test-day in 2020 and longer dry periods were associated with higher logSCC at the first test-day in 2021. The current study identified cow- and herd-level management practices that could aid dairy farmers in improving the outcome of selective DCT and decrease early lactation SCC., (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/).)

Sub-clinical mastitis exhibits a higher prevalence in dairy goats than clinical mastitis, necessitating the adoption of non-invasive diagnostic techniques such as infrared thermography (IRT) to detect this economically significant production disease in the dairy sector. Accordingly, this study aims to employ IR imaging of the udder and teat quarters of lactating crossbred goats (Alpine × Beetal and Sanen × Beetal) across various seasons, utilising IRT, to discern cases of sub-clinical (SCM) and clinical mastitis (CM). Over a year, 100-110 lactating crossbred dairy goats underwent consistent IRT screenings, followed by a comprehensive evaluation of udder health status using the California mastitis test and somatic cell count (SCC). The receiver operating characteristic (ROC) analysis was conducted to establish the cut-off values for different thermographic parameters in this study. The results revealed that the SCC increased significantly (p < 0.01) in healthy, SCM, and CM milk samples across the seasons. The analysis of ROC revealed a comparatively higher sensitivity, specificity, and accuracy for udder thermograms during SCM than CM and vice versa for teat thermograms. IRT analysis reflected a difference (p < 0.01) in the udder and teat thermograms among quarters of healthy, SCM, and CM in summer, winter, autumn, and rainy seasons. A significant increase (p < 0.01) in udder thermograms was observed for quarters affected with SCM and CM relative to healthy, with an increase of 1.89 and 2.94 °C in winter, 0.85 and 1.63 °C in summer, 0.73 and 1.41 °C in rainy, and 1.33 and 2.38 °C in autumn, respectively. Similarly, for teat thermograms it was 1.79 and 2.81 °C in winter, 0.76 and 1.41 °C in summer, 0.70 and 1.37 °C in rainy, and 1.09 and 1.93 °C in autumn, respectively. Therefore, regardless of the seasons examined in this study, IRT proves to be an effective and supportive tool for early mastitis detection in lactating crossbred dairy goats., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aimed to monitor the mammary health of 37 multiparous Murrah buffaloes through infrared thermography (IRT). Based on the California Mastitis Test (CMT) and milk somatic cell counts (SCC), buffaloes were grouped into healthy (H, n = 16), subclinical mastitis (SCM, n = 10), and clinical mastitis (CM, n = 11). Buffaloes were milked twice daily in the morning (5:00-6:00 AM) and evening (5:00-6:00 PM). Rectal temperature and respiratory rates were recorded, CMT was performed and thermal images of the mammary gland of all the buffaloes were taken before and after each milking. Milk samples were analysed after each milking for SCC, fat, Solids-Not-Fat (SNF), density, protein, lactose, salts, conductivity, and pH immediately in the laboratory from fresh milk samples. The surface temperature of the periocular region of both the eyes, muzzle, flank, and vagina were also taken. Thermal images were used to assess the surface temperature of the udder (USST), teat apex (TAT), teat barrel (TB1T), teat base (TB2T), and teat skin surface (TSST). Eye and USST showed significantly higher temperatures (p < 0.05), whereas skin surface temperatures (SST) of different body parts were non-significant in both SCM and CM animals than buffaloes in the H group. Milk SCC showed a positive correlation with conductivity (r > 0.7), salts, and pH (r < 0.6) and a negative correlation with fat, SNF, density, protein, and lactose. TAT, TB1T, TB2T, TSST, and USST were positively correlated with milk SCC. Receiver Operating Characteristic (ROC) analysis of H and SCM groups showed that USST before milking had optimum sensitivity (Se = 0.80) and specificity (Sp = 0.906) among the various skin temperatures recorded. Thermal images captured during the morning showed higher sensitivity compared to images taken in the evening. Results indicate IRT can be used to monitor the mammary health of buffaloes but using IRT in conjunction with milk SCC can help in the accurate prediction of SCM in dairy buffaloes., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Total bacterial count (TBC) and SCC are important quality parameters in goat milk. Exceeding the bulk milk TBC (BMTBC) thresholds leads to price penalties for Dutch dairy goat farmers. Controlling these milk quality parameters can be challenging, especially around kidding. First, we describe the variation and the peaks around kidding of TBC and SCC in census data on Dutch bulk milk over the last 22 yr. Second, to explore causes of these elevations, we studied the variation of TBC and SCC in individual goat milk from 3 wk before to 5 wk after kidding and their association with systemic response markers IFN-γ, calprotectin, BHB, BCS, and fecal consistency. We visited 4 Dutch dairy goat farms weekly for 10 to 16 wk around kidding. Some of the goats had been dried off; other goats were milked continuously throughout pregnancy. A total of 1,886 milk samples from 141 goats were collected for automated flow cytometric quantification of TBC and SCC measurement. IFN-γ, calprotectin, and BHB were determined twice in blood of the same goats; most samples were collected after kidding. The BCS and fecal consistency were scored visually before and after kidding. We found a strong correlation between TBC and SCC (Spearman's rho = 0.87) around kidding. Furthermore, in the third week before kidding, the average TBC (5.67 log 10 cfu/mL) and SCC (6.70 log 10 cells/mL) were significantly higher compared with the fifth week after kidding, where the average TBC decreased to 4.20 log 10 cfu/mL, and the average SCC decreased to 5.92 log 10 cells/mL. In multivariable linear regression models, farm and stage of lactation were significantly associated with TBC and SCC, but none of the systemic response markers correlated with TBC or SCC. In conclusion, TBC and SCC in dairy goats were high in late lactation and decreased shortly after parturition. For SCC, the dilution effect might have caused the decrease, but this was not plausible for TBC. Moreover, the excretion of bacteria and cells in goat milk was not associated with the selected systemic response markers that were chosen as a readout for general immunity status, intestinal health, and metabolic diseases. Therefore, we assume that the TBC increase before kidding and the decrease after parturition are caused by other systemic, possibly hormonal, processes. To reduce BMTBC and bulk milk SCC, it would be advisable to keep milk of goats with highest numbers of bacteria and cells in their milk out of the bulk milk during end lactation. Further studies are needed to investigate the effects of withholding this end-lactation milk from the bulk tank., (© 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/).)

