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We recently demonstrated that conceptus-derived interferon tau (IFNT), responsible for maternal recognition in cattle, acts on the uterus in a dose- and time-dependent manner by upregulating key interferon-stimulated genes (ISGs) in the endometrium. In high producing dairy cows, postpartum uterine infection is a major factor influencing fertility and pregnancy outcome. Lipopolysaccharide (LPS), an endotoxin of Gram-negative bacteria such as Escherichia coli , generates an altered uterine environment by inducing excessive inflammation at the maternal-conceptus interface. Thus, we aimed to investigate whether the endometrial response to IFNT is altered in the presence of LPS. Endometrial explants were isolated from uteri collected at a local abattoir from Holstein Friesian cows (n = 8) during the mid-luteal stage of the estrous cycle, and cultured in RPMI medium for 24 h in 5 % CO 2 in humidified air without (control), or with IFNT (100 ng/mL), a single Day 15 conceptus, LPS (1 μg/mL), both IFNT and LPS, or both a Day 15 conceptus and LPS. Incubation with IFNT and a Day 15 conceptus up-regulated (P < 0.05) well-known classical ISGs (ISG15 , OAS1 , MX1 and MX2) as well as other candidate ISGs (CMPK2 , IFI35 , TRIM38 and TNFSF10) and down-regulated expression of IL1B in endometrial explants. Incubation with LPS increased (P < 0.05) abundance of NFKB1 (a key transcription factor involved in inflammatory and immune response), TNFA , IL1B and IL6 (pro-inflammatory cytokines), IL10 (anti-inflammatory cytokine), IL8 , CXCL1 , CXCL3 and CCL2 (chemokines), and, to a lesser extent, classical ISGs in endometrial explants. However, LPS did not alter endometrial response to IFNT, irrespective of IFNT concentration (1, 10 or 100 ng/mL). Results suggest that the expression of ISGs, up-regulated by conceptus-derived IFNT, is not altered in the endometrium in the presence of LPS; however, the increased expression of inflammation-related genes induced by LPS indicate an altered endometrial immune response that may be associated with compromised pregnancy establishment or pregnancy failure. • Conceptus-derived interferon tau (IFNT) induces interferon-stimulated genes (ISGs) in the endometrium. • Bacterial lipopolysaccharide (LPS) does not influence endometrial ISG expression in response to conceptus-derived IFNT. • Inflammatory genes induced by LPS may be associated with compromised pregnancy establishment or pregnancy failure. [ABSTRACT FROM AUTHOR]

Case History: In spring 2021, on a seasonally calving, pastorally based, Taranaki dairy farm, 12 first-calving heifers (≤ 30 days post-calving) developed similar dry, red to black, crusting lesions on the medial aspect of the teat udder junction extending down the medial teat. Some cows had multiple teats affected. Treatment was initially unrewarding and did not slow the progression of the disease. Overall, 8/12 cows recovered, and 4/12 cows were culled, with three of the cows culled after a teat sloughed and the fourth after surgical amputation of a teat. Outbreaks of the same condition, on the same farm but affecting fewer animals, occurred in spring 2022 (n = 6) and spring 2023 (n = 3). Clinical Findings: An initial scab-like or crusting lesion progressed to resemble a thick eschar consisting of very dry and hard dead tissue. The unaffected areas of the teat felt normal but immediately under the dead tissue, there was a warm, firmer area consistent with an inflammatory reaction. Removing the scab led to profuse bleeding, with no visible bed of granulation underneath the scab. There was no leaking of milk in those cows that lost a teat, and no smell to the lesions themselves. Serology and virology ruled out the involvement of bovine alphaherpesvirus (BoHV-2) bovine gammaherpesvirus (BoHV-4), orthopoxviruses (cowpox) and parapoxviruses (pseudocowpox). Histopathology of an affected and surgically amputated teat showed multifocal erosion and ulceration of the epidermis, covered by a thick serocellular crust. In areas of ulceration, there were numerous neutrophils, and the dermis was expanded by granulation tissue with variable numbers of neutrophils, eosinophils, and lymphocytes around small blood vessels. Diagnosis: Based on the similarity of the history, presentation, and histopathological changes to those described for a novel disease reported in the UK, a diagnosis of ischaemic teat necrosis (ITN) was made. Clinical Relevance: If ITN is an emerging condition in New Zealand and becomes as prevalent as it has in the UK, clinicians will be confronted with a significant new welfare problem in dairy cows. Anecdotally, there have been reports of other ITN outbreaks in New Zealand, and the Ministry for Primary Industries would be interested in collating reports from other New Zealand veterinarians. [ABSTRACT FROM AUTHOR]

Introduction: The current global concern over increasing antimicrobial resistance among animal and human pathogens has motivated efforts to reduce antimicrobial drug use in food animals and its impact on antimicrobial resistance. One such strategy is to use selective dry cow therapy (SDCT) in dairy cows, which involves treating only cows with intramammary infection (IMI) at dry-off. However, efficient methods are needed to identify cows with IMI at dryoff to implement SDCT. Automatic Milking Systems (AMS) data may help farmers identify cows with IMI when individual Somatic Cell Count (SCC) is not routinely tested. This study assessed the correlation between cow-level and quarter-level AMS parameters and IMI at dry-off. Methods & Results: A total of 733 udder quarters (comprising both Primiparous [PRIM] and Multiparous [MULT] cows) were sampled and categorized for IMI based on bacterial growth and SCC. Data were aggregated both daily and into 7- day and 15-day intervals preceding dry-off. The quarter-level prevalence of bacterial growth at dry-off was 24.28% overall. When stratified by parity, logistic regression analysis at 15 days to dry-off revealed that the average difference in mastitis detection index (MDi) in PRIM, MDi, and standard deviation milk flow rate in MULT were associated with increased odds of IMI at dry-off. Similarly, data from 7 days to dry-off revealed that average peak milk flow rate in PRIM, and MDi in MULT were associated with increased odds of IMI at dryoff. However, an increase in average milk yield was associated with decreased odds of IMI. Discussion & Conclusion: Our findings underscore the significance of MDi, milk flow rate, peak milk flow rate, and milk yield in predicting IMI at dry-off. Notably, stronger associations were observed with data collected 7 days preceding dryoff. Further research is warranted to refine and validate algorithms amalgamating these variables for precise IMI prediction in cows at dry-off. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate interleukin-8 (IL-8) as a biomarker for udder inflammation in dairy cows and to explore its associations with various metabolic parameters indicative of systemic inflammation and metabolic dysregulation. Dairy cows (multiparous) were categorized into five somatic cell count (SCC) classes: Class I (<100,000 cells/mL; n = 45), Class II (100,000–200,000 cells/mL; n = 62), Class III (201,000–400,000 cells/mL; n = 52), Class IV (401,000–1,000,000 cells/mL; n = 73), and Class V (>1,000,000 cells/mL; n = 56). The study quantified IL-8 levels and analyzed their correlations with NEFAs (non-esterified fatty acids), BHBA (beta-hydroxybutyrate), GGTP (gamma-glutamyltransferase), and AspAT (aspartate aminotransferase). IL-8 concentrations demonstrated a significant and progressive increase across the SCC classes, establishing a strong positive correlation with SCC (p < 0.01). Additionally, IL-8 levels exhibited positive correlations with GGTP (p < 0.01) and AspAT (p < 0.01), indicating that elevated IL-8 is associated with increased hepatic enzyme activities and potential liver dysfunction. Furthermore, IL-8 showed significant positive correlations with NEFAs (p < 0.01) and BHBA (p < 0.05), linking higher IL-8 levels to metabolic disturbances such as ketosis and negative energy balance. Variations in metabolic parameters, including NEFAs, BHBA, GGTP, and AspAT, across the SCC classes underscored the association between elevated SCC levels and metabolic dysregulation in dairy cows. These findings highlight the interrelated nature of the inflammatory responses and metabolic disturbances in dairy cattle, emphasizing that an elevated SCC not only signifies udder inflammation but also correlates with systemic metabolic alterations indicative of ketosis and liver damage. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to investigate the potential of scoring dairy cattle standing in the milking parlour, known as 'In-Parlour Scoring' (IPS), as an alternative method to locomotion scoring. A total of 990 observations were conducted on 495 cows across eleven Austrian dairy farms equipped with herringbone, side-by-side, or tandem milking parlours by two investigators. The IPS indicators included shifting weight, claw conformation, and visible disorders of the distal limb. Locomotion scoring, using five different scores, was carried out on these 495 cows after the second round of IPS. The indicators of shifting weight, abnormal weight distribution, swollen heel, hock joint or interdigital space, skin lesions on the lateral hock, claw position score, digital dermatitis lesions, short dorsal claw wall, and hyperextension of one claw were determined to be useful in predicting lameness, defined as a locomotion score (LCS) ≥ 3. The ability to correctly designate a cow as non-lame (LCS ≤ 2) was calculated to be at least ≥ 96% (specificity). However, the ability to correctly predict a lame cow was only 24% or less (sensitivity). We conclude that a one-time IPS has limited suitability for lameness detection on Austrian dairy farms with herringbone, side-by-side, and tandem milking parlours. The objective of this study was to evaluate the potential of 'In-Parlour Scoring' (IPS) as an alternative to locomotion scoring in herringbone, side-by-side, and tandem milking parlours in Austria. Between January and May 2023, a total of 990 observations were conducted on 495 cows across eleven Austrian dairy farms by two investigators working simultaneously but independently of each other. The observation criteria included shifting weight, claw conformation, and obvious disorders of the distal limb. Locomotion scoring was conducted on all cows within 24 h of assessment in the milking parlour using a scale of 1 to 5 (LCS 1: not lame; LCS 5: severely lame). Functional hoof trimming was performed within ten days after IPS. The following indicators were identified as useful for predicting lameness (LCS ≥ 3): shifting weight, abnormal weight distribution, swollen heel, hock joint or interdigital space, skin lesion on the lateral hock, claw position score, digital dermatitis lesions, short dorsal claw wall, and hyperextension of one claw. The reliability of the individual indicators for intra- and inter-rater assessment exhibited considerable variation ((weighted) kappa values: −0.0020–0.9651 and −0.0037–1.0, respectively). The specificity and sensitivity for the prediction of lame cows were calculated to be ≥ 96% and ≤ 24%, respectively. It was demonstrated that a one-time IPS has limited suitability for lameness assessment on Austrian dairy farms with herringbone, side-by-side, and tandem milking parlours. [ABSTRACT FROM AUTHOR]