Mastitis is one of the most serious diseases that threatens the health of dairy animals. The somatic cell count (SCC) in milk is widely used to monitor mastitis. This study aimed to reveal the diversity of microorganisms in buffalo milk with high somatic cell count (SCC ≥ 3 × 10 5 cells/mL, n = 30) and low somatic cell count (SCC ≤ 5 × 10 4 cells/mL, n = 10), and identify the dominant bacteria that cause mastitis in a local buffalo farm. We also investigated the potential method to treat bacterial mastitis. The V3-V4 region of 16 S rDNA was sequenced. Results showed that, compared to the milk with low SCC, the high SCC samples showed lower microbial diversity, but a high abundance of bacteria and operational taxonomic units (OTUs). By in vitro isolation and culture, Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae were found to be the leading pathogens, which is consistent with the 16 S rDNA sequencing data. We further isolated 3 of the main pathogens and established a pathogen detection method based on ELISA. In addition, the antibacterial effects of 10 antimicrobials and 15 Chinese herbal extracts were also investigated. Results showed that the microbial has developed tolerance to several of the antimicrobials. While the water extracts of Chinese herbal medicine such as Galla Chinensis, Coptis chinensis Franch, Terminalia chebula Retz, and Sanguisorba officinalis L can effectively inhibit the growth of main pathogens. This study provides novel insight into the microbial diversity in buffalo milk and a reference for the prevention, diagnosis, and treatment of mastitis., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Bronchoalveolar lavage (BAL) cytology results from 1 lung might not be representative of both lungs., Objectives: To determine whether the lung site sampled would influence the horse's BAL cytology profile, and if a pooled BAL sample would be superior with regard to BAL cytology diagnosis in a cohort of healthy and subclinical asthmatic warmblood horses., Animals: Fifty-nine horses in 2021 and 70 horses in 2022, the follow-up included 53 of the same in each year., Methods: A cross-sectional study with follow-up included BAL cytology samples from individual lungs and from pooled BAL samples. The BAL samples were enumerated and differential cell count were applied to categorize the horses as control or with airway inflammation (AI)., Results: Bronchoalveolar lavage mast cell count was higher in left lung compared to right lung (2021; median 1.6 [range, 0.6-3.3] vs 1.2 [0.7-1.5] P = .009, 2022; median 3.1 [2.1-4.2] vs 2.4 [1.7-3.4], P < .001) and compared to pooled samples (2022; median 2.6 [1.7-3.7], P < .001). Between year 2021 and 2022, 17 of the horses had changes in BAL cytology from control to AI or vice versa., Conclusions and Clinical Importance: Pooled BAL sample was the least reliable for detecting AI, and was not representative of the overall lung condition., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Current research aims to generate an alternative model to classical methods in the determination of subclinical mastitis at 4 levels (healthy, suspicious, subclinical, and clinical). For this purpose, multilayer perceptron (MLP) artificial neural networks (ANN) was developed as test model. 5 variables from the physical properties of milk somatic cell count (SCC), electrical conductivity (EC), pH, density, and temperature at fore milking (TFM) were included in the model in the classification of mastitis. Model performance was validated on test data (%25) and compared with the multinomial logistic regression (MNLR). MLP model has shown a satisfactory performance with an accuracy of 95.14% and - 141 of AIC score better than the control model (MNLR) of 80.27% and - 133 AIC despite using higher number of parameters (104). Since the main problem is to diagnose subclinical mastitis, which does not cause any visible symptoms, it was important to distinguish between absolute subclinical (suspicious excluded positives) and absolute healthy (suspicious included positives) ones. Therefore, optimum cut-off threshold was evaluated for these two different scenarios with only variable SCC the gold standard indicator of subclinical mastitis and results were compared in the interpretation of model performance. The results show that the 5-variable MLP model exhibits a high sensitivity of 93.22% (AUC = 0.95 for healthy ones) at low cutoff thresholds as well. New studies should provide a better understanding by evaluating economics, sustainability, animal welfare and health aspects together to determine the optimal threshold value., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest regarding the publication of this manuscript., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Test-day records (n = 723,091) collected between 2012 and 2021 from 43,015 Holstein cows at 157 farms located in northern Italy were used to study the effects of heat load on milk production and composition a posteriori. The data consisted of milk yield (kg/d), traditional gross composition traits, somatic cell score (SCS), differential somatic cell count (%), milk β-hydroxybutyrate (BHB, mmol/L), milk urea (mg/dL), and milk fatty acid composition (g/100 g of milk). Test-day records were then associated with their relative temperature-humidity indexes (THI) calculated using historical environmental data registered by weather stations. Indexes were created using either yearly or summer THI data. The yearly indexes included the average daily THI (adTHI) and the maximum daily THI (mdTHI) measured throughout the whole year, and the summer indexes focused on 3 mo only (June-August) and included the average daily summer THI (adTHIs), the maximum daily summer THI (mdTHIs), and the average daily THI of the hottest 4 h of the day (adTHI4h; 1200-1600 h). All indexes had significant effects on the majority of milk traits analyzed, with, in particular, adTHI and mdTHI being highly significant in explaining the variation of all traits. Milk yield started to decline at a higher THI compared with protein and fat content. The reduction in fat ceased in the elevated THI experienced during the summer months, as demonstrated by adTHIs, mdTHIs, and adTHI4h. The cows had a tendency for increased BHB concentration with elevated THI, suggesting a greater risk of negative energy balance in presence of heat stress. Furthermore, the concentration of the de novo fatty acids C14:0 and C16:0 was reduced in higher THI, reflecting altered mammary gland activity upon elevated heat load and stress. Milk SCS tended to increase with higher adTHIs, mdTHIs, and adTHI4h. The use of yearly indexes is recommended when investigating the effects of heat load on milk composition, whereas summer indexes are suggested when investigating traits influenced by extreme conditions, such as SCS and milk yield. With global temperatures expected to further rise in the upcoming decades, early and easy identification of cows or herds suffering from heat stress, such as through changes in milk composition, is crucial for timely intervention. Adapting measures to mitigate such effects of elevated THI on milk yield and composition is a necessity for the dairy industry to prevent detrimental impacts on dairy production., (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/).)

Mastitis, a multifactorial disease influenced by both cow and herd-level factors, results in significant losses throughout the dairy chain. We aimed to evaluate the relationship between milking frequency (MF), parity order (PO), days in milk (DIM), and milk yield (MY) on somatic cell count (SCC) and the odds of a cow having subclinical mastitis (SCM) in Brazilian Holstein and Jersey dairy cows. Our dataset consisted of 747,520 test-day records from 52,954 cows, including 49,089 Holstein cows and 3865 Jersey cows and 498 herds. The SCC was evaluated using a generalized linear mixed model, whereas SCM occurrence was evaluated using a logistic regression model. A case of SCM was defined when a cow had >200×10 3 cells/mL. Our results indicated that the SCC increases with higher PO and DIM and decreases in cows milked three times a day and those with higher MY in both breeds (>40 and >25 L/d for Holstein and Jersey, respectively). Increasing MF from two to three times a day reduced the chances of a Holstein and Jersey cow having SCM by 10 and 20 %, respectively. For Holstein and Jersey cows, those with ≥quadriparous had 3.9 times and 2.2 times higher chances, respectively, of having SCM compared to primiparous cows. Cows with >305 DIM had 2.0 times greater chances of having SCM for both, Holstein and Jersey cows, compared to cows with ≤105 DIM. Holstein cows yielding ≥40 L/d had a 75 % lower chance of having SCM compared to those yielding <20 L/d, while Jersey cows with ≥25 L/d had a 60 % lower chance compared to those yielding <15 L/d. In conclusion, higher PO and DIM pose risks, whereas a MF of three times a day and higher MY are protective factors against increases in SCC and SCM occurrence in Brazilian Holstein and Jersey cows., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, we aimed to improve current udder health genetic evaluations by addressing the limitations of monthly sampled somatic cell score (SCS) for distinguishing cows with robust innate immunity from those susceptible to chronic infections. The objectives were to (1) establish novel somatic cell traits by integrating SCS and the differential somatic cell count (DSCC), which represents the combined proportion of polymorphonuclear leukocytes and lymphocytes in somatic cells and (2) estimate genetic parameters for the new traits, including their daily heritability and genetic correlations with milk production traits and SCS, using a random regression test-day model (RRTDM). We derived 3 traits, termed ML&#95;SCS&#95;DSCC, SCS&#95;4&#95;DSCC&#95;65&#95;binary, and ML&#95;SCS&#95;DSCC&#95;binary, by using milk loss (ML) estimates at corresponding SCS and DSCC levels, thresholds established in previous studies, and a threshold established from milk loss estimates, respectively. Data consisted of test-day records collected during January 2021 through March 2022 from 265 herds in Hokkaido, Japan. From these records, we extracted records between 7 to 305 d in milk (DIM) in the first lactation to fit the RRTDM. The model included the random effect of herd-test-day, the fixed effect of year-month, fixed lactation curves nested with calving age groups, and random regressions with Legendre polynomials of order 3 for additive genetic and permanent environmental effects. The analysis was performed using Gibbs sampling with Gibbsf90+ software. The averages (ranges) of the daily heritability estimates over lactation were 0.086 (0.075-0.095) for SCS, 0.104 (0.073-0.127) for ML&#95;SCS&#95;DSCC, 0.137 (0.014-0.297) for SCS&#95;4&#95;DSCC&#95;65&#95;binary, and 0.138 (0.115-0.185) for ML&#95;SCS&#95;DSCC&#95;binary; the heritability curve for SCS&#95;4&#95;DSCC&#95;65&#95;binary was erratic. Genetic correlations within the trait decreased as the DIM interval widened, especially for those integrating DSCC, indicating that these traits should be analyzed using RRTDM rather than repeatability models. The averages (ranges) of genetic correlations with milk yield over lactation were 0.01 (-0.22 to 0.28) for SCS, -0.05 (-0.40 to 0.13) for ML&#95;SCS&#95;DSCC, -0.08 (-0.17 to 0.09) for SCS&#95;4&#95;DSCC&#95;65&#95;binary, and -0.08 (-0.22 to 0.27) for ML&#95;SCS&#95;DSCC&#95;binary. Compared with SCS, the newly defined traits exhibited slightly stronger negative genetic correlations with milk yield. Especially in late lactation stages, the genetic correlation between ML&#95;SCS&#95;DSCC and milk yield was significantly below zero, with a posterior median of -0.40. Furthermore, the new traits showed positive correlations with SCS, having estimates varying from 0.68 to 0.85 for ML&#95;SCS&#95;DSCC, 0.14 to 0.47 for SCS&#95;4&#95;DSCC&#95;65&#95;binary, and 0.61 to 0.66 for ML&#95;SCS&#95;DSCC&#95;binary, depending on DIM. Considering that ML&#95;SCS&#95;DSCC and ML&#95;SCS&#95;DSCC&#95;binary have relatively high heritability (compared with SCS) and favorable genetic correlations with milk production traits and SCS, their incorporation into breeding programs appears promising. Nevertheless, their genetic relationships with (sub)clinical mastitis require further investigation., (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 examined the effects of low frequency milking on the concentrations of antimicrobial components in goat milk. Sixteen goats were divided into two groups of eight each: milking once every 2 d three times (for six days, three times group) or five times (for 10 days, five times group). On other days, milking was performed once daily. Milk was collected, and milk yield, somatic cell count (SCC), and the concentrations of some antimicrobial proteins such as lactoferrin (LF), S100A7, IgA, and sodium ions (Na + ) in milk were measured. Milk yield significantly decreased in both the groups during the low-milking frequency period, followed by an increase above the low frequency milking period in both groups. In contrast, SCC and LF concentrations in milk increased in both groups during the low frequency milking period. The concentration of S100A7 in milk temporarily decreased after the low frequency milking period, followed by a significant increase. The S100A7 concentration during this period was higher in the five times group than in the three times group. These results indicated that low frequency milking induced a gradual decrease in milk yield and a concomitant increase in antimicrobial components, such as LF and S100A7, in milk. This increase in the antimicrobial components may be useful in preventing mastitis., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Acidogenic boluses can mitigate potential negative effects of high milk yield at dry-off on udder health. This randomized controlled trial aimed to investigate the effect of administering acidogenic boluses at dry-off on dry period intramammary infection (IMI) dynamics and on milk production parameters, somatic cell count linear score (LSCC), clinical mastitis (CM), and herd removal in the next lactation. A total of 901 cows from 3 dairy farms were randomly allocated to a control (CON, n = 458; no administration of acidogenic boluses at dry-off) or treatment group (TRT, n = 443; administration of 2 acidogenic boluses at dry-off). Quarter milk samples were collected at dry-off and after calving and submitted for bacteriological milk culture. The effects of treatment on the presence of quarter-level postpartum IMI, cure of existing IMI, and acquisition of new IMI, and on the prevalence of cow-level high LSCC (LSCC ≥4) in the first 30 days in milk (DIM) were analyzed using mixed effects logistic regression. Mixed linear regression was used to analyze cow-level milk production parameters (i.e., milk yield, fat corrected milk, fat and protein yield, and LSCC) in the first 90 DIM and until 300 DIM. For CM and herd removal, Cox proportional hazard regression models were used. In addition to treatment group, lactation group at dry-off, presence of high LSCC in the last test-day, average milk yield in the week before dry-off, presence of CM in the lactation of enrollment, and biologically relevant interactions were offered in all models. There was no evidence of a difference in IMI dynamics or in milk, fat corrected milk, protein or fat yields in the subsequent lactation between groups. The TRT group had a lower LSCC in the first 2 mo postpartum compared with the CON group (2.58 ± 0.3 vs. 2.92 ± 0.3 and 2.42 ± 0.3 vs. 2.81 ± 0.3, for first and second month postpartum). The prevalence of high LSCC in the first 30 DIM was 9.1% lower in the TRT compared with the CON group (16.3% vs. 25.5%; risk difference: -9.2; 95% confidence interval [CI]: -15.8, -2.5). Cows in the TRT group exhibited reduced hazards of CM in the subsequent lactation compared with cows in the CON group (hazard ratio: 0.75; 95% CI: 0.63, 0.89) as well as a reduced hazard of herd removal (hazard ratio: 0.82, 95% CI: 0.77, 0.88). The administration of acidogenic boluses as a component of dry-off management is a promising approach to maintain good udder health and reduce the hazard of CM and herd removal during the subsequent lactation., (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/).)

Biosecurity plays a crucial role in preventing the introduction of infectious diseases to a herd as well as the spread of diseases within or between animals and herds. In particular, biosecurity measures are crucial for maintaining animal health and reducing the need for the application of antibiotic substances for fighting the rising antibiotic resistance. The object of this cross-sectional study was to investigate the presence of biosecurity measures and their association with milk quality parameters, with a special focus on somatic cell count (SCC) - an indicator for udder health -, in small-scale mountain dairy farms. Therefore, for the very first time, the CLASSYFARM system was considered, which is a computer platform integrated into the Italian national veterinary portal, that processes a significant amount of data from various sources collected in the field or from other information systems (e.g. animal welfare, health status, biosecurity, antimicrobial use, slaughterhouse information). A total of 169 dairy farms were included in the study. Biosecurity measures, based on 15 questions required in the CLASSYFARM welfare assessment protocol, as well as information about husbandry systems, milking systems and pasture practices were gathered and combined with milk yield data, provided by the South Tyrolean dairy association. Farms only scored 44.00 points on average in a scoring system from 0.00 to 100.00 points that was be able to summarize 15 different biosecurity measures in one index. Our results show a clear negative correlation (-0.713) between the biosecurity index and somatic cell score (SCS) indicating that a higher level of biosecurity, which reflects the presence of biosecurity measures within a farm, is associated with lower SCC levels. Furthermore, we found significant correlations between SCS and milk production (-0.629), confirming that udder health is linked to higher milk production. Fat, protein, and the fat-to-protein ratio showed a positive correlation with SCS (0.281, 0.146, 0.106), likely to be caused by a concentration shift effect (dilution effect). Husbandry system, breed, milking system, and pasture practices seem to have an impact as well, but the main factor was the biosecurity score. This study highlights the importance of implementing biosecurity measures for ensuring animal health and thus productivity and quality in milk production, even in small-scale farms, which are characterized by limited structure availability and smaller herds compared to big dairy enterprises in the lowlands., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: In dairy cattle, mastitis causes high financial losses and impairs animal well-being. Genetic selection is used to breed cows with reduced mastitis susceptibility. Techniques such as milk cell flow cytometry may improve early mastitis diagnosis. In a highly standardized in vivo infection model, 36 half-sib cows were selected for divergent paternal Bos taurus chromosome 18 haplotypes (Q vs. q) and challenged with Escherichia coli for 24 h or Staphylococcus aureus for 96 h, after which the samples were analyzed at 12 h intervals. Vaginal temperature (VT) was recorded every three minutes. The objective of this study was to compare the differential milk cell count (DMCC), milk parameters (fat %, protein %, lactose %, pH) and VT between favorable (Q) and unfavorable (q) haplotype cows using Bayesian models to evaluate their potential as improved early indicators of differential susceptibility to mastitis., Results: After S. aureus challenge, compared to the Q half-sibship cows, the milk of the q cows exhibited higher PMN levels according to the DMCC (24 h, p < 0.001), a higher SCC (24 h, p < 0.01 and 36 h, p < 0.05), large cells (24 h, p < 0.05) and more dead (36 h, p < 0.001) and live cells (24 h, p < 0.01). The protein % was greater in Q milk than in q milk at 0 h (p = 0.025). In the S. aureus group, Q cows had a greater protein % (60 h, p = 0.048) and fat % (84 h, p = 0.022) than q cows. Initially, the greater VT of S. aureus-challenged q cows (0 and 12-24 h, p < 0.05) reversed to a lower VT in q cows than in Q cows (48-60 h, p < 0.05). Additionally, the following findings emphasized the validity of the model: in the S. aureus group all DMCC subpopulations (24 h-96 h, p < 0.001) and in the E. coli group nearly all DMCC subpopulations (12 h-24 h, p < 0.001) were higher in challenged quarters than in unchallenged quarters. The lactose % was lower in the milk samples of E. coli-challenged quarters than in those of S. aureus-challenged quarters (24 h, p < 0.001). Between 12 and 18 h, the VT was greater in cows challenged with E. coli than in those challenged with S. aureus (3-h interval approach, p < 0.001)., Conclusion: This in vivo infection model confirmed specific differences between Q and q cows with respect to the DMCC, milk component analysis results and VT results after S. aureus inoculation but not after E. coli challenge. However, compared with conventional milk cell analysis monitoring, e.g., the global SCC, the DMCC analysis did not provide refined phenotyping of the pathogen response., (© 2024. The Author(s).)

The Latvian local goat (LVK) breed represents the only native domestic goat breed in Latvia, but its limited population places it within the endangered category. However, the LVK breed has not yet undergone a comprehensive genetic characterization. Therefore, we completed whole genome sequencing to reveal the genetic foundation of the LVK breed while identifying genetic traits linked to the somatic cell count (SCC) levels. The study included 40 genomes of LVK goats sequenced to acquire at least 35x or 10x coverage. A Principal component analysis, a genetic distance tree, and an admixture analysis showed LVK's similarity to some European breeds, such as Finnish Landrace, Alpine, and Saanen, which aligns with the breed's history. An analysis of genome-wide heterozygosity, nucleotide diversity, and LD analysis indicated that the LVK population exhibits substantial levels of genetic diversity. LVK genome was dominated by short runs of homozygosity (ROHs, ≤ 500 kb) with a median length of 25 kb. With F ROH 2.49%, average inbreeding levels were low; however, F ROH ranged broadly from 0.13 to 12.2%. With the exception of one pure-blood breeding buck exhibiting F ROH of 9.3% and F SNP of 8.5%, animals with at least 66% LVK ancestry showed moderate or no inbreeding. Overall, this study demonstrated that the LVK goats can be differentiated from imported breeds, although the population has a complex genetic structure. We were able to identify potential genetic traits associated with SCC levels, although the kinship of the animals and the heterogenic substructure of the population might have largely influenced the association analysis. We identified 26 genetic variants associated with SCC levels, which included the potentially relevant SNP rs662053371 in the OSBPL8 gene, indicating a potential signal linked to lipid metabolism in goats. To conclude, these findings present valuable insight into the genetic structure of the LVK breed for the conservation of local genetic resources., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