Simple Summary: This study evaluated the effects of heat stress on the productivity of dairy cows. During the experimental period, THI values ranged from 46.9 to 81.0, with the most severe heat stress occurring in August. A decrease in productivity was observed when the THI exceeded 72. It was found that milk production took about one month to recover after the high-temperature period ended. The THI ratio, calculated based on the daily THI distribution, showed a strong negative correlation with rumen temperature (− 0.744; p < 0.001). During periods of significant productivity decreases due to high-temperature stress, rumen temperatures were higher than 39.15 °C. Based on the rumen temperature and daily THI distribution, it is suggested that these findings could serve as foundational data for developing technologies to manage high-temperature environments for dairy cows. This study was conducted to evaluate the effects of high-temperature stress on dairy cow productivity and the correlation between rumen sensors. The data were collected on the temperature, humidity, milk productivity, milk components, blood components, and rumen sensor data from 125 dairy cows during the experimental period (1 May 2020 to 30 October 2020). High-temperature stress of dairy cows was evaluated based on the temperature–humidity index (THI). The correlations between the high-temperature stress, productivity, and sensor data were analyzed using SAS and R programs. The THI ranged from 46.9 to 81.0 during the experimental period, and a significant decrease was observed in the milk production of dairy cows during August (p < 0.05). Milk production was evaluated to decrease by 1.8% because of high-temperature stress during the experimental period. There was a significantly high negative correlation between the THI ratio of day and rumen temperature (r = 0.744; p < 0.001). The other rumen sensor data did not show a significant correlation with the productivity of dairy cows. The results can be utilized as a guideline for managing temperature and humidity to maintain dairy cow productivity on farms in high-temperature stress conditions. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The nutritional components and quality of milk are influenced by the rumen microbiota and its metabolites at different lactation stages. Hence, rumen fluid and milk samples from 6 dairy cows fed the same diet were collected during peak lactation, early mid-lactation, and later mid-lactation. Untargeted metabolomics and 16S rRNA sequencing were applied for analyzing milk and rumen metabolites, as well as rumen microbial composition, respectively. The levels of lipid-related metabolites, l-glutamate, glucose-1-phosphate, and acetylphosphate in milk exhibited lactation-dependent attenuation. Maltol, N -acetyl-d-glucosamine, and choline, which are associated with milk flavor or coagulation properties, as well as l-valine, lansioside A, clitocine, and ginsenoside La, increased significantly in early mid-lactation and later mid-lactation, especially in later mid-lactation. The obvious increase in rumen microbial diversities (ACE and Shannon indices) were observed in early mid-lactation compared with peak lactation. Twenty-one differential bacterial genera of the rumen were identified, with Succinivibrionaceae_UCG-001 , Candidatus Saccharimonas , Fibrobacter , and SP3-e08 being significantly enriched in peak lactation. Rikenellaceae_RC9_gut_group , Eubacterium_ruminantium_group , Lachnospira , Butyrivibrio , Eubacterium_hallii_group , and Schwartzia were most significantly enriched in early mid-lactation. In comparison, only 2 bacteria (unclassified_f__Prevotellaceae and Prevotellaceae_UCG-001) were enriched in later mid-lactation. For rumen metabolites, LysoPE(16:0), l-glutamate, and l-tyrosine had higher levels in peak lactation, whereas PE(17:0/0:0), PE(16:0/0:0), PS(18:1(9Z)/0:0), l-phenylalanine, dulcitol, 2-(methoxymethyl)furan, and 3-phenylpropyl acetate showed higher levels in early mid-lactation and later mid-lactation. Multiomics-integrated analysis revealed that a greater abundance of Fibrobacter contributed to phospholipid content in milk by increasing ruminal acetate, l-glutamate, and LysoPE(16:0). Prevotellaceae_UCG-001 and unclassified_f_Prevotellaceae provide substrates for milk metabolites of the same category by increasing ruminal l-phenylalanine and dulcitol contents. These results demonstrated that milk metabolomic fingerprints and critical functional metabolites during lactation, and the key bacteria in rumen related to them. These findings provide new insights into the development of functional dairy products. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Mycoplasmosis (due to infection with Mycoplasma bovis) is a serious disease of beef and dairy cattle that can adversely affect health, welfare, and productivity. Mycoplasmosis can lead to a range of often severe, clinical presentations. Mycoplasma bovis infection can present either clinically or subclinically, with the potential for recrudescence of shedding in association with stressful periods. Infection can be maintained within herds because of intermittent shedding. Mycoplasma bovis is recognized as poorly responsive to treatment, which presents a major challenge for control in infected herds. Given this, particular focus is needed on biosecurity measures to prevent introduction into uninfected herds in the first place. A robust and reliable laboratory test for surveillance is important for both herd-level prevention and control. The objective of this study was to estimate the sensitivity (Se) and specificity (Sp) of 3 diagnostic tests (1 PCR and 2 ELISA tests) on bulk tank milk (BTM), for the herd-level detection of M. bovis using Bayesian latent class analysis (BLCA). In autumn 2018, BTM samples from 11,807 herds, covering the majority of the main dairy regions in Ireland had been submitted to the Department of Agriculture testing laboratory for routine surveillance and were made available for study. A stratified random sample approach was used to select a cohort of herds for testing from this larger sample set. A final study population of 728 herds had BTM samples analyzed using a Bio-X ELISA (ELISA 1), an IDvet ELISA (ELISA 2) and a PCR test. A BLCA was conducted to estimate the Se and Sp of the 3 diagnostic tests applied to BTM for the detection of herd-level infection. An overall latent class analysis was conducted on all herds within a single population (a 3-test, 1-population model). The herds were also split into 2 populations based on herd size (small herds had <82 cattle; a 3-test, 2-population model) and separately into 3 regions in Ireland (Leinster, Munster, and Connacht/Ulster; a 3-test, 3-population model). The latent variable of interest was the herd-level M. bovis infection status. In total, 363/728 (50%) were large herds, 7 (1.0%) were positive on PCR, 88 (12%) positive on ELISA 1, and 406 (56%) positive on ELISA 2. Based on the 2-population model, the Se (95% Bayesian credible interval [BCI] was 0.03 (upper and lower limits: 0.02, 0.05), 0.22 (0.18, 0.27), and 0.94 (0.88, 0.98) for PCR, ELISA 1, and ELISA 2, respectively. The Sp (95% BCI) was 0.99 (0.99, 1.0), 0.97 (0.95, 0.99), and 0.92 (0.86, 0.97) for PCR, ELISA 1, and ELISA 2, respectively. The herd-level true prevalence was estimated at 0.43 (BCI 0.35, 0.5) for smaller herds. The true prevalence was estimated at 0.62 (BCI 0.55, 0.69) for larger herds. The true prevalence was estimated at 0.56 (BCI 0.49, 0.463) in the 1-population model. For the 3-population model, the Se (95% BCI) was 0.03 (0.02, 0.05), 0.24 (0.18, 0.29), and 0.95 (0.9, 0.98) for PCR, ELISA 1, and ELISA 2 respectively. The Sp (95% BCI) was 0.99 (0.99, 1.0), 0.98 (0.96, 0.99), and 0.88 (0.79, 0.95) for PCR, ELISA 1 and ELISA 2, respectively. The herd-level true prevalence (95% BCI) was estimated at 0.65 (0.56, 0.73), 0.38 (0.28, 0.46), and 0.53 (0.4, 0.65) for populations 1, 2, and 3 respectively. Across all 3 models, the range in true prevalence was 38% to 65% of Irish dairy herds infected with M. bovis. The operating characteristics vary substantially between tests. The IDvet ELISA had a relatively high Se (the highest Se of the 3 tests studied) but it was estimated at 0.95 at its highest in 3-test, 3-population model. This test may be an appropriate test for herd-level screening or prevalence estimation within the context of the endemically infected Irish dairy cattle population. Further work is required to optimize this test and its interpretation when applied at herd-level to offset concerns related to the lower than optimal test Sp. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The CellCheck dry cow consult (DCC) was developed by the CellCheck Technical Working Group to enable farmers to engage with their nominated veterinarian to develop farm-specific selective dry cow therapy (SDCT) plans, where appropriate. This study evaluated the effect of the DCC on farmer decision-making around dry cow therapy, and the udder health effects of implementing SDCT, in study herds over the 2019 and 2020 dry periods. The DCC was a 3-h consult, delivered and funded as part of the Targeted Advisory Service on Animal Health. Herds that completed a DCC were invited to register for a dry cow review the following year. The combined dataset for analysis across both years comprised 439 herds and 25,357 cows. Herd size ranged from 25 to 800. The median SCC of cows dried off with teat sealant only was 47,000 cells/mL before drying off in 2019 and 48,000 cells/mL at first milk recording in 2020, and 43,000 cells/mL before drying off in 2020 and 39,000 cells/mL at first milking recording in 2021. Following both the 2019 and 2020 dry periods, cows tended to converge toward a similar median SCC early in the following lactation, irrespective of prior dry cow treatment strategy. The uptake of SDCT was greater in review herds, with 21% of cows receiving teat sealant only in 2020, compared with 16.3% of cows in herds participating in a consult for the first time in 2020. At an individual cow level, in both years dry period new infection rate (NIR) was approximately 2.7% higher for cows treated with teat sealant only, than for those treated with both dry cow antibiotic tubes and teat sealant, and 1.2% higher than cows treated with antibiotic only. Regardless of treatment, a significant association was detectable between increasing parity and the risk of a dry period new infection. Increasing herd size had a significant effect on the risk of dry period NIR. At a herd level, no significant increase in NIR occurred when SDCT was used compared with herds where blanket dry cow therapy was used. Though not without risk, SDCT can be successfully implemented in Irish herds; however, constant attention to hygiene and management is essential. Despite the challenges, facilitating continued farmer education and engagement with professional guidance will be important. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. In modern breeding systems, cows are subjected to many stress factors. Animals fed a high-grain diet may have a decreased rumen pH, which would lead to subacute ruminal acidosis syndrome. The aim of this study was to investigate the evolution of microbial community composition in cows undergoing a dietary stress challenge. Twelve cows were subjected to a challenge period that consisted of a rapid change of ration, from a normal (45.4:54.6 forage:concentrate) to a high-grain content diet (24.8:75.2 forage:concentrate) to induce subacute ruminal acidosis. Individual rumen fluid content samples were collected before (T0) and during the challenge (T3, T14, T28). The DNA from rumen contents was extracted, purified, and sequenced to evaluate bacterial populations, and sequencing was performed on Illumina MiSeq. The effect of animal conditions on rumen microbial community was quantified through a linear mixed model. The acidogenic diet created 2 main clusters: ruminal hypomotility (RH) and milk fat depression (MFD). The microbial composition did not differ in T0 between the 2 groups, whereas during the challenge Ruminococcus spp., Treponema spp., Methanobrevibacter spp., and Methanosphaera spp. concentrations increased in RH cows; and Succinivibrio spp. and Butyrivibrio spp. concentrations increased in MFD cows. Prevotella spp. and Ruminococcus spp. were negatively correlated, whereas the Christenellaceae family was positively correlated with both Methanobrevibacter spp. and Methanosphaera spp. Moreover, the same diet affected cows' microbiota composition differently, underlying the impact of the host effect. Other studies are necessary to deepen the relationship between microbiota composition and host. [ABSTRACT FROM AUTHOR]

Background/Objectives: The negative energy balance activaties of spontaneous lipolysis. This may promotes inflammation within the adipose tissue. The aim of the study was to explain the development of inflammation during increased lactogenesis. It was hypothesized that lipolysis contributes synthesis of interleukin-6 and plasminogen. Methods: The study was in production conditions carried out using Holstein-Friesian cows. The period studied covered time of early lactation. Results: Up to the peak of lactation, milk yield strongly influenced the rate of loss of body condition. This had an impact on with the intensity of the release of the fatty acids. In both cases this relationships strengthened to the peak of production. Oobserved tendencies towards a decrease in the concentration of glucose and an increase in that of leptin. Loss of the body condition and the release of NEFA were were influencing to affect the blood concentrations of interleukin-6 and plasminogen. We have shown that IL-6 has a relatively strong correlation with the NEFA. They correlate with IL-6 independently of EB influence. This may suggest independent associations between these variables, which could potentially be applied in practice. Conclusions: The NEFA release in the long term can increase the inflammatory response within adipose tissue and can intensify the release of interleukin-6 and plasminogen. It is likely that in the initial stage of lactogenesis, the inflammatory process developing within adipose tissue is physiologically justified. Our results can provide background to this little-described area of research. [ABSTRACT FROM AUTHOR]

Simple Summary: A mechanical brush is currently used as a grooming tool to enhance the well-being of dairy cows and improve their overall environment. In the present study, we collected comprehensive data on the use of mechanical brushes by domestic dairy cows during the lactation, dry, and perinatal periods and the consequent effects on their lactation performance, health status, and reproductive performance. The findings of our study suggest that the frequency and duration of mechanical brush usage were significantly higher for brushes installed on the middle door than for brushes installed near the wall. Furthermore, the head was the preferred body part for grooming during the lactation and dry periods. Mechanical brush usage reduced postpartum stress in dairy cows, promoted blood circulation, improved the cleanliness of the body's surface, enhanced milk production of lactating cows, and increased the progesterone concentration of pregnant dairy cows after artificial insemination (AI). Thus, the installation of mechanical brushes at appropriate positions in dairy farms can improve the production performance of dairy cows and enhance milk yield. Intensive farming can reduce production costs and maximize animal production efficiency; however, it also causes many adverse effects on the welfare of dairy cows. A mechanical brush is an automated grooming device that promotes the grooming behavior of dairy cattle, thereby helping to alleviate stress. In the present study, we evaluated the effects of using mechanical brushes on the production performance of dairy cows by comprehensively analyzing their milk production, health status, and reproductive performance. The cows were assigned to 6 groups: 109 lactating dairy cows (brush treatment) and 105 controls (without brush treatment), 64 dry milk dairy cows (brush treatment) and 49 controls (without brush treatment), and 198 perinatal cows (brush treatment) and 65 controls (without brush treatment). We found an increasing trend in the daily utility time and usage frequency of mechanical brushes for each cow during the lactating period (7.73 ± 4.02 min/d and 2.90 ± 1.22 times/d, respectively), dry period (15.97 ± 14.16 min/d and 4.21 ± 2.91 times/d, respectively), and perinatal period (25.15 ± 19.05 min/d and 5.45 ± 3.83 times/d, respectively) (p < 0.01 and p < 0.05, respectively). The installation location of the mechanical brush significantly affected the frequency of its usage during the different periods. The head was the preferred body part for using the mechanical brush during the lactation and dry periods (59.32% and 44.54%, respectively), while the hip was the main preferred grooming part during the perinatal period (40.17%). Overall, the time, frequency, and preferred body part of dairy cows that used mechanical brushes varied across different physiological stages. Additionally, mechanical brush use in lactating and dry dairy cows significantly improved cleanliness of the body's surface (p < 0.05) and enhanced milk production of lactating cows (p < 0.01), particularly for cows with four and five parities. Thus, the use of mechanical brushes could improve the production performance of dairy cows and enhance sustainability of large-scale farms. [ABSTRACT FROM AUTHOR]

The cytokine context present in the reproductive tract of cows is closely involved in normal uterine functions, including the estrous cycle and the establishment and maintenance of pregnancy. However, the roles of some cytokines in the uterus, and their relation with reproductive performance remain to be elucidated. Thus, this study aimed to examine the protein expression of several cytokines such as TNFα, IL-6, IL-8, IFNγ, IL-4, and TGF-β3 in endometrial biopsies previous to conception, to evaluate the possible association with delayed conception in dairy cows. Protein expression levels were evaluated by immunohistochemistry. Results showed that the protein expression levels of TNFα, IL-6, IL-4 and TGF-β3 were not associated with the parturition-conception interval, whereas the high protein expression levels of IFNγ were associated with the parturition-conception interval. Finally, the low protein expression of IL-8 showed a statistical tendency to be associated with delayed conception. This is the first report about the protein expression of IFN-γ in the endometrium of dairy cows and also, this cytokine could enhance the favorable conditions to achieve an early pregnancy. [ABSTRACT FROM AUTHOR]

Bovine mastitis is one of the main inflammatory diseases that can affect the udder during lactation. Somatic cell counts and sometimes microbiological tests are routinely adopted during monitoring diagnostics in dairy herds. However, subclinical mastitis is challenging to identify, reducing the possibility of early treatments. The main aim of this study was to investigate the miRNome profile of extracellular vesicles isolated from milk as potential biomarkers of subclinical mastitis. Milk samples were collected from a total of 60 dairy cows during routine monitoring tests. Small RNA sequencing technology was applied to extracellular vesicles of milk samples collected from cows classified according to the somatic cell count to identify differences in the miRNome between mastitic and healthy cows. A total of 1997 miRNAs were differentially expressed between both groups. Among them, 68 miRNAs whose FDRs were < 0.05 were mostly downregulated, with only one upregulated miRNA (i.e., miR-361). Functional analysis revealed that miR-455-3p, miR-503-3p, miR-1301-3p and miR-361-5p are involved in the regulation of several biological processes related to mastitis, including immune system-related processes. This study suggests the involvement of extracellular vesicle-derived miRNAs in the regulation of mastitis. Moreover, these findings provide evidence that miRNAs from milk extracellular vesicles can be used to identify biomarkers of mastitis. However, further studies must be conducted to validate these miRNAs, especially for subclinical diagnosis. [ABSTRACT FROM AUTHOR]

The widespread adoption of automatic milking systems (AMS) in the United States has afforded dairy cows the flexibility to establish personalized milking, feeding, and resting schedules. Our study focused on investigating the short-term effects of transitioning milking permissions from every 4 (MP4) to 6 (MP6) hours on the 100th day of lactation on milking frequency, milk yields, and cow behavior. Twenty-four Holstein dairy cows were divided into control (maintaining a 4 h milking interval) and test groups (transitioning to a 6 h milking interval) and observed for 6 days. The analysis revealed that parity and treatment had no significant impact on milking frequency, milk/visit, or daily milk yield. However, multiparous cows spent more time inside the commitment pen, while test group cows exhibited more tail-swishing and displacement behavior, approached the AMS more frequently, and spent longer idle times. The interaction between parity and treatment influenced heart rate variability parameters, indicating increased stress in the test group cows. Additionally, the test group cows had greater total and daytime lying frequencies, suggesting short-term behavioral modifications. Despite no immediate impact on milk production, further research is recommended to assess the potential long-term effects on milk yield in AMS farms, considering the identified stress indicators short-term. [ABSTRACT FROM AUTHOR]

Missing data and class imbalance hinder the accurate prediction of rare events such as dairy mastitis. Resampling and imputation are employed to handle these problems. These methods are often used arbitrarily, despite their profound impact on prediction due to changes caused to the data structure. We hypothesize that their use affects the performance of ML models fitted to automated milking systems (AMSs) data for mastitis prediction. We compare three imputations—simple imputer (SI), multiple imputer (MICE) and linear interpolation (LI)—and three resampling techniques: Synthetic Minority Oversampling Technique (SMOTE), Support Vector Machine SMOTE (SVMSMOTE) and SMOTE with Edited Nearest Neighbors (SMOTEEN). The classifiers were logistic regression (LR), multilayer perceptron (MLP), decision tree (DT) and random forest (RF). We evaluated them with various metrics and compared models with the kappa score. A complete case analysis fitted the RF (0.78) better than other models, for which SI performed best. The DT, RF, and MLP performed better with SVMSMOTE. The RF, DT and MLP had the overall best performance, contributed by imputation or resampling (SMOTE and SVMSMOTE). We recommend carefully selecting resampling and imputation techniques and comparing them with complete cases before deciding on the preprocessing approach used to test AMS data with ML models. [ABSTRACT FROM AUTHOR]

The United States is predicted to experience an annual decline in milk production due to heat stress of 1.4 and 1.9 kg/day by the 2050s and 2080s, with economic losses of USD 1.7 billion and USD 2.2 billion, respectively, despite current cooling efforts implemented by the dairy industry. The ability of cattle to withstand heat (i.e., thermotolerance) can be influenced by physiological and behavioral factors, even though the factors contributing to thermoregulation are heritable, and cows vary in their behavioral repertoire. The current methods to gauge cow behaviors are lacking in precision and scalability. This paper presents an approach leveraging various machine learning (ML) (e.g., CNN and YOLOv8) and computer vision (e.g., Video Processing and Annotation) techniques aimed at quantifying key behavioral indicators, specifically drinking frequency and brush use- behaviors. These behaviors, while challenging to quantify using traditional methods, offer profound insights into the autonomic nervous system function and an individual cow's coping mechanisms under heat stress. The developed approach provides an opportunity to quantify these difficult-to-measure drinking and brush use behaviors of dairy cows milked in a robotic milking system. This approach will open up a better opportunity for ranchers to make informed decisions that could mitigate the adverse effects of heat stress. It will also expedite data collection regarding dairy cow behavioral phenotypes. Finally, the developed system is evaluated using different performance metrics, including classification accuracy. It is found that the YoloV8 and CNN models achieved a classification accuracy of 93% and 96% for object detection and classification, respectively. [ABSTRACT FROM AUTHOR]