There are limited data available regarding pathogens causing intramammary infections (IMI) in Jersey cows. The objectives of this study were to characterize the prevalence of IMI caused by different microorganisms in lactating Jersey cattle and evaluate the associations among microbes and somatic cell count (SCC) and persistence of IMI. This prospective, observational, longitudinal study included lactating Jersey cows (n = 753) from 4 farms within a 415 km radius of Columbia, Missouri. Quarter foremilk samples were aseptically collected monthly for 3 consecutive months. Microorganisms were identified using aerobic milk culture and MALDI-TOF mass spectrometry. A commercial laboratory measured SCC using flow cytometry. Milk culture results were used to classify single microorganism infections as persistent (same microorganism species identified at first sampling and one other sampling) or nonpersistent infection. Mixed models were built to evaluate the associations between IMI status and SCC natural logarithm (lnSCC), as well as persistence and lnSCC. Overall, staphylococci were the most commonly isolated microorganisms among the 7,370 quarter-level milk samples collected. Median prevalence (using all 3 samplings) of specific microbes varied among farms; however, Staphylococcus chromogenes was a common species found at all farms. The most common microbial species that persisted were Staph. chromogenes, Staphylococcus aureus, Staphylococcus simulans, and Streptococcus uberis. Streptococcus dysgalactiae and Staph. aureus were the IMI associated with the most inflammation based on lnSCC. The small number of herds included in this study with the large variation in herd type limits the generalizability of the data. However, results of this study seem to be similar to those of previous studies in other breeds, suggesting management factors are more important than breed-specific differences when evaluating causes of IMI and associated subclinical mastitis., (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 components of milk from beef cows remain to be elucidated. This study examined the differences in the antimicrobial components of milk between dairy and beef cows. Quarter milk was collected from both Japanese Black (beef type) and Holstein (dairy type) cows to compare the concentrations of antimicrobial components. The concentration of lingual antimicrobial peptide (LAP) was higher, whereas that of the other antimicrobial components (lactoferrin, S100A7, and S100A8) was lower in beef cows than in dairy cows. Overall, these results indicate that the differences in antimicrobial components between beef and dairy cows may be associated with the difference in the prevalence of mastitis between them.

This study aimed the efficacy of meloxicam (MX) in treating acute clinical mastitis (ACM) without systemic symptoms in Holstein cows by studying improvement in udder pain, changes in prostaglandin E 2 (PGE 2 ) and bradykinin (BK) levels in the milk, and milk yield (MY) after healing. Forty-two cows with ACM were randomly assigned to the MX treatment group (T group; n=21) and the control group (C group; n=21). At onset of illness (day 0), the T group received a 0.5 mg/kg subcutaneous (SC) injection of MX whereas the C group received 15 mL SC of saline solution as a placebo. Udder tenderness (UT) was measured, and milk samples were collected on days 0-3. There was little change in the MY of the T group before and after healing, whereas MY in the C group was significantly lower than after healing. UT on day 3 in the T group was significantly lower than that in the C group. PGE 2 levels significantly decreased from day 0 to day 3 in both groups. A significant negative correlation between PGE 2 and linear score was observed on day 1 in the T group, but not in the C group. In ACM without systemic symptoms, the administration MX may be useful for restoring MY and reducing udder pain after healing.

Prior data from our group showed that first-lactation cows under organic management in United States have a high prevalence of Staphylococcus aureus, Streptococcus spp., and Staphylococcus chromogenes intramammary infections (IMI) in early lactation. Nonetheless, the relationship between IMI, udder health, and milk production in organically reared primiparous cows remains elusive. The objectives of this observational study were to investigate the relationship between presence and persistence of IMI in the first 35 d in milk (DIM) and somatic cell count (SCC) and milk production during the first 6 mo of lactation on first-lactation organic dairy cows. The analysis included a total of 1,348 composite milk samples collected during the first 35 DIM that were submitted for milk culture and 1,674 Dairy Herd Improvement Association (DHIA) tests during the first 180 DIM from 333 heifers in 4 organic dairy farms, enrolled between February 2019 and January 2020. The association between IMI in the first 35 DIM and new high SCC (SCC > 200,000 cells/mL) and milk production during the first 6 mo of lactation was investigated using Cox proportional hazards regression and mixed linear regression, respectively. The association between IMI persistence (harboring the same microorganism as reported by the laboratory for 2 or more samples) in the first 35 DIM and number of DHIA tests with high SCC during the first 6 mo of lactation was modeled using negative binomial regression. The presence of IMI by Staph. aureus (hazard ratio [HR] [95% confidence interval {CI}]: 3.35 [2.64, 4.25]) or Streptococcus spp. (HR [95% CI]: 2.25 [2.12, 2.39]) during the first 35 DIM was associated with an increased risk of new high SCC during the first 6 mo of lactation. Milk production was reduced when Streptococcus spp. were identified in milk samples. However, there was no evidence of a difference in milk production in Staph. aureus IMI. Isolation of non-aureus staphylococci and mammaliicocci was related to a mild increase in the hazards of high SCC (HR [95% CI]: 1.34 [0.97, 1.85]) and a decrease in milk production during one or more postpartum tests. Presence of gram-negative or Streptococcus-like organisms IMI was not associated with either high SCC or milk production. Presence of Bacillus IMI was associated with a lower hazard of new high SCC (HR [95% CI]: 0.45 [0.30, 0.68]), and higher milk production during the first 180 d of lactation (overall estimate [95% CI]: 1.7 kg/d [0.3, 3.0]). The persistence of IMI in the first 35 DIM was associated with the number of tests with high SCC during the lactation for all microorganisms except for Staphylococcus chromogenes. Therefore, our results suggest that the persistence of IMI in the first 35 DIM could be an important factor to understand the association between IMI detected in early lactation and lactational SCC and milk production in organic dairy heifers. Our study described associations between IMI, udder health, and milk production in first-lactation organic dairy cows that are consistent with findings from conventional dairy farms., (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 study of new indirect methods for mastitis detection is of great relevance both at the economic level of the farm and dairies, and in terms of consumer health, and animal welfare. These methods help us to monitor the disease and speed up the decision-making process on treatment of the affected animal and the destination of the milk. The main aim of this work was to study the effect of intramammary infection and other non-infectious factors on the activity of the enzyme N-acetyl-β-D-glucosaminidase (NAGase) in milk, in order to evaluate its use as an indicator for the early diagnosis of mastitis in sheep that could be less expensive, easier to measure and a better marker of inflammation or complementary to existing methods such as somatic cell count (SCC). Seven biweekly samplings were carried out, in which NAGase activity, SCC and milk were analyzed. Glands were classified according to their sanitary status based on the results of the SCC and bacteriological analysis. Non-infectious factors such as lactation stage, parity number and milking session had a statistically significant effect on NAGase values, finding the highest NAGase values at the onset and end of the study, in infectious mastitic glands of multiparous females and at morning milking. However, among the NAGase variation factors studied, the health status of the gland was the factor that caused the highest variation in enzyme levels, with infectious mastitic glands showing higher values than healthy glands. The predictive ability of NAGase was also studied by means of several logistic regression models, with the one that included NAGase together with lactation stage and parity obtaining the best results if sensitivity is to be prioritized, or the model that included NAGase, lactation stage, parity, milking and production if specificity is to be prioritized. From the results obtained, it can be concluded that the use of NAGase as an intramammary infection detection method in sheep can be useful when non-infectious factors that cause changes in the concentration of the enzyme are also considered., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

It is desirable to obtain high levels of viable Lacticaseibacillus paracasei, a widely used food probiotic whose antibacterial activity and potential application in milk remain largely uninvestigated. Here, we isolated and purified the L. paracasei strain XLK 401 from food-grade blueberry ferments and found that it exhibited strong antibacterial activity against both gram-positive and gram-negative foodborne pathogens, including Staphylococcus aureus, Salmonella paratyphi B, Escherichia coli O157, and Shigella flexneri. Then, we applied alternating tangential flow (ATF) technology to produce viable L. paracasei XLK 401 cells and its cell-free supernatant (CFS). Compared with the conventional fed-batch method, 22 h of ATF-based processing markedly increased the number of viable cells of L. paracasei XLK 401 to 12.14 ± 0.13 log cfu/mL. Additionally, the CFS exhibited good thermal stability and pH tolerance, inhibiting biofilm formation in the abovementioned foodborne pathogens. According to liquid chromatography-mass spectrometry analysis, organic acids were the main antibacterial components of XLK 401 CFS, accounting for its inhibition activity. Moreover, the CFS of L. paracasei XLK 401 effectively inhibited the growth of multidrug-resistant gram-positive Staph. aureus and gram-negative E. coli O157 pathogens in milk, and caused a reduction in the pathogenic cell counts by 6 to 7 log cfu/mL compared with untreated control, thus considerably maintaining the safety of milk samples. For the first time to our knowledge, ATF-based technology was employed to obtain viable L. paracasei on a large scale, and its CFS could serve as a broad-spectrum biopreservative for potential application against foodborne pathogens in milk products., (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/).)