Simple Summary: In the Americas, the Comarca Lagunera (CL), located in North-arid Mexico, concentrates one of the main dairy cattle hubs (>500,000 Holstein cows) managed under highly technified-industrial schemes. Dairy cows' nutrition is based on the use of total mixed rations; whereas feed rejection (i.e., 3–5%) has been observed, such feed-leftovers retain a high-pitched nutritional value. The CL also holds an emergent sheep industry, which exhibited the largest production value growth (i.e., >580%; 2010–2023). With that in mind and considering a circular economy perspective, we envisioned a research opportunity. Our working hypothesis states that a basal diet founded on such dairy cow feed-leftovers and aligned with short-term supplementation (i.e., 40 d) with Withania somnifera L. (Ashwagandha) will enhance some reproductive and behavioral outcomes in Black Belly rams. Such approach should bridge these two interesting animal production systems in the CL. Considering a circular economy perspective, this study evaluates the possible effect of targeted short-term supplementation with Withania somnifera L. (WS; Ashwagandha) on ram's seminal quality, socio-sexual behaviors, and blood constituents. Black Belly rams (n = 20) received a basal diet comprising feed-leftovers from dairy cows in the north-arid Mexico (i.e., Comarca Lagunera CL). The experimental units, with proven libido and fertility, were homogeneous in terms of age (3.41 ± 0.21 yr.), live weight (LW; 53.8 ± 3.3 kg), body condition (BC; 2.96 ± 0.01 units), initial sperm concentration (2387 ± 804 × 106), and viability (23.9 ± 15.6%). Rams were randomly assigned during the transition reproductive period (i.e., May to Jun; 25° NL) to three treatment groups: non-supplemented control group (CONT; n = 6), low WS-supplemented (LWS; i.e., 100 mg kg LW−1 d−1 × 40 d; n = 7), and high-WS-supplemented (HWS; i.e., 200 mg kg LW−1 d−1 × 40 d; n = 7). The basal leftover diet was offered twice daily (0700 and 1600 h); the experimental period (EP) lasted 47 d. No differences (p > 0.05) among treatments occurred regarding LW and BCS at the onset of the EP. Whereas the greater scrotal circumference (SCRC, cm) arose in the LWS and CONT rams, an increased ejaculated volume (VOLEJA, mL) occurred in the WS-rams. A total of 5/9 (i.e., 55%) appetitive and 3/3 (i.e., 100%) consummatory sexual behaviors favored (p < 0.05) the WS-rams, particularly the HWS rams, towards the final EP. The same was true (p < 0.05) regarding the hemogram variables white blood cell count (×109 cells L−1), hemoglobin concentration (g dL−1), and medium corpuscular volume (fL). This study, based on a rethink–reuse–reduce enquiry approach, enabled connectedness between two noteworthy animal systems in the CL: dairy cows and meat sheep schemes. Certainly, the use of dairy cow feed-leftovers aligned with the short-term supplementation with WS promoted enhanced testicular function, augmented seminal volume, and an increased sexual behavior in Black Belly rams in northern Mexico. Finally, while our research outcomes should enhance not only the resilience and sustainability of sheep production and the well-being of sheep-producers and their families, it may also embrace clinical translational applications. [ABSTRACT FROM AUTHOR]

Lameness is a crucial problem in dairy farming. It worsens the welfare of cattle, reduces the milk yield, and causes economic losses. The etiology of lameness is varied and the cattle's condition may be infectious or non-infectious. The aim of this research was to analyze the biocidal properties of silver (AgNPs), gold (AuNPs), and copper (CuNPs) nanoparticles against bacteria causing lameness in cattle. The isolated pathogens used were Aerococcus viridans, Corynebacterium freneyi, Corynebacterium xerosis, and Trueperella pyogenes. The tested concentrations of nanoparticles were 50, 25, 12.5, 6.25, 3.125, and 1.56 mg/L. The methods used included the isolation of pathogens using standard microbiological procedures and their identification using mass spectrometry, physicochemical analysis, transmission electron microscopy, and cytotoxicity tests. Studies have shown that AgNPs at 3.125 and 1.56 mg/L concentrations, and CuNPs at 25 and 12.5 mg/L concentrations, have strong biocidal properties, while AuNPs have the weakest antimicrobial properties. The very limited number of in vivo studies focusing on lameness prevention in cattle indicate that new solutions need to be developed. However, further studies are necessary to evaluate if nanoparticles (NPs) may, in the future, become components of innovative biocides used to prevent lameness in dairy cattle. [ABSTRACT FROM AUTHOR]

The endocannabinoid system (ECS) plays a crucial role in reproductive health, but its function in postpartum dairy cows remains poorly understood. This study investigated the expression patterns of ECS-related genes in the endometrium of postpartum dairy cows and their associations with endometrial health and the presence of fatty liver. Endometrial biopsies were collected from 22 Holstein Friesian cows at 4 and 7 weeks postpartum. Gene expression was analyzed using RT-qPCR, focusing on key ECS components including CNR2, MGLL, FAAH1, NAAA, NAPEPLD, PADI4 and PTGDS. The results reveal dynamic changes in ECS gene expression associated with endometritis and fatty liver. MGLL expression was significantly upregulated in cows with endometritis at 7 weeks postpartum, while NAAA expression was consistently downregulated in cows with fatty liver. CNR2 showed a time-dependent pattern in endometritis, and PTGDS expression was elevated in clinical endometritis at 4 weeks postpartum. The presence of fatty liver was associated with altered expression patterns of several ECS genes, suggesting a link between metabolic stress and endometrial ECS function. These findings indicate a potential role for the ECS in postpartum uterine health and recovery, offering new insights into the molecular mechanisms underlying reproductive disorders in dairy cows and paving the way for novel therapeutic approaches. [ABSTRACT FROM AUTHOR]

Rumination behavior in cattle can provide valuable information for monitoring health status and animal welfare, but continuous monitoring is essential to detect changes in rumination behavior. In a previous study validating the use of a respiration rate sensor equipped with a triaxial accelerometer, the regurgitation process was also clearly visible in the pressure and accelerometer data. The aim of the present study, therefore, was to measure the individual lengths of rumination cycles and to validate whether the sensor data showed the same number of regurgitations as those counted visually (video or direct observation). For this purpose, 19 Holstein Friesian cows equipped with a respiration rate sensor were observed for two years, with a focus on rumination behavior. The results showed a mean duration of 59.27 ± 9.01 s (mean ± SD) per rumination cycle and good agreement (sensitivity: 99.1–100%, specificity: 87.8–95%) between the two methods (sensor and visual observations). However, the frequency of data streaming (continuously or every 30 s) from the sensor to the data storage system strongly influenced the classification performance. In the future, an algorithm and a data cache will be integrated into the sensor to provide rumination time as an additional output. [ABSTRACT FROM AUTHOR]

Simple Summary: Lameness is an important welfare issue in dairy farming that is causing substantial economic losses. This study aims to determine the association of potential risk factors with farm-level lameness in German dairy herds, including cubicle design and cubicle bedding, feeding management, lameness assessment, claw health management, stocking density, and floor design. Risk factors were identified for all cows regardless of the number of calvings (primiparous and multiparous cows) and for first lactation cows separately. Results of the present study showed that larger cubicle width and deep bedded cubicles are associated with a lower risk of being lame. In farms feeding a total mixed ration, the risk of being lame was lower than in farms with other feeding routines (partial mixed ration or single components). For first lactation cows, the way and frequency of lameness assessment were associated with lameness. Many of the factors revealed by this study are related to cow comfort, especially the comfort when lying down. More attention is needed here to reduce lameness in German dairy cows. Six hundred fifty-nine farms in three regions of Germany (North: n = 240, East: n = 247, and South: n = 172) were included in the study, which aims at determining the association of management-related risk factors with farm-level lameness in German dairy herds. For each risk factor, a generalised linear regression model with negative binomial distribution and logit link was built. Results showed that cows housed in deep-bedded cubicles had a lower risk of being lame than cows housed in other cubicle types. A larger cubicle width was associated with a lower risk of being lame. Feeding a total mixed ration was associated with lower lameness prevalence (compared to feeding a partial mixed ration or single components). For first lactation cows, lameness assessment performed daily (compared to less than daily) and during other work tasks (compared to lameness assessment as a separate work task) were associated with lower risk for lameness. Finally, the present study provided evidence for crucial associations of management-related risk factors with lameness in German dairy cows, especially in the fields of cubicle design, feeding management, and lameness assessment. [ABSTRACT FROM AUTHOR]

Simple Summary: Managing cow diseases effectively remains a major challenge in dairy farming. Our study introduces a simple model for predicting dairy cow diseases. To develop this model, we used categorized data and Markov chains to select the best prediction model based on minimal error distance. The results show that our model is not only highly accurate and reliable but also easy to use, even in low-tech farms. Our methodological approach can capture various data structures in different volumes and qualities, demonstrating its versatility and adaptability to a wide range of herd sizes. This universal applicability enables us to evaluate entire herds, regardless of size. Furthermore, while each farm records diseases differently, our model can accommodate these variations. As such, this model may help dairy farmers manage herd health, predict antibiotic costs, and plan farming strategies. Modelling and predicting dairy cow diseases empowers farmers with valuable information for herd health management, thereby decreasing costs and increasing profits. For this purpose, predictive models were developed based on machine learning algorithms. However, machine-learning based approaches require the development of a specific model for each disease, and their consistency is limited by low farm data availability. To overcome this lack of complete and accurate data, we developed a predictive model based on discrete Homogeneous and Non-homogeneous Markov chains. After aggregating data into categories, we developed a method for defining the adequate number of Markov chain states. Subsequently, we selected the best prediction model through Chebyshev distance minimization. For 14 of 19 diseases, less than 15% maximum differences were measured between the last month of actual and predicted disease data. This model can be easily implemented in low-tech dairy farms to project costs with antibiotics and other treatments. Furthermore, the model's adaptability allows it to be extended to other disease types or conditions with minimal adjustments. Therefore, including this predictive model for dairy cow diseases in decision support systems may enhance herd health management and streamline the design of evidence-based farming strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Conformation traits have been a key breeding goal in dairy cattle for many years due to their relationship with animal productivity and other relevant characteristics. Therefore, the primary objectives of this study were to conduct genome-wide association studies (GWASs) for conformation traits and identify candidate genes and metabolic pathways associated with these traits in Brazilian Holstein cattle. Phenotypic, pedigree, and genomic (100 K SNP chip) data from 2339 Holstein animals raised across multiple Brazilian states were used for this study. Thirty-six significant SNPs were identified for five composite traits. These genomic markers overlap with candidate genes influencing biological processes such as myogenesis, adipogenesis, and angiogenesis. These findings contribute to unraveling the genetic background of conformation traits in Brazilian Holstein cattle. The linear conformation of animals exerts an influence on health, reproduction, production, and welfare, in addition to longevity, which directly affects the profitability of milk-producing farms. The objectives of this study were (1) to perform genome-wide association studies (GWASs) of conformation traits, namely the Rump, Feet and Legs, Mammary System, Dairy Strength, and Final Classification traits, and (2) to identify genes and related pathways involved in physiological processes associated with conformation traits in Brazilian Holstein cattle. Phenotypic and genotypic data from 2339 Holstein animals distributed across the states of Rio Grande do Sul, Paraná, São Paulo, and Minas Gerais were used. The genotypic data were obtained with a 100 K SNP marker panel. The single-step genome-wide association study (ssGWAS) method was employed in the analyses. Genes close to a significant SNP were identified in an interval of 100 kb up- and downstream using the Ensembl database available in the BioMart tool. The DAVID database was used to identify the main metabolic pathways and the STRING program was employed to create the gene regulatory network. In total, 36 significant SNPs were found on 15 chromosomes; 27 of these SNPs were linked to genes that may influence the traits studied. Fourteen genes most closely related to the studied traits were identified, as well as four genes that showed interactions in important metabolic pathways such as myogenesis, adipogenesis, and angiogenesis. Among the total genes, four were associated with myogenesis (TMOD2, TMOD3, CCND2, and CTBP2), three with angiogenesis (FGF23, FGF1, and SCG3), and four with adipogenesis and body size and development (C5H12orf4, CCND2, EMILIN1, and FGF6). These results contribute to a better understanding of the biological mechanisms underlying phenotypic variability in conformation traits in Brazilian Holstein cattle. [ABSTRACT FROM AUTHOR]

The study aims to explore the effects of composite microecological preparations on lactation performance, milk quality, and immune function of cows. The 160 Chinese Holstein cows with lactation days ranging from 240 to 280 days and 2-3 parity were selected and randomly divided into a control group and experimental groups A, B, and C. The control group cows were fed a basic diet, while experimental groups A, B, and C cows were fed a diet supplemented with 25, 50, and 75 g/(head·d) of composite microecological preparations (yeast culture+fungal enzyme+wall breaking yeast+probiotics) on top of the basic diet. The experimental period is 60 days. After the experiment, samples are taken to measure the milk production, milk quality, number of somatic cells in milk, antioxidant indicators, and immune function indicators of each group of cows, and the significance of the differences is compared and analyzed. The results showed that the average daily milk production, milk fat rate, and milk protein rate of the experimental group were significantly higher than those of the control group (P<0.05), and the number of somatic cells was significantly lower than that of the control group (P<0.05); the content of malondialdehyde (MDA) in serum samples was significantly lower than that in the control group (P<0.05), and the activities of catalase (CAT), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), immunoglobulin G (IgG), immunoglobulin A (IgA), γ-Interferon (γ-IFN) and interleukin-6 (IL-6) were significantly higher than those of the control group (P<0.05), and there was no significant difference in various indicators between experimental group B and experimental group C (P>0.05). Feeding each cow with a compound microecological preparation at a dose of 50 g/(head·d) could effectively improved lactation performance, improved milk quality, and enhanced immune function. [ABSTRACT FROM AUTHOR]

Simple Summary: The main objective of this study was to determine the influence of the recipient dairy cows' breed, lactation number, estrus condition, the type, location and volume of the corpus luteum (CL) and the time of year that the embryo transfer (ET) was performed on the pregnancy rates of a large, fresh in vitro fertilization–embryo transfer program for dairy cows in a commercial herd in China. Our results showed that heifers with a larger CL without liquid cavity in the center of the CL and ET in spring significantly enhanced the pregnancy rates in dairy cows under farm conditions in the northwest region of China. These results can help breeders to select the best recipient dairy cows and improve the efficiency of embryo transfer in China. The main objective of this study was to determine the influence of the recipient dairy cows' breed, lactation number, estrus condition, the type, location and volume of the corpus luteum (CL) and the time of year that the embryo transfer (ET) was performed on the pregnancy rates of a large, fresh in vitro fertilization–embryo transfer program for dairy cows in a commercial herd in China. The recipients were from a herd of dairy cows in Ningxia, a province in northwest China, and we statistically analyzed the data of 495 cows from 2021 to 2023. Cumulus oocyte complexes (COCS) were isolated from follicular fluid obtained through ovum pick-up (OPU) and oocytes were incubated 20–22 h for in vitro maturation (IVM). Embryos were obtained after 10–12 h of in vitro fertilization (IVF) and six days of in vitro culture (IVC). Embryos at the morula or blastocyst stage were transferred to randomly chosen recipients (n = 495). The influence of recipients' breed (Holstein or other), recipients' lactation number (heifers or cows), estrus type (natural or synchronized), CL type (homogeneous, CLhom or cavitary, CLcav), CL side (left or right), volume of the CL and season of transfer (spring, autumn or winter) on pregnancy rates were determined. The pregnancy rates were analyzed by binomial logistic regression with IBM SPSS statistics software, version 26. Pregnancy rates after ET to Holstein cows and other breeds were 43.49% and 42.68%, respectively (p > 0.05). Regarding age, pregnancy rates were 45.56% for heifers and 30.77% for cows (p < 0.05). Pregnancy rates following ET during natural and synchronized estrus were 44.41% and 41.5%, respectively (p > 0.05). Pregnancy rates with a left- or right-side CL were 40.18% and 45.65%, respectively (p > 0.05). The pregnancy rates achieved with a CLhom and CLcav were 44.44% and 39.68%, respectively (p < 0.05). The rates obtained in spring, autumn and winter were 49.26%, 46.02% and 34.64%, respectively (p < 0.05). Moreover, it was found that pregnancy rates were higher in recipients with a CL volume measuring greater than 10 cm3 compared with those with a CL volume measuring less than 10 cm3 (p < 0.05). The comparisons showed that recipients' breed, estrus type or side of the CL had no effect, but the recipients' lactation number, ET season and the type and volume of the CL have significant effects on pregnancy rates during ET. [ABSTRACT FROM AUTHOR]

Simple Summary: This study proposes an automatic classification system for determining body condition score in dairy cows using a deep learning architecture. An original dataset was created by categorizing images of different breeds from different farms into five body condition score classes: Emaciated, Poor, Good, Fat, and Obese. In the experimental analysis, the proposed deep learning model accurately classified 102 out of 126 cow images in the test set, achieving an average accuracy of 0.81 for all classes in Holstein and Simmental cows and an average area under the precision–recall curve of 0.87. The proposed body condition score classification system can help to accurately monitor rapid declines in body condition in dairy cows and serve as a tool for production decision-makers to reduce negative energy balance during early lactation. Body condition score (BCS) is a common tool used to assess the welfare of dairy cows and is based on scoring animals according to their external appearance. If the BCS of dairy cows deviates from the required value, it can lead to diseases caused by metabolic problems in the animal, increased medication costs, low productivity, and even the loss of dairy cows. BCS scores for dairy cows on farms are mostly determined by observation based on expert knowledge and experience. This study proposes an automatic classification system for BCS determination in dairy cows using the YOLOv8x deep learning architecture. In this study, firstly, an original dataset was prepared by dividing the BCS scale into five different classes of Emaciated, Poor, Good, Fat, and Obese for images of Holstein and Simmental cow breeds collected from different farms. In the experimental analyses performed on the dataset prepared in this study, the BCS values of 102 out of a total of 126 cow images in the test set were correctly classified using the proposed YOLOv8x deep learning architecture. Furthermore, an average accuracy of 0.81 was achieved for all BCS classes in Holstein and Simmental cows. In addition, the average area under the precision–recall curve was 0.87. In conclusion, the BCS classification system for dairy cows proposed in this study may allow for the accurate observation of animals with rapid declines in body condition. In addition, the BCS classification system can be used as a tool for production decision-makers in early lactation to reduce the negative energy balance. [ABSTRACT FROM AUTHOR]

Simple Summary: Cervical mucus plays a crucial role in the fertilization process, not only providing energy for sperm but also forming a barrier to block sperm. This experiment investigated the microstructure of cervical mucus and its impact on sperm permeability during the proestrus, estrus, and metestrus in dairy cows. The cervical mucus of cows is mainly composed of four types, and as the estrous cycle changes, the proportion of different types of cervical mucus also changes. There are differences in the microstructure among the four types of cervical mucus. The ability of cervical mucus to allow sperm penetration varies during different estrous phases. These findings provide data supporting the study of cervical mucus. Cervical mucus not only provides energy for sperm but also forms a barrier to block sperm. This paper aims to study the microstructure of cervical mucus in dairy cows during the proestrus, estrus, and metestrus and its effect on sperm permeability. The experiment collected cervical mucus from 60 Holstein cows during these phases, then observed the different shapes of the mucus after crystallization, classified the mucus, and analyzed its proportions. Scanning electron microscopy was used to observe the ultrastructure of the cervical mucus and measure the micro-pore sizes, followed by sperm permeability tests using mucus from different estrous stages and counting the number of permeated sperm. The results indicate that cervical mucus from cows in different estrous phases includes four types (L, S, P, G), with each type constituting a different proportion. During the proestrus, the L type was significantly more prevalent than the other types (p < 0.05); during estrus, the S type was significantly more prevalent than the other types (p < 0.05); and during the metestrus, the p type was significantly more prevalent than the other types (p < 0.05). The micro-pore sizes of the same type of cervical mucus did not show significant differences across different estrous phases (p > 0.05). However, within the same estrous phase, there were significant differences in the micro-pore sizes among the four types (p < 0.05). The number of sperm that permeated the cervical mucus during estrus and metestrus was significantly higher than during the proestrus (p < 0.05). This study provides data support for the research on cervical mucus in dairy cows. [ABSTRACT FROM AUTHOR]

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This study investigates the impact of propylene glycol (PRG) on ketotic cows, focusing on alleviating oxidative stress and enhancing immunity through modulating amino acid and lipid metabolism. Ketosis, a prevalent metabolic disease in dairy cows, negatively affects productivity and health. PRG, known for its gluconeogenic properties, was administered to cows with ketosis daily for three days and compared to an untreated group. Serum samples were taken to measure the biochemical parameters, and metabolomic and lipidomic analyses were performed with ultra-high-performance liquid chromatography–mass spectrometry. The results showed significant reductions in serum non-esterified fatty acids, beta-hydroxybutyrate, and C-reactive protein levels, alongside increased glucose, anti-inflammatory factor interleukin-10, superoxide dismutase, and glutathione peroxidase activities. Metabolomic and lipidomic analyses revealed significant alterations, including increased levels of glucogenic amino acids like glutamate and proline, and decreased levels of ceramide species. A pathway analysis indicated that PRG affects multiple metabolic pathways, including alanine, aspartate, glutamate metabolism, and sphingolipid metabolism. These findings suggest that PRG not only mitigates oxidative stress, but also enhances immune function by restoring metabolic homeostasis. This study provides valuable insights into the biochemical mechanisms underlying PRG's therapeutic effects, offering potential strategies for the effective management and treatment of ketosis in dairy cows. [ABSTRACT FROM AUTHOR]