Mastitis is one of the most significant diseases in dairy cows and causes several economic losses. Somatic cell count (SCC) is often used as an indirect diagnostic tool for mastitis, especially for subclinical mastitis (SCM) where no symptoms or signs can be detected. Streptococcus agalactiae is one of the main causes of contagious mastitis, and Prototheca spp. is an alga-inducing environmental mastitis that is not always correlated with increased milk SCC. The aim of this study was to evaluate the changes in the metabolomic profile of blood in relation to subclinical intramammary infection (IMI) in dairy cows. In addition, differences resulting from the etiologic agent causing mastitis were also considered. Forty Holstein-Friesian dairy cows in mid and late lactation were enrolled in this cross-sectional design study. Based on the bacteriological examination of milk, the animals were divided into 3 groups: group CTR (control group; n = 16), group A (affected by SCM with IMI caused by Strep. agalactiae; n = 17), and group P (affected by SCM with IMI caused by Prototheca spp.; n = 7). Blood samples from the jugular vein were collected in tubes containing clot activator; the serum aliquot was stored until metabolomic analysis by 1 H-nuclear magnetic resonance spectroscopy. Statistical analysis was conducted by fitting a linear model with the group as the fixed effect and SCC as the covariate. Forty-two metabolites were identified, and among them 10 were significantly different among groups. Groups A and P showed greater levels of His and lactose and lower levels of acetate, Asn, and dimethylamine compared with group CTR. Group A showed high levels of Val, and group P showed high levels of Cit and methylguanidine, as well as lower levels of 3-hydroxybutyrate, acetone, allantoin, carnitine, citrate, and ethanol. These metabolites were related to ruminal fermentations, energy metabolism, urea synthesis and metabolism, immune and inflammatory response, and mammary gland permeability. These results suggest systemic involvement with subclinical IMI and that the metabolic profile of animals with SCM undergoes changes related to the etiological agent of mastitis., (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: Rapid and accurate diagnosis of septic peritonitis is critical for initiating appropriate medical and surgical management., Objectives: The aim of this study was to determine the diagnostic utility of the total nucleated cell count (TNCC), absolute neutrophil count, neutrophil percentage, and total protein (TP) to distinguish septic versus non-septic peritoneal effusions in dogs., Methods: Electronic medical records were retrospectively searched for peritoneal fluid samples from 2008 to 2018 and classified as septic or non-septic based on bacterial culture and/or cytology results. Receiver operator characteristic curves (ROCs) were used to describe the overall diagnostic utility of each test, with optimal cutpoints analyzed to dichotomize continuous variables. Positive and negative likelihood ratios were calculated at these cutpoints., Results: A total of 166 unique samples, including 87 septic and 79 non-septic peritoneal effusions, were included. There were no significant differences in dog sex, age, or days hospitalized between groups. Septic effusions had significantly higher TP, TNCC, absolute neutrophil count, and neutrophil percentage compared with non-septic effusions. The area under the curve of the ROC curves was TNCC (0.80), absolute neutrophil count (0.80), neutrophil percentage (0.64), and TP (0.63). For TNCC and absolute neutrophil count, optimal cutoffs were 17.13 × 10 3  cells/μL and 19.88 × 10 3  cells/μL, resulting in positive and negative likelihood ratios of 2.39 and 0.28 and 2.85 and 0.28, respectively., Conclusions: Total nucleated cell counts and absolute neutrophil counts aid in the differentiation of septic and non-septic peritoneal effusions with similar diagnostic utility but are not sufficiently sensitive or specific to use without concurrent microscopic evaluation., (© 2024 The Authors. Veterinary Clinical Pathology published by Wiley Periodicals LLC on behalf of American Society for Veterinary Clinical Pathology.)

Mediterranean area represents the main habitat of Testudo hermanni. Clinical signs of disease of these tortoises are non-specific, making the hematology results crucial in revealing underlying pathological conditions. However, accurate automated identification of blood cell populations is hampered by the presence of nucleated erythrocytes (NRBC) and thrombocytes (Thr), necessitating manual methods such as counting chambers. The aim of the study was to assess the performance of the novel automated hematology analyzer Sysmex XN-1000 V, which includes a a specific channel (WNR) for counting NRBC, in accurately identify and quantify the different blood cell populations of Testudo hermanni. Additionally, its agreement with manual counts was evaluated. Fifty heparinized blood samples were initially counted using the Neubauer improved chamber and then analysed twice with Sysmex XN-1000 V. Thirteen out of 50 samples were instrumentally counted again after 48 h to assess the inter-assay precision. All WNR scattergrams were re-analysed using an ad hoc gate panel to differentiate two populations: NRBCs (weak fluorescence signal) and WBC + Thr (high fluorescence signal). Sysmex XN-1000 V demonstrated optimal intra- and inter-assay precision for NRBCs (CV 0.98% ± 1.96; 1.31% ± 2.98) and moderate precision for WBC + Thr (CV 9.24% ± 16.61; 12.69% ± 10.35). No proportional nor constant errors were observed between the methods for both the populations. The instrumental NRBC counts were consistently slightly lower, while WBC + Thr counts were slightly higher compared to manual counts. These findings suggest that Sysmex XN-1000 V can be used for analyzing cell populations in heparinized blood of Testudo hermanni. However, specific instrumental reference intervals are suggested., Competing Interests: Declaration of competing interest Sysmex corporation supplied the automated hematology instruments and reagents used in this study. Sysmex corporation played no role in the study design nor in the collection, analysis and interpretation of data, nor in the decision to submit the manuscript for publication. None of the authors has any other financial or personal relationships that could inappropriately influence or bias the content of the paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Data from the Danish milk recording system routinely enter the Danish Cattle Database, including somatic cell counts (SCC) for individual animals. Elevated SCC can signal intramammary inflammation, suggesting subclinical mastitis. Detecting mastitis is pivotal to limit severity, prevent pathogen spread, and target treatment or culling. This study aimed to differentiate normal and abnormal SCC patterns using recorded registry data. We used registry data from 2010 to 2020 for dairy cows in herds with 11 annual milk recordings. To create consistency across herds, we used data from 13,996 unique animals and eight different herds, selected based on the amount of data available, only selecting Holstein animals and conventional herds. We fitted log10-transformed SCC to days in milk (DIM) using the Wilmink and Wood's curve functions, originally developed for milk yield over the lactation. We used Nonlinear Least Square and Nonlinear Mixed Effect models to fit the log10-transformed SCC observations to DIM at animal level. Using mean squared residuals (MSR), we found a consistently better fit using a Wood's style function. Detection of MSR outliers in the model fitting process was used to identify animals with log10(SCC) curves deviating from the expected "normal" curve for that same animal. With this study, we propose a method to identify single animals with SCC patterns that indicate abnormalities, such as mastitis, based on registry data. This method could potentially lead to a registry data-based detection of mastitis cases in larger dairy herds., 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 Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Achieving a reduction in mastitis in dairy cows is a common industry goal, but there is no recent peer-reviewed record of progress in the UK., Methods: A convenience sample of 125 herds in England and Scotland was recruited based on the quality of records in 2016, willingness to participate and representative geographical distribution. Individual cow somatic cell counts and clinical mastitis data from 2012 to 2021 were summarised annually, and temporal changes were analysed. Eighty-one herds had sufficient data for comparison between 2012 and 2021, for one or more parameters., Results: Over this period, the median incidence rate of clinical mastitis decreased from 40.0 to 21.0 cases per 100 cows per year (p < 0.001), with improvement in both lactation and dry period indicators. Lactation new infection rate calculated from individual cow somatic cell counts fell from 8.75% to 5.95% (p < 0.001), dry period new infection rate fell from 16.8% to 14.1% (p < 0.05) and proportion of cows over 200,000 cells/mL fell from 20.0% to 14.3% (p < 0.001)., Limitations: Data were necessarily from herds with good records and do not provide absolute values for the industry., Conclusion: The findings reflect good progress over a 10-year period in a cohort of well-recorded herds and align with other national datasets., (© 2023 British Veterinary Association.)

This study evaluated the economic impacts caused by mastitis in a small dairy farm with similar characteristics and production to most dairy farms in southern Brazil and investigated if climatic variations influenced mastitis occurrence in the region. A farm with, on average, 45 lactating Holstein cattle was monitored from November 2021 to October 2022, and data on mastitis cases, bulk tank milk somatic cell count, animal treatment costs, milk production, animal disposal costs, and production losses were collected. Monthly averages of temperature, relative humidity (RH), and rainfall in the region were obtained. The greatest loss was related to the drop in milk production, resulting in 63.8% of total losses, followed by animal disposal (29.5%), milk disposal (4.6%), and treating animals with mastitis (2.0%), totaling a 10.6% reduction in the annual gross income. There were negative correlations between the clinical mastitis rate and monthly RH and between subclinical mastitis and temperature; the occurrence of subclinical mastitis and average RH were positively correlated. Our findings showed that mastitis negatively impacted the economy and that climate influenced mastitis occurrence., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Bronchoalveolar lavage (BAL) is a diagnostic method for the assessment of the lower respiratory airway health status in horses. Differential cell count and sometimes also total nucleated cell count (TNCC) are routinely measured by time-consuming manual methods, while faster automated methods exist. The aims of this study were to compare: 1) the Sysmex XN-V body fluid (BF) mode with the manual techniques for TNCC and two-part differential into mononuclear and polymorphonuclear cells; 2) the Olympus VS200 slide scanner and software generated deep-learning-based algorithm with manual techniques for four-part differential cell count into alveolar macrophages, lymphocytes, neutrophils, and mast cells. The methods were compared in 69 clinical BAL samples., Results: Incorrect gating by the Sysmex BF mode was observed on many scattergrams, therefore all samples were reanalyzed with manually set gates. For the TNCC, a proportional and systematic bias with a correlation of r = 0.79 was seen when comparing the Sysmex BF mode with manual methods. For the two-part differential count, a mild constant and proportional bias and a very small mean difference with moderate limits of agreement with a correlation of r = 0.84 and 0.83 were seen when comparing the Sysmex BF mode with manual methods. The Sysmex BF mode classified significantly more samples as abnormal based on the TNCC and the two-part differential compared to the manual method. When comparing the Olympus VS200 deep-learning-based algorithm with manual methods for the four-part differential cell count, a very small bias in the regression analysis and a very small mean difference in the difference plot, as well as a correlation of r = 0.85 to 0.92 were observed for all four cell categories. The Olympus VS200 deep-learning-based algorithm also showed better precision than manual methods for the four-part differential cell count, especially with an increasing number of analyzed cells., Conclusions: The Sysmex XN-V BF mode can be used for TNCC and two-part differential count measurements after reanalyzing the samples with manually set gates. The Olympus VS200 deep-learning-based algorithm correlates well with the manual methods, while showing better precision and can be used for a four-part differential cell count., (© 2024. The Author(s).)