The objective of this bovine peripheral blood study was a comparative assessment of the phagocytic activity of neutrophils and monocytes and of the intracellular killing capacity of neutrophils from cows given no probiotic and from cows which were administered a probiotic consisting of Saccharomyces cerevisiae, Lactobacillus acidophilus, Lactobacillus plantarum and Rhodopseudomonas palustris. These activity types were compared during different lactation periods. A cohort of 20 pregnant dairy cows was divided into two groups of 10. The experimental group consisted of cows fed a ration supplemented with probiotics, and the control group consisted of cows fed an unsupplemented ration. Blood was drawn six times: 7 days before dry off, 14 days before parturition, and 7, 21, 60 and 90 days postpartum (DPP). The phagocytic activity of neutrophils and monocytes and the oxidative burst activity of neutrophils were determined by flow cytometry in the peripheral blood of all examined cows. Phagocytosis testing revealed increased percentages of phagocytic neutrophils and monocytes in the experimental group at 21, 60 and 90 DPP (P-value < 0.01). The mean fluorescence intensity (MFI) values for neutrophils and monocytes were higher on all days of the study (P-value < 0.01). In oxidative burst testing, the percentages of detected neutrophils and their MFI were increased in the experimental group on all days (P-value < 0.01). The use of probiotics supported dairy cows' immunity throughout the whole experiment. Probiotic supplementation may limit the occurrence of infectious diseases in these animals. [ABSTRACT FROM AUTHOR]

ABSTRACT: In modern breeding systems, cows are subjected to many stress factors. Animals fed a high-grain diet may have a decreased rumen pH, which would lead to subacute ruminal acidosis syndrome. The aim of this study was to investigate the evolution of microbial community composition in cows undergoing a dietary stress challenge. Twelve cows were subjected to a challenge period that consisted of a rapid change of ration, from a normal (45.4:54.6 forage:concentrate) to a high-grain content diet (24.8:75.2 forage:concentrate) to induce subacute ruminal acidosis. Individual rumen fluid content samples were collected before (T0) and during the challenge (T3, T14, T28). The DNA from rumen contents was extracted, purified, and sequenced to evaluate bacterial populations, and sequencing was performed on Illumina MiSeq. The effect of animal conditions on rumen microbial community was quantified through a linear mixed model. The acidogenic diet created 2 main clusters: ruminal hypomotility (RH) and milk fat depression (MFD). The microbial composition did not differ in T0 between the 2 groups, whereas during the challenge Ruminococcus spp., Treponema spp., Methanobrevibacter spp., and Methanosphaera spp. concentrations increased in RH cows; and Succinivibrio spp. and Butyrivibrio spp. concentrations increased in MFD cows. Prevotella spp. and Ruminococcus spp. were negatively correlated, whereas the Christenellaceae family was positively correlated with both Methanobrevibacter spp. and Methanosphaera spp. Moreover, the same diet affected cows' microbiota composition differently, underlying the impact of the host effect. Other studies are necessary to deepen the relationship between microbiota composition and host.

ABSTRACT: The CellCheck dry cow consult (DCC) was developed by the CellCheck Technical Working Group to enable farmers to engage with their nominated veterinarian to develop farm-specific selective dry cow therapy (SDCT) plans, where appropriate. This study evaluated the effect of the DCC on farmer decision-making around dry cow therapy, and the udder health effects of implementing SDCT, in study herds over the 2019 and 2020 dry periods. The DCC was a 3-h consult, delivered and funded as part of the Targeted Advisory Service on Animal Health. Herds that completed a DCC were invited to register for a dry cow review the following year. The combined dataset for analysis across both years comprised 439 herds and 25,357 cows. Herd size ranged from 25 to 800. The median SCC of cows dried off with teat sealant only was 47,000 cells/mL before drying off in 2019 and 48,000 cells/mL at first milk recording in 2020, and 43,000 cells/mL before drying off in 2020 and 39,000 cells/mL at first milking recording in 2021. Following both the 2019 and 2020 dry periods, cows tended to converge toward a similar median SCC early in the following lactation, irrespective of prior dry cow treatment strategy. The uptake of SDCT was greater in review herds, with 21% of cows receiving teat sealant only in 2020, compared with 16.3% of cows in herds participating in a consult for the first time in 2020. At an individual cow level, in both years dry period new infection rate (NIR) was approximately 2.7% higher for cows treated with teat sealant only, than for those treated with both dry cow antibiotic tubes and teat sealant, and 1.2% higher than cows treated with antibiotic only. Regardless of treatment, a significant association was detectable between increasing parity and the risk of a dry period new infection. Increasing herd size had a significant effect on the risk of dry period NIR. At a herd level, no significant increase in NIR occurred when SDCT was used compared with herds where blanket dry cow therapy was used. Though not without risk, SDCT can be successfully implemented in Irish herds; however, constant attention to hygiene and management is essential. Despite the challenges, facilitating continued farmer education and engagement with professional guidance will be important.

ABSTRACT: Mycoplasmosis (due to infection with Mycoplasma bovis) is a serious disease of beef and dairy cattle that can adversely affect health, welfare, and productivity. Mycoplasmosis can lead to a range of often severe, clinical presentations. Mycoplasma bovis infection can present either clinically or subclinically, with the potential for recrudescence of shedding in association with stressful periods. Infection can be maintained within herds because of intermittent shedding. Mycoplasma bovis is recognized as poorly responsive to treatment, which presents a major challenge for control in infected herds. Given this, particular focus is needed on biosecurity measures to prevent introduction into uninfected herds in the first place. A robust and reliable laboratory test for surveillance is important for both herd-level prevention and control. The objective of this study was to estimate the sensitivity (Se) and specificity (Sp) of 3 diagnostic tests (1 PCR and 2 ELISA tests) on bulk tank milk (BTM), for the herd-level detection of M. bovis using Bayesian latent class analysis (BLCA). In autumn 2018, BTM samples from 11,807 herds, covering the majority of the main dairy regions in Ireland had been submitted to the Department of Agriculture testing laboratory for routine surveillance and were made available for study. A stratified random sample approach was used to select a cohort of herds for testing from this larger sample set. A final study population of 728 herds had BTM samples analyzed using a Bio-X ELISA (ELISA 1), an IDvet ELISA (ELISA 2) and a PCR test. A BLCA was conducted to estimate the Se and Sp of the 3 diagnostic tests applied to BTM for the detection of herd-level infection. An overall latent class analysis was conducted on all herds within a single population (a 3-test, 1-population model). The herds were also split into 2 populations based on herd size (small herds had

ABSTRACT: The nutritional components and quality of milk are influenced by the rumen microbiota and its metabolites at different lactation stages. Hence, rumen fluid and milk samples from 6 dairy cows fed the same diet were collected during peak lactation, early mid-lactation, and later mid-lactation. Untargeted metabolomics and 16S rRNA sequencing were applied for analyzing milk and rumen metabolites, as well as rumen microbial composition, respectively. The levels of lipid-related metabolites, l-glutamate, glucose-1-phosphate, and acetylphosphate in milk exhibited lactation-dependent attenuation. Maltol, N-acetyl-d-glucosamine, and choline, which are associated with milk flavor or coagulation properties, as well as l-valine, lansioside A, clitocine, and ginsenoside La, increased significantly in early mid-lactation and later mid-lactation, especially in later mid-lactation. The obvious increase in rumen microbial diversities (ACE and Shannon indices) were observed in early mid-lactation compared with peak lactation. Twenty-one differential bacterial genera of the rumen were identified, with Succinivibrionaceae_UCG-001, Candidatus Saccharimonas, Fibrobacter, and SP3-e08 being significantly enriched in peak lactation. Rikenellaceae_RC9_gut_group, Eubacterium_ruminantium_group, Lachnospira, Butyrivibrio, Eubacterium_hallii_group, and Schwartzia were most significantly enriched in early mid-lactation. In comparison, only 2 bacteria (unclassified_f__Prevotellaceae and Prevotellaceae_UCG-001) were enriched in later mid-lactation. For rumen metabolites, LysoPE(16:0), l-glutamate, and l-tyrosine had higher levels in peak lactation, whereas PE(17:0/0:0), PE(16:0/0:0), PS(18:1(9Z)/0:0), l-phenylalanine, dulcitol, 2-(methoxymethyl)furan, and 3-phenylpropyl acetate showed higher levels in early mid-lactation and later mid-lactation. Multiomics-integrated analysis revealed that a greater abundance of Fibrobacter contributed to phospholipid content in milk by increasing ruminal acetate, l-glutamate, and LysoPE(16:0). Prevotellaceae_UCG-001 and unclassified_f_Prevotellaceae provide substrates for milk metabolites of the same category by increasing ruminal l-phenylalanine and dulcitol contents. These results demonstrated that milk metabolomic fingerprints and critical functional metabolites during lactation, and the key bacteria in rumen related to them. These findings provide new insights into the development of functional dairy products.

Abstract Bovine mastitis is one of the main inflammatory diseases that can affect the udder during lactation. Somatic cell counts and sometimes microbiological tests are routinely adopted during monitoring diagnostics in dairy herds. However, subclinical mastitis is challenging to identify, reducing the possibility of early treatments. The main aim of this study was to investigate the miRNome profile of extracellular vesicles isolated from milk as potential biomarkers of subclinical mastitis. Milk samples were collected from a total of 60 dairy cows during routine monitoring tests. Small RNA sequencing technology was applied to extracellular vesicles of milk samples collected from cows classified according to the somatic cell count to identify differences in the miRNome between mastitic and healthy cows. A total of 1997 miRNAs were differentially expressed between both groups. Among them, 68 miRNAs whose FDRs were

Missing data and class imbalance hinder the accurate prediction of rare events such as dairy mastitis. Resampling and imputation are employed to handle these problems. These methods are often used arbitrarily, despite their profound impact on prediction due to changes caused to the data structure. We hypothesize that their use affects the performance of ML models fitted to automated milking systems (AMSs) data for mastitis prediction. We compare three imputations—simple imputer (SI), multiple imputer (MICE) and linear interpolation (LI)—and three resampling techniques: Synthetic Minority Oversampling Technique (SMOTE), Support Vector Machine SMOTE (SVMSMOTE) and SMOTE with Edited Nearest Neighbors (SMOTEEN). The classifiers were logistic regression (LR), multilayer perceptron (MLP), decision tree (DT) and random forest (RF). We evaluated them with various metrics and compared models with the kappa score. A complete case analysis fitted the RF (0.78) better than other models, for which SI performed best. The DT, RF, and MLP performed better with SVMSMOTE. The RF, DT and MLP had the overall best performance, contributed by imputation or resampling (SMOTE and SVMSMOTE). We recommend carefully selecting resampling and imputation techniques and comparing them with complete cases before deciding on the preprocessing approach used to test AMS data with ML models.

This study aims to contribute valuable insights to readers and serve as a reference for dairy farmers looking to enhance their operations. By examining the prevalence and risk factors associated with repeat breeder syndrome in dairy cows within the Village Unit Cooperation (KUD) Bebarengan Anggayuh Tentrem Urip, Batu City, East Java Province, this study aims to aid in preventing such occurrences and ultimately improve dairy cow productivity. The survey method was employed, utilizing data sourced from cooperative and farmer records, as well as observations, interviews, and questionnaire responses. Analysis revealed that out of 50 farmers owning a total of 281 cows, 30 farmers possessed a combined total of 58 dairy cows classified as repeat breeders. Consequently, the prevalence rate of repeat breeders among farmers was found to be 20.64%. Descriptive analysis was conducted on the collected data, with additional SPSS Chi-Square (X²) analysis performed to identify risk factors associated with repeat breeders. These risk factors include breeder experience, knowledge of reproduction and estrus phases, communication with artificial inseminators and veterinarians, housing conditions, as well as factors related to livestock feed and water.

The study examined effects of thyroid manipulation with propylthiouracil (PTU) on the metabolic adaptability of transitional dairy cows to early lactation. The study included 30 primiparous Holstein-Friesian cows, which were divided into two groups: PTU+ (n = 15; received orally 4 mg/kg PTU during 20 days before expected calving) and PTU− (n = 15; did not receive orally PTU). Blood was sampled from each cow consecutively from − 20, − 17, − 13, − 5, − 4, − 3, − 2, and − 1 days before the expected term of calving, calving day (0), and + 1, + 2, + 3, + 4, + 5, + 10, + 15, + 30 and + 60 days after the calving to measure thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), insulin, glucose, beta-hydroxybutyrate (BHB), bilirubin, total protein and albumin concentrations. Liver samples were biopsied at −7 ± 2 and +7 day relative to calving from both groups of cows to determine deiodinase (DIO) expressions and fat and glycogen content. Additionally, milk yield was monitored during the first 60 days of lactation. PTU successfully induced thyroid suppression by significantly reducing T3 and T4 concentrations and hepatic DIO1 expressions and caused PTU+ cows to have significantly higher insulin and glucose concentration in the precalving period. After calving, PTU+ cows had higher insulin and glucose concentration, liver glycogen content and overall milk production, lower BHB concentration, BCS loss, and liver fat deposits. Accordingly, cows treated with PTU have a more favourable energy balance and metabolic adaptation to early lactation.

The purpose of this study was to determine the effect of mulberry (Morus alba L.) leaf (ML) supplementation on the productivity, blood metabolism, rumen fermentation characteristics and rumen microbial population in lactating dairy cows. Twelve healthy multiparous Holstein dairy cows (initial characteristics: body weight = 442.83 ± 86.87 kg; milk yield = 12.55 ± 1.91 kg/d; days in milk = 150.0 ± 47.0 d) were randomly allocated to two treatment groups of six cows each. The cows were fed two different diets: a control diet (basal diet without ML; CTRL group) and a ML-supplemented diet (basal diet + 300 g ML; ML group). The trial lasted for a total of 28 d after an adjustment period of 14 d. The total rumen volatile fatty acid (VFA) levels (p = .063) and the propionate level (p

The United States is predicted to experience an annual decline in milk production due to heat stress of 1.4 and 1.9 kg/day by the 2050s and 2080s, with economic losses of USD 1.7 billion and USD 2.2 billion, respectively, despite current cooling efforts implemented by the dairy industry. The ability of cattle to withstand heat (i.e., thermotolerance) can be influenced by physiological and behavioral factors, even though the factors contributing to thermoregulation are heritable, and cows vary in their behavioral repertoire. The current methods to gauge cow behaviors are lacking in precision and scalability. This paper presents an approach leveraging various machine learning (ML) (e.g., CNN and YOLOv8) and computer vision (e.g., Video Processing and Annotation) techniques aimed at quantifying key behavioral indicators, specifically drinking frequency and brush use- behaviors. These behaviors, while challenging to quantify using traditional methods, offer profound insights into the autonomic nervous system function and an individual cow’s coping mechanisms under heat stress. The developed approach provides an opportunity to quantify these difficult-to-measure drinking and brush use behaviors of dairy cows milked in a robotic milking system. This approach will open up a better opportunity for ranchers to make informed decisions that could mitigate the adverse effects of heat stress. It will also expedite data collection regarding dairy cow behavioral phenotypes. Finally, the developed system is evaluated using different performance metrics, including classification accuracy. It is found that the YoloV8 and CNN models achieved a classification accuracy of 93% and 96% for object detection and classification, respectively.

Abstract Background As cows transition from pregnancy to lactation, free fatty acids (FFA) are mobilized from adipose tissues (AT) through lipolysis to counter energy deficits. In clinically healthy cows, lipolysis intensity is reduced throughout lactation; however, if FFA release exceeds tissue demands or the liver’s metabolic capacity, lipid byproducts accumulate, increasing cows’ risk of metabolic and infectious disease. Endocannabinoids (eCBs) and their congeners, N-acylethanolamines (NAEs), are lipid-based compounds that modulate metabolism and inflammation. Their synthesis and release depend upon the availability of FFA precursors and the abundance of synthesizing and degrading enzymes and transporters. Therefore, we hypothesized that eCB production and transcription of endocannabinoid system components are modulated by lipolysis pathways in adipocytes. To test this hypothesis, we stimulated canonical (isoproterenol, 1 µmol/L; ISO) and inflammatory (lipopolysaccharide, 1 µg/mL; LPS) lipolysis pathways in adipocytes isolated from the AT of 5 Holstein dairy cows. Following, we assessed lipolysis intensity, adipocytes’ release of eCBs, and transcription of endocannabinoid system components. Results We found that ISO and LPS stimulated lipolysis at comparable intensities. Exposure to either treatment tended to elevate the release of eCBs and NAEs by cultured adipocytes; however, specific eCBs and NAEs and the transcriptional profiles differed by treatment. On one hand, ISO enhanced adipocytes’ release of 2-arachidonoylglycerol (2-AG) but reduced NAE production. Notably, ISO enhanced the cells’ expression of enzymes associated with 2-AG biosynthesis (INPP5F, GDPD5, GPAT4), transport (CD36), and adipogenesis (PPARG). Conversely, LPS enhanced adipocytes’ synthesis and release of N-arachidonoylethanolamide (AEA). This change coincided with enhanced transcription of the NAE-biosynthesizing enzyme, PTPN22, and adipocytes’ transcription of genes related to eCB degradation (PTGS2, MGLL, CYP27B1). Furthermore, LPS enhanced adipocytes’ transcription of eCB and NAE transporters (HSPA1A, SCP2) and the expression of the anti-adipogenic ion channel, TRPV3. Conclusions Our data provide evidence for distinct modulatory roles of canonical and inflammatory lipolysis pathways over eCB release and transcriptional regulation of biosynthesis, degradation, transport, and ECS signaling in cows’ adipocytes. Based on our findings, we conclude that, within adipocytes, eCB production and ECS component expression are, at least in part, mediated by lipolysis in a pathway-dependent manner. These findings contribute to a deeper understanding of the molecular mechanisms underlying metabolic regulation in dairy cows’ AT, with potential implications for prevention and treatment of inflammatory and metabolic disorders. Graphical Abstract

The widespread adoption of automatic milking systems (AMS) in the United States has afforded dairy cows the flexibility to establish personalized milking, feeding, and resting schedules. Our study focused on investigating the short-term effects of transitioning milking permissions from every 4 (MP4) to 6 (MP6) hours on the 100th day of lactation on milking frequency, milk yields, and cow behavior. Twenty-four Holstein dairy cows were divided into control (maintaining a 4 h milking interval) and test groups (transitioning to a 6 h milking interval) and observed for 6 days. The analysis revealed that parity and treatment had no significant impact on milking frequency, milk/visit, or daily milk yield. However, multiparous cows spent more time inside the commitment pen, while test group cows exhibited more tail-swishing and displacement behavior, approached the AMS more frequently, and spent longer idle times. The interaction between parity and treatment influenced heart rate variability parameters, indicating increased stress in the test group cows. Additionally, the test group cows had greater total and daytime lying frequencies, suggesting short-term behavioral modifications. Despite no immediate impact on milk production, further research is recommended to assess the potential long-term effects on milk yield in AMS farms, considering the identified stress indicators short-term.

The infertility of cows and heifers has been the most pressing problem in the livestock sector. The genitals and mammary gland have an increased functional load associated with pregnancy, childbirth, and lactation. The purpose of this study was to determine the prevalence of symptoms of chronic irreversible infertility in Ayrshire cows culled as a result of multiple artificial inseminations. The study employed analytical, structural-comparative, and statistical methods, as well as a modified differential palpation diagnosis of the clinical state of the reproductive organs in the ovary+oviduct area with lateral localisation was consistently applied in two stages. The findings of the study showed that cows with in vivo diagnosed symptoms of chronic adherent salpingitis and ovosalpingitis (52.17%), i.e., irreversible form of infertility, had significantly higher (+28.05%; P < 0.01) milk production and better lactation compared to those without these pathologies. Furthermore, in the group of cows culled due to numerous ineffective inseminations, related gonadopathies were detected: from 4.35% to 10.87% of ovarian hypotrophy, 4.35% of gonadal sclerosis symptoms and 17.39% of cystic follicular degeneration cases. In 73.91% of females, the presence of sexual cyclicity with unchanged ovarian function in the follicular phase and in 84.78% – in the luteal phase of the cycle was established. The use of differential palpation diagnostics in production conditions allows in vivo predicting the tendency to loss of genetic resources (the ability of cow ovaries to maintain generative and secretory functions) in highly productive cows due to chronic inflammatory gynecological pathologies, which will contribute to the improvement of drug and biotechnological schemes of therapeutic measures for the prevention of infertility in the dairy herd

Objective There is a strong relationship between the content of beneficial fatty acids in milk and milk fat metabolic activity in the mammary gland. To improve milk quality, it is therefore necessary to study fatty acid metabolism in bovine mammary gland tissue. In adipose tissue, peroxisome proliferator-activated receptor gamma (PPARG), the core transcription factor, regulates the fatty acid metabolism gene network and determines fatty acid deposition. However, its regulatory effects on mammary gland fatty acid metabolism during lactation have rarely been reported. Methods Transcriptome sequencing was performed during the prelactation period and the peak lactation period to examine mRNA expression. The significant upregulation of PPARG drew our attention and led us to conduct further research. Results According to bioinformatics prediction, dual-luciferase reporter system detection, real-time quantitative reverse transcription polymerase chain reaction and Western blotting, miR-130a and miR-130b could directly target PPARG and inhibit its expression. Furthermore, triglyceride and oil red O staining proved that miR-130a and miR-130b inhibited milk fat metabolism in bovine mammary epithelial cells (BMECs), while PPARG promoted this metabolism. In addition, we also found that the coexpression of miR-130a and miR-130b significantly enhanced their ability to regulate milk fat metabolism. Conclusion In conclusion, our findings indicated that miR-130a and miR-130b could target and repress PPARG and that they also have a functional superposition effect. miR-130a and miR-130b seem to synergistically regulate lipid catabolism via the control of PPARG in BMECs. In the long-term, these findings might be helpful in developing practical means to improve high-quality milk.