Milk extracellular vesicles (EV) have gained extensive attention as promising diagnostic and therapeutic tools. Pre-analytical raw milk storage at low temperatures is an ordinary and usually necessary step after sample collection. It is known that direct freezing of unprocessed whole milk contaminates the native pool of milk EV with other cell structures. However, less evidence is available regarding prolonged cooling at 4°C. The current study assessed whether pre-analytical storage of bovine raw milk for several days affected EV isolation and further analysis. To confirm the independence from the health status of the mammary gland, we analyzed milk samples stored at 4°C for 1, 2, 3, and 7 d past collection, respectively, from 2 quarters of the same cow with different somatic cell counts (SCC). Seven days of refrigeration did not change the milk EV size, concentration, or morphology. We did not detect any changes in the EV cargo regarding the amount of protein and RNA, nor in the specific EV markers TSG101, CD9, and CD81 in milk from quarters with high and low SCC. Overall, we observed fewer CD81 and CD9 markers in quarters with high SCC. Moreover, we found no reduction in the mastitis-related miRNA bta-miR-223-3p, suggesting that refrigeration for several days up to 1 wk is a possible storage option compatible with further EV analyses. The findings of this study enhance the confidence that milk EV are highly stable in the raw milk matrix., (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/).)

Objective: With the Regulation (EC) 6/2019, antibiotic drying off of the entire dairy herd is no longer permissible. Hence, it is necessary to establish selective antibiotic drying off (SDCT: Selective Dry Cow Therapy) in dairy herds. With the publication of the PraeRi study in 2020, systematic data for the implementation of SDCT on farms became available for several German states. For Rhineland-Palatinate, Saarland and Hesse this type of information is only available from individual projects. Therefore, the aim of this survey was to increase the knowledge concerning the implementation of SDCT in dairy farms located in these states., Material and Methods: An online questionnaire was sent via newsletters to farmers and was published in the regional farmers' bulletins in the described catchment area. The questionnaire inquired about the saving of antibiotics during drying off, the criteria guiding the farmer's decision (cell count from monthly dairy herd improvement data (DHI), mastitis history, microbiological examination of quarter foremilk samples, California mastitis test), use of teat sealants and the type of dry off procedure (abrupt/gradual)., Results: A total of 103 questionnaires were evaluated, making the response rate ~1% for Hesse, ~3% for Saarland, and ~5% for Rhineland-Palatinate based on the number of included farms. Approximately 29% of the farmers dried off one out of four cows, 20% half, 23% three out of four and 13% all cows without using antibiotics. Eighty-nine farm managers based their decision on the somatic cell counts of DHI. Additional criteria influencing the decision were the mastitis history, results of the California Mastitis Test, or a combination of both. In 76 farms cows were dried off abruptly. In 79 farms teat sealers were used., Conclusions: Application of SDCT is established in most of the farms that participated in the survey, even though the proportion varied between farms. Legal requirements are not the only reason farmers need to increasingly deal with SDCT; sustainability programs of the dairies rely on selective drying off as well. Herd veterinarians should be supportive in implementing these measures to achieve good udder health while reducing the use of antimicrobials to a necessary minimum., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

This research paper analyzes the stability of raw cow milk in the alcohol test and seeks to understand to know the factors that influence milk stability and the occurrence of unstable non-acid milk. Milk samples were collected from the cooling tanks of rural farmers in the state of Paraná twice in summer and twice in winter. The farms were classified according to the production system: pasture with supplementation and feedlot. The following variables were analyzed: stability in the alcohol test, titratable acidity, ionized calcium concentration (iCa), chemical composition of milk, somatic cell count and standard plate count. The results showed that milk stability was greater in winter vs. summer, when the milk contained higher iCa, and in the feedlot vs. pasture system. The Pearson Correlation between variables (ethanol stability, milk composition, iCa, cooling tank temperature, milk volume, number of milking, number of cows milked, fat/protein ratio, distance and travel time) were analyzed. Stability was negatively correlated with iCa concentration and positively with lactose content. Logistic regression of the risk of unstable non-acid milk at 72% alcohol (UNAM 72 ) showed that only iCa and lactose were determinants, while evaluation of the same risk at 78% alcohol revealed iCa, titratable acidity, lactose and milk urea nitrogen as risk factors. Under the dairy farming conditions of Paraná state, the frequency of UNAM 72 was low (12.16%) and was higher in summer and in pasture systems with supplementation. In conclusion, in dairy herds bred with high technological level, with adequate nutritional and health management, the frequency of UNAM is low and is related to nutritional management abnd, perhaps, heat stress, factors that alter iCa and lactose levels.

We investigated the antimicrobial components in cow milk at dry off and postpartum and their contribution in preventing new high SCC at quarter level. Milk samples from 72 quarters of 19 lactating cows were collected at last milking before dry off and at 7 d after parturition. Milk yield of each cow was recorded and SCC, IgG, IgA, lactoferrin, lingual antimicrobial peptide (LAP), and S100A7 concentrations in each quarter milk sample were measured. The postpartum milk yield was significantly higher than that at dry off. The IgG, IgA and lactoferrin concentrations in milk at dry off were significantly higher than those at postpartum, whereas the LAP concentration was lower. Quarters with SCC < 300 000 cells/ml at both dry off and postpartum were classified as persistent low SCC (PL) whereas those that rose above that same threshold postpartum were classified as new high SCC (NH). At dry off, IgG and LAP concentrations in milk were significantly higher in PL than in NH. These results suggest that high LAP concentrations during the dry period may contribute toward the prevention of new high SCC.

An epidemiological analysis was conducted on production records in Hokkaido, Japan, to investigate the potential association between improved milk quality and longevity outcomes. The study found significant variations in herd somatic cell count levels and chronic subclinical mastitis morbidity based on geographical area and herd size. The analysis also revealed a positive correlation between herd somatic cell count and chronic subclinical mastitis morbidity. Although the hypothesis of a causal link between milk quality and longevity was examined, no such association was found. However, intensive assistance for identified high-risk areas and farms is expected to enhance overall milk quality.

Immune responses in bovine clinical mastitis (CM) probably differ depending on the causative pathogen and disease severity. The observational study aimed to investigate whether both factors are associated with the dynamics of immune indicators, including somatic cell score (SCS), white blood cell count (WBC), serum albumin/globulin (A/G) ratio, and differential somatic cell count (DSCC). We collected blood and milk samples 0, 3, 5, 7, 14, and 21 days after CM occurred in 38 cows, and grouped the cases (n=49) by disease severity and pathogen. We analyzed data using a linear mixed model considering the effects of pathogens and severity, calculated estimated-marginal means for indicators at each time point, and compared the means between groups. The dynamics of WBC varied depending on both pathogen and severity. WBC changed drastically in either severe or coliform-caused CM, slightly elevated in streptococcal mastitis, but unchanged in staphylococcal mastitis. This possibly relates to the deficiency in innate immune response toward staphylococci. The A/G ratio also changed depending on severity, as it dropped sharply only in severe CM. We observed a non-linear relationship between DSCC and SCS, possibly due to mammary epithelial cells shedding in milk when CM occurred. When cows recovering from Streptococcus dysgalatiae mastitis, DSCC decreased while SCS remained high, suggesting a healing process requiring more macrophages. Our results demonstrate that both the severity and pathogen are associated with immune responses in CM, providing insights into mastitis pathogenesis.

In mouse embryos, inside cells are allocated in 16-cell embryos through a well-orchestrated sequence of events involving compaction and polarization. The emergence of inside cells is of great importance as itl later gives rise to the inner cell mass and epiblast. In this study, we report the sequence of critical events in embryology (compaction, inside cells allocation and fragmentation) in bovine 72 h.p.i. 9-16 cell embryos, while also investigating the effects of X-sorted semen on these events. We found a wide distribution of total cell numbers among embryos, attributed to an asynchronous cleavage pattern and blastomere death. Additionally, 13% of embryos displayed irregular shapes. The establishment of the inside cell compartment increased (p < 0.01) in embryos with more cells. However, only 53.8% of 16-cell embryos presented inside cells. Compaction was present in 32.4% embryos and was positively correlated (p = 0.03, OR 3.02) with the establishment of inside cells, occurring independently of cell number. Fragmentation was present in 36% embryos, being more frequent (p = 0.01) in embryos with lower cell numbers. A possible association between irregular shape and fragmentation was considered (p = 0.06). The use of X-sorted semen had no effect on most evaluated parameters. However, it did have a marked effect on cleavage rate (p < 0.01) and the arrest of 2- and 4- cell embryos. In conclusion, bovine embryos exhibit an asynchronous cleavage pattern, high levels of fragmentation, and demonstrate compaction and inside cell allocation later in development compared to mouse embryos. Semen X-sorting has major effects on cleavage and embryo arrest. Further studies are needed to elucidate the association between irregularly shaped embryos and fragmentation, as well as the effects of sex on inside cell allocation., (© 2024 Wiley-VCH GmbH. Published by John Wiley & Sons Ltd.)

Udder health has a crucial role in sustainable milk production, and various reports have pointed out that changes in udder condition seem to affect milk mineral content. The somatic cell count (SCC) is the most recognized indicator for the determination of udder health status. Recently, a new parameter, the differential somatic cell count (DSCC), has been proposed for a more detailed evaluation of intramammary infection patterns. Specifically, the DSCC is the combined proportions of polymorphonuclear neutrophils and lymphocytes (PMN-LYM) on the total SCC, with macrophages (MAC) representing the remainder proportion. In this study, we evaluated the association between DSCC in combination with SCC on a detailed milk mineral profile in 1,013 Holstein-Friesian cows reared in 5 herds. An inductively coupled plasma-optical emission spectrometry was used to quantify 32 milk mineral elements. Two different linear mixed models were fitted to explore the associations between the milk mineral elements and first, the DSCC combined with SCC, and second, DSCC expressed as the PMN-LYM and MAC counts, obtained by multiplying the proportion of PMN-LYM and MAC by SCC. We observed a significant positive association between SCC and milk Na, S, and Fe levels. Differential somatic cell count showed an opposite behavior to the one displayed by SCC, with a negative association with Na and positive association with K milk concentrations. When considering DSCC as count, Na and K showed contrasting behavior when associated with PMN-LYM or MAC counts, with decreasing of Na content and increasing K when associated with increasing PMN-LYM counts, and increasing Na and decreasing K when associated with increasing MAC count. These findings confirmed that an increase in SCC is associated with altered milk Na and K amounts. Moreover, MAC count seemed to mirror SCC patterns, with the worsening of inflammation. Differently, PMN-LYM count exhibited patterns of associations with milk Na and K contents attributable more to LYM than PMN, given the nonpathological condition of the majority of the investigated population. An interesting association was observed for milk S content, which increased with increasing of inflammatory conditions (i.e., increased SCC and MAC count) probably attributable to its relationship with milk proteins, especially whey proteins. Moreover, milk Fe content showed positive associations with the PMN-LYM population, highlighting its role in immune regulation during inflammation. Further studies including individuals with clinical condition are needed to achieve a comprehensive view of milk mineral behavior during udder health impairment., (© 2024, 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 study investigates the relationships between subclinical mastitis and milk quality with selected microRNAs in cow milk. California Mastitis Test (CMT)-positive (n = 20) and negative (n = 20) samples were compared (Experiment I). Additionally, samples with CMT-positive but microbiological-negative, as well as positive for only Staphylococcus subspecies (Staph spp.) and only Streptococcus subspecies (Strep spp.) were examined (Experiment II). Four groups were formed in Experiment II: Group I (CMT and microbiological-negative) (n = 20), Group II (CMT-positive but microbiological-negative) (n = 10), Group III (Staph spp.) (n = 5), Group IV (Strep spp.) (n = 5). While electrical conductivity, somatic cell count (SCC), malondialdehyde (MDA) increased, miR-27a-3p and miR-223 upregulated and miR-125b downregulated in the CMT-positive group in Experiment I. SCC and MDA were higher in CMT-positive groups. miR-27a-3p and miR-223 upregulated in Groups III and IV. While miR-155 is upregulated, miR-125b downregulated in Group IV. Milk fat is positively correlated with miR-148a and miR-223. As miR-27a-3p positively correlated with SCC and MDA, miR-125b negatively correlated with electrical conductivity and SCC. miR-148a and MDA were positively correlated. miR-155 was correlated with fat-free dry matter, protein, lactose, and freezing point. miR-223 was positively correlated with SCC and miR-148a. Results particularly highlight miR-27a-3p and miR-223 as potential biomarkers in subclinical mastitis, especially those caused by Staph spp. and Strep spp., while miR-148a, miR-155, and miR-223 stand out in determining milk quality., (© 2024 The Authors. Animal Science Journal published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Animal Science.)

The aim of this study was to examine the effects of milking cessation under different inflammatory conditions on the changes in antimicrobial components in milk and the process of mammary gland involution. Twenty udder halves were divided into two groups: those with (LPS) and without (control) lipopolysaccharide infusion, followed by cessation of milking for 8 weeks. Milk samples were collected weekly. Udder tissue was collected 4 weeks after milking cessation to measure the area of the lobule and connective tissue. After milking cessation, the somatic cell count (SCC) in the control group increased, whereas that in the LPS group did not. Lactoferrin (LF) and cathelicidin (Cath)-2 concentrations increased in both groups, whereas only LF was significantly lower in the LPS group than in the control group at week 4. The Cath-7 and S100A8 concentrations were significantly lower in the LPS group than in the control group. The lobule area was higher, and the connective tissue area was lower in the LPS group than in the control group. These results indicate that inflammation at milking cessation decreased the concentrations of some antimicrobial components and interfered with mammary gland involution. Therefore, animals with mastitis should recover prior to the onset of the dry period., (© 2024 Japanese Society of Animal Science.)

This observational study aimed to determine the association of cow-level factors and herd-level housing and management practices during the dry period with indicators of udder health in early-lactation cows in automated milking system (AMS) herds. Data were collected from 166 commercial AMS dairy farms (mean ± standard deviation = 116 ± 111 milking cows; range = 39 to 1,200) across Canada between October 2018 and September 2020. Information on herd demographics, housing, and management practices was obtained on each farm using 2 surveys. On each farm, we selected all cows that had available Dairy Herd Improvement (DHI) somatic cell count (SCC) data for their last milk test before dry-off (>250 d in milk) and their first milk test after calving (5-45 d in milk). Data from 14,007 cows were included after excluding cows with a dry period of <30 d and >120 d. Using the SCC data, we calculated for each cow the somatic cell score (SCS) for the last milk test before dry-off (PreSCS) and the first milk test after calving (PostSCS), which we then averaged per herd at a test-day level. Intramammary infection (IMI) was estimated using cow SCC data. Each cow was classified as not infected (SCC <200,000 cells/mL) or infected (SCC ≥200,000 cells/mL) at her last milk test before dry-off and her first milk test after calving. Based on this classification, cows were further categorized as never infected, always infected, new IMI, or cured IMI. At the cow level, a higher PostSCS was associated with longer dry periods. The odds of having a new IMI were higher for cows of higher parity and that had lower 305-d milk yield before dry-off. Cows with lower parity were more likely to cure an IMI. At the herd level, a higher 305-d milk yield before dry-off was associated with a lower incidence of new IMI and a higher incidence of cured IMI. Separating cows into a different pen as preparation for dry-off tended to be associated with a lower PostSCS and incidence of new IMI. At dry-off, herds that used teat sealants and blanket antibiotic dry cow therapy also had lower PostSCS. During the dry period, housing cows in different groups was associated with a higher PostSCS and a lower incidence of cured IMI, while housing cows in both pack pens and stalls compared with only pack pens was associated with a lower incidence of new IMI. Finally, placing cows onto the AMS to be milked one or more days after calving tended to be associated with a lower PostSCS compared with placing them in the AMS within the first day postpartum. In summary, indicators of udder health in early-lactation cows in AMS herds were associated with several cow-level factors and herd-level housing and management practices before dry-off, at dry-off, during the dry period, and at the beginning of lactation. Thus, if some of the associations identified are causal, AMS producers may be able to improve udder health through modifications of housing and management practices., (© 2024, 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/).)

Introduction: Mastitis is one of the most important factor diseases in dairy cattle worldwide. Milking technique represents one of the factors involved in the development of mastitis. The purpose of this study was to investigate the influence of vibrations during milking on the rate of clinical and subclinical mastitis. For this purpose, milking measurements, tank milk analyses and survey forms (general farm data, assessment of milking work and milking hygiene, teat condition, feeding, farm problems, animal behavior) were assessed in 8 Swiss dairy farms. The results show a correlation between present vibrations at the output of the milk meter and increasing bulk milk somatic cell count. Further, a tendency was shown for vibrations at the input of the milk meter to influence bulk milk somatic cell count. Also, a tendency regarding vibrations at the outlet of the milk meter and acute phase protein milk amyloid A was evident. In conclusion, the results suggest that vibration during milking might have a negative effect on udder health. However, further research with a larger number of dairies is needed to make a more generally valid statement.