Objective This study evaluated the effects of high moisture ear corn (HMEC) on production performance, milk fatty acid composition, serum antioxidant status, and immunity in primiparous dairy cows. Methods A total of 45 healthy primiparous Holstein cows (36.50±4.30 kg of milk/d, 201±9.00 lactating days in milk) were sorted into 3 groups: control group (CG, n = 15); 50% HMEC (replacing 50% steam-flaked corn with HMEC, n = 15); and 100% HMEC (replacing steam-flaked corn with HMEC, n = 15) on an equal dry matter (DM) basis. The study consisted of adaptation period of 14 days, followed by a formal period of 60 days. Feed intake and milk yield were recorded daily. Milk and blood samples were collected on 1, 30, and 60 d of the experimental period. Results The 50% HMEC group and 100% HMEC group significantly increased (p

ABSTRACT: The objectives of this retrospective observational study were to investigate the association between BCS at 21 d before calving with prepartum and postpartum DMI, energy balance (EB), and milk yield. Data from 427 multigravid cows from 11 different experiments conducted at the University of Florida (Gainesville, FL) were used. Cows were classified according to their BCS at 21 d before calving as fat (BCS ≥ 4.00; n = 83), moderate (BCS = 3.25–3.75; n = 287), and thin (BCS ≤ 3.00; n = 57). Daily DMI from −21 to −1 and from +1 to +28 DIM was individually recorded. Energy balance was calculated as the difference between net energy for lactation consumed and required. Dry matter intake in fat cows was lower than that in moderate and thin cows both prepartum (fat = 9.97 ± 0.21, moderate = 11.15 ± 0.14, and thin = 11.92 ± 0.22 kg/d) and postpartum (fat = 14.35 ± 0.49, moderate = 15.47 ± 0.38, and thin = 16.09 ± 0.47 kg/d). Dry matter intake was also lower for moderate cows compared with thin cows prepartum, but not postpartum. Energy balance in fat cows was lower than in moderate and thin cows both prepartum (fat = −4.16 ± 0.61, moderate = −1.20 ± 0.56, and thin = 0.88 ± 0.62 Mcal/d) and postpartum (fat = −12.77 ± 0.50, moderate = −10.13 ± 0.29, and thin = −6.14 ± 0.51 Mcal/d). Energy balance was also lower for moderate cows compared with thin cows both prepartum and postpartum. There was a quadratic association between BCS at 21 d before calving and milk yield. Increasing BCS from 2.5 to 3.5 was associated with an increase in daily milk yield of 6.0 kg and 28 d cumulative milk of 147 kg. Increasing BCS from 3.5 to 4.5 was associated with a decrease in daily milk yield of 4.4 kg and 28 d cumulative milk of 116 kg. In summary, a moderate BCS at 21 d before calving was associated with intermediate DMI and EB pre- and postpartum but greater milk yield compared with thinner and fatter cows. Our findings indicate that a moderate BCS is ideal for ensuring a successful lactation.

ABSTRACT: Lysine is one of the limiting AA in the diets of dairy cows and is typically fed as rumen-protected Lys (RPL). We hypothesized that supplementation of RPL during the postpartum period would improve the productive performance in dairy cows. Objectives were to use meta-analytic methods to explore the effects of feeding RPL on performance and blood AA profile in lactating dairy cows. An additional objective was to identify an optimal concentration (%) of Lys in MP (LYSMP) and determine if responses to LYSMP were associated with the concentration (%) of Met in MP (METMP). The literature was systematically reviewed, and 13 experiments, comprising 40 treatment means and 594 lactating cows, were included in the meta-analysis. All experiments had a nonsupplemental control (CON; n = 17 treatment means), or a group supplemented with RPL (n = 23 treatment means). Cows supplemented with RPL were supplied additionally with a mean (±standard deviation) 19.3 ± 10.3 g/d metabolizable Lys (5.1–40.6 g/d). Meta-analytical statistics were used to estimate the weighted mean difference in STATA. Mixed models were fitted to the data to investigate the linear and quadratic effects of LYSMP, METMP, and interactions between LYSMP and METMP. All models included the random effect of experiment and weighting by the inverse of the SE of the means squared. Cows that began receiving RPL in early lactation (≤90 DIM) or for an extended duration (≥70 DIM) produced 1.51 kg/d more milk compared with CON cows. Increasing digestible LYSMP from 6.5% to 8.5% linearly increased yields of milk, FCM, ECM, and milk fat by 1.8, 2.5, 2.4, and 0.10 kg/d, respectively, and tended to increase milk protein yield and body weight gain by 0.07 and 0.09 kg/d, respectively, without a concurrent increase in DMI. Interactions between the linear effects of LYSMP and METMP were observed for FCM/DMI or ECM/DMI. In a diet with low METMP (e.g., 1.82% of MP), a digestible supply of 7.40% LYSMP would result in 1.46 and 1.47 kg/kg FCM/DMI or ECM/DMI, respectively; however, with high digestible METMP (e.g., 2.91% of MP), supplying 7.40% of digestible LYSMP would result in 1.68 and 1.62 kg/kg FCM/DMI or ECM/DMI, respectively. Increasing digestible LYSMP from 6.5% to 8.5% linearly increased blood concentrations of Lys by 16.6 µM, whereas blood concentrations of Met and Ala decreased by 4.6 and 6.0 µM, respectively. Nevertheless, an interaction was also observed between LYSMP and METMP for blood concentrations of total EAA because as METMP increased, the positive response to LYSMP on total EAA was also increased, suggesting a competitive mobilization of AA and their utilization in various body tissues. Only 4 out of the 13 experiments in this meta-analysis involved primiparous cows; thus, insufficient data were available to understand the role of supplemental RPL in primiparous cows. Collectively, feeding RPL improved productive performance, and the increments were maximized up to 9.25% of LYSMP in multiparous dairy cows.

ABSTRACT: The intestinal microbiota plays a pivotal role in digestive processes and maintains gut health and intestinal homeostasis. These functions may be compromised by increased environmental heat, which in turn reduces feed intake and gut integrity and activates the intestinal immune system. It remains unknown whether high ambient temperatures, which cause heat stress (HS) in dairy cows, disturb the eubiosis of the microbial community, and if so, to which extent the reduction in feed intake and the impairment of circulating and intestinal metabolites account for the alterations of the jejunal microbiota. To address these questions, jejunal digesta, mucosa, and plasma samples were collected from cows exposed to heat stress (HS; 28°C, temperature-humidity index [THI] = 76, n = 10), control conditions (CON; 16°C, THI = 60, n = 10), or pair-fed (PF; 16°C, THI = 60, n = 10) for 7 d. Digesta fluids were examined for pH, acetate, nonesterified fatty acids (NEFA), glucose, and lactate, and plasma samples were analyzed for glucose, lactate, BHB, triglycerides, NEFA, creatinine, and urea. The microbiota of the digesta and mucosa samples were analyzed by 16S rRNA sequencing. The α-diversity was higher in mucosa than digesta but was not affected by high ambient temperatures. However, the mucosa-associated microbiota appeared more responsive to ambient heat than the digesta microbiome. The adaptive responses under HS conditions comprised an increased mucosal abundance of Bifidobacteriaceae, Succinivibrionaceae UCG-001, Clostridia and Lactobacillus. In the digesta, HS has exerted effects on microbial abundance of Colidextribacter, and Lachnospiraceae UCG-008. Several correlations between plasma or intestinal metabolites and microbiota were elucidated, including Methanobacteriaceae correlating positively with plasma BHB and digesta glucose concentrations. Moreover, the reduction in feed intake during HS had non-negligible effects on microbial diversity and the abundance of certain taxa, underpinning the importance of nutrient supply on maintaining intestinal homeostasis.

Background: High-yielding dairy cows are commonly fed high-grain rations. However, this can cause subacute ruminal acidosis (SARA), a metabolic disorder in dairy cows that is usually accompanied by dysbiosis of the rumen microbiome. Postbiotics that contain functional metabolites provide a competitive niche for influential members of the rumen microbiome, may stabilize and promote their populations, and, therefore, may attenuate the adverse effects of SARA. Methods: This study used a total of 32 rumen-cannulated lactating dairy cows, which were randomly assigned into four treatments: no SCFP (control), 14 g/d Original XPC (SCFPa), 19 g/d NutriTek (SCFPb-1X), and 38 g/d NutriTek (SCFPb-2X) (Diamond V, Cedar Rapids, IA) from 4 weeks before until 12 weeks after parturition. Grain-based SARA challenges were conducted during week 5 (SARA1) and week 8 (SARA2) after parturition by replacing 20% dry matter of the base total mixed ration (TMR) with pellets containing 50% ground barley and 50% ground wheat. The DNA of rumen solids digesta was extracted and subjected to V3-V4 16S rRNA gene sequencing. The characteristics of rumen solids microbiota were compared between non-SARA (Pre-SARA1, week 4; Post-SARA1, week 7; and Post-SARA2, weeks 10 and 12) and SARA stages (SARA1/1, SARA1/2, SARA2/1, SARA2/2), as well as among treatments. Results: Both SARA challenges reduced the richness and diversity of the microbiota and the relative abundances of the phylum Fibrobacteres. Supplementation with SCFP promoted the growth of several fibrolytic bacteria, including Lachnospiraceae UCG-009, Treponema, unclassified Lachnospiraceae, and unclassified Ruminococcaceae during the SARA challenges. These challenges also reduced the positive interactions and the numbers of hub taxa in the microbiota. The SCFPb treatment increased positive interactions among microbial members of the solids digesta and the number of hub taxa during the SARA and non-SARA stages. The SCFPb-2X treatment prevented changes in the network characteristics, including the number of components, clustering coefficient, modularity, positive edge percentage, and edge density of the microbiota during SARA challenges. These challenges reduced predicted carbohydrate and nitrogen metabolism in microbiota, whereas SCFP supplementation attenuated those reductions. Conclusions: Supplementation with SCFP, especially the SCFPb-2X attenuated the adverse effects of grain-based SARA on the diversity and predicted functionality of rumen solids microbiota. [ABSTRACT FROM AUTHOR]