"India is the world's leading producer of milk" and demands a non-invasive diagnostic tool like infrared thermography (IRT) to identify the costliest production disease, mastitis. It can form the basis of precision dairy farming. Therefore, the present study focuses on thermal imaging of the udder and teat quarters of Sahiwal cows during different seasons to identify subclinical (SCM) and clinical mastitis (CM) cases using the Darvi DTL007 camera. A total of 24-69 lactating Sahiwal cows were screened out using IRT regularly throughout the year. The intramammary infection status was further assessed using the CMT. The receiver operating characteristic analysis was carried out to develop the current study's cut-off for various thermographic parameters. The incidence for SCM and CM ranged from 26.47 to 38.75% and 17.83-22.79%, respectively during different seasons in Sahiwal udder quarters. The thermogram analysis revealed a significant difference (p < 0.01) in the mean values of the udder and teat surface temperature of Sahiwal cows between healthy, SCM, and CM during different seasons. The mean values of udder skin surface temperature (USST) during different seasons ranged between 29.07 and 36.91 °C, 31.51 to 37.88 °C and 32.42 to 38.79 °C among healthy, SCM, and CM-affected quarters, and correspondingly, the mean values of teat skin surface temperature (TSST) were 28.28 to 36.77 °C, 30.68 to 37.88 °C and 31.70 to 38.73 °C, respectively. Further results revealed an increase (p < 0.01) in the mean values of USST during winter, summer, rainy, and autumn as 2.44, 3.35; 0.97, 1.88; 1.06, 1.83; 1.29, 2.39 °C and TSST as 2.4, 3.42; 1.11, 1.96; 1.21, 2.19, 1.3, 2.4 °C of SCM, CM-affected quarters to healthy quarters, respectively, in Sahiwal cows. Thermograms showed a strong positive correlation with the CMT scores of SCM, CM cases, and healthy samples. Henceforth, irrespective of the seasons studied in the present work, IRT is an efficient, supportive tool for the early identification of subclinical mastitis., Competing Interests: Declaration of Competing Interest “None.”, (Copyright © 2023 Elsevier Ltd. All rights reserved.)

As clinical mastitis (CM) treatments are responsible for a large portion of antimicrobial use on dairy farms, many selective CM treatment protocols have been developed and evaluated against a blanket treatment approach of CM cases. Selective treatment protocols use outcomes of diagnostic tests to exclude CM cases from antimicrobial treatment when they are unlikely to benefit. To tailor interventions to increase uptake of selective treatment strategies, a comprehension of current on-farm treatment practices and factors affecting treatment decisions is vital. Two questionnaires were conducted among 142 farms across 5 provinces participating in the Canadian Dairy Network for Antimicrobial Stewardship and Resistance in this cross-sectional study. Self-reported adoption of selective CM treatments by dairy farmers was 64%, with median of 82% of cows treated in those herds using selective treatment. Using logistic regression models, the odds to implement a selective CM treatment protocol increased with a decreasing average cow somatic cell count. No other associations were identified between use of a selective CM treatment protocol and farm characteristics (herd size, CM incidence, province, milking system, and housing system). Three subsets of farmers making cow-level CM treatment decisions were identified using a cluster analysis approach: those who based decisions almost exclusively on severity of clinical signs, those who used various udder health indicators, and farmers who also incorporated more general cow information such as production, age, and genetics. When somatic cell count was considered, the median threshold used for treating was >300,000 cells/mL at the last Dairy Herd Improvement test. Various thresholds were present among those considering CM case history. Veterinary laboratories were most frequently used for bacteriological testing. Test results were used to start, change, and stop treatments. Regardless of protocol, reasons for antimicrobial treatment withheld included cow being on a cull list, having a chronic intramammary infection, or being at end of lactation (i.e., close to dry off). If clinical signs persisted after treatment, farmers indicated that they would ask veterinarians for advice, stop treatment, or continue with the same or different antibiotics. Results of this study can be used to design interventions targeting judicious mastitis-related antimicrobial use, and aid discussions between veterinarians and dairy producers regarding CM-related antimicrobial use., (© 2024, 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/).)

In the buffalo dairy sector, a huge effort is still needed to improve mastitis prevention, detection, and management. Electrical conductivity (EC) and total somatic cell count (SCC) are well-known indirect indicators of mastitis. Differential somatic cell count (DSCC), which represents the proportion of neutrophils and lymphocytes on the total SCC, is instead a novel phenotype collected in the dairy cattle sector in the last lustrum. As little is known about this novel trait in dairy buffalo, in the present study we explored the nongenetic factors affecting DSCC, as well as EC and total somatic cell score (SCS), in the Italian Mediterranean buffalo. The data set used for the analysis included 14,571 test-day (TD) records of 1,501 animals from 6 herds, and climatic information of the sampling locations. The original data were filtered to exclude animals with less than 3 TD per lactation and, for the investigated traits, outliers beyond 4 standard deviations. In the statistical model we included the fixed effects of herd (6 classes), days in milk (DIM; 10 classes of 30 d, with the last being an open class until 360 d), parity (6 classes, from 1 to 6+), year-season of calving (11 classes, from summer 2019 to winter 2021/2022), year-season of sampling (9 classes, from spring 2020 to spring 2022), production level (4 classes based on quartiles of average milk yield by herd), and temperature-humidity index (THI; 4 classes based on quartiles, calculated using the average temperature and relative humidity of the 5 d before sampling). Average EC, SCS, and DSCC vary across herds. Considering DIM, greater EC values were observed at the beginning and the end of lactation; SCS was slightly lower, but DSCC was greater around the lactation peak. Increased EC, SCS, and DSCC levels with increasing parity were reported. Year-season calving and year-season sampling only slightly affected the variation of the investigated traits. Milk of high-producing buffaloes was characterized by lower EC and SCS mean values, nevertheless it had slightly greater DSCC percentages. Buffaloes grouped in the highest THI classes (classes 3 and 4) showed, on average, greater EC, SCS, and DSCC in comparison to the lower classes, especially to class 2. Results of the present study represent a preliminary as well as necessary step for the possible future inclusion of EC, SCS, or DSCC in breeding programs aimed to improve mastitis resistance in dairy buffaloes., (© 2024, 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 production of high-quality and safe milk is closely associated with the udder health of dairy cows. While there are many mastitis diagnostic tests/methods available, choosing the most appropriate diagnostic test for a sustainable udder health control program could be a challenge. This study was aimed at selecting tests for the screening of subclinical mastitis on small- and large-scale dairy farms in Türkiye, using multi-criteria decision-making methods. An integrated approach employing the analytical hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) together was used to select subclinical mastitis screening tests for on-farm use. While the AHP determines the weights of the evaluation criteria, the TOPSIS provides a final ranking. Nine different subclinical mastitis screening (SCM) methods (DeLaval somatic cell counter, PortaSCC test, California mastitis test (CMT), rapid culture, portable/hand-held electrical conductivity meter, infrared thermography, leukocyte esterase strip test, milk pH, UdderCheck test) were analyzed on the basis of five selection criteria (the market availability of the test, the diagnostic accuracy of the test, the cost of the test, the cow-side use of the test, and the practicality of the test). The selection criteria were determined based on literature review and stakeholder input. The weighting of the criteria with the AHP was based on the pairwise comparison of the criteria by stakeholders. The criteria were weighted from 1 to 9 according to their relative importance as follows: "1: equally important," "3: moderately important," "5: strongly important," "7: very strongly important," "9: extremely important," and "2, 4, 6, 8: intermediate values." Final ranking of SCM tests with the TOPSIS was based on the stakeholder evaluations of fulfillment of the criteria by the alternatives. The most appropriate screening test for both large- and small-scale dairy farms was determined to be the CMT. The CMT is a very useful, easy to perform, and low-cost tool for detecting subclinical mastitis. Being a major element of udder health control programs, the CMT, if regularly used on dairy farms in Türkiye, would enable the culling of chronically infected animals and the reduction of mastitis-associated economic losses. Furthermore, regular CMTs would contribute to reducing milk SCC and improving milk quality. In conclusion, multi-criteria decision-making methods not only provide a systematic approach that may assist both veterinarians and farmers in deciding on the best choice among the different tests available for the screening of subclinical mastitis but also offer potential benefits to policymakers, researchers, and other industry stakeholders., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

Background: Milk produced by dairy cows is a complex combination of many components, but the effect of mastitis has only been investigated for a few of these components. Milk mid-infrared (MIR) spectra can reflect the global composition of milk, and this study aimed to detect the relationships between milk MIR spectral wavenumbers and milk somatic cell count (SCC)-a sensitive biomarker for mastitis., Methods: Pearson correlation analysis was used to calculate the correlation coefficient between somatic count score (SCS) and spectral wavenumbers. A general linear mixed model was applied to investigate the effect of three different classes of SCC (low, middle and high) on spectral wavenumbers., Results: The mean correlation coefficient between the 'fingerprint region' (wavenumbers 925-1582 cm -1 ) and the SCS was higher than that for other regions of the MIR spectrum, and the specific wavenumber with the strongest correlation with the SCS was within the 'fingerprint region'. SCC class had a significant (p < 0.05) effect on 639 spectral wavenumbers. In particular, some spectral wavenumbers within the 'fingerprint region' were highly affected by the SCC class., Limitation: The data were collected from only one province in China, so the generalisability of the findings may be limited., Conclusion: SCC had close relationships with milk spectral wavenumbers related to important milk components or chemical bonds., (© 2023 British Veterinary Association.)