Journal of Dairy Science最新文献

{"title":"Invited review: Lung ultrasonography-Improving our understanding and management of respiratory disease in young calves.","authors":"Sébastien Buczinski, Terri L Ollivett, Bart Pardon","doi":"10.3168/jds.2025-26764","DOIUrl":"https://doi.org/10.3168/jds.2025-26764","url":null,"abstract":"<p><p>Lung ultrasonography (LUS) has emerged as an on-farm tool that can rapidly characterize pulmonary abnormalities in young cattle. This tool is particularly useful for detecting the lung consolidation associated with bronchopneumonia following bacterial infection of the lower airway. The aim of this review is to discuss on-farm LUS techniques, the contributions of LUS to bovine respiratory disease research, and potential applications in cattle practice. Lung ultrasonography studies consistently demonstrate associations between lung consolidation and negative economic outcomes, including (among others): reduced growth, lower future carcass weights in veal calves, premature culling, and lower future milk production in dairy cattle. Within the context of subclinical pneumonia (presence of lung lesions in the absence of abnormal clinical signs), the dynamics of respiratory tract infections and the presence of specific risk factors could be better characterized. Given its higher diagnostic sensitivity (ranging from 66% to 94%) and specificity (from 66% to 100%) for detecting calves affected with lung disease, LUS is a better reference test for randomized clinical trials evaluating therapy and vaccine efficacy compared with clinical scoring. In the handful of vaccination studies available, LUS results were significantly different between experimental groups despite no effect on clinical scores, demonstrating the added value of using this ancillary test as an outcome. On-farm applications of LUS include pneumonia detection for the purposes of monitoring patterns of disease, evaluating of clinical detection accuracy, initiating treatment, evaluating treatment efficacy, cure definition or determining duration of treatment, conducting pre-purchase examinations, and making culling decisions. Two LUS scoring systems that are based on quantifying lung consolidation, and therefore are best for characterizing bronchopneumonia, are commonly in use. Currently, there is no LUS scoring system for quantifying the severity of diffuse airway injury from viral infections or interstitial disease in dairy or veal calves. There is a need for a core outcome set for studies on respiratory-focused research that include LUS parameters as case definitions or treatment responses, in addition to key performance indicators (production and health outcomes), in order to motivate the dairy, dairy beef, and veal calf industries toward more sustainable production. Fortunately, momentum for implementing on-farm LUS is growing, but more work needs to be done to increase producer awareness and expand veterinary, research, or technical training. Certificate programs to document well-trained and highly qualified-professionals may prove useful for promoting on-farm implementation.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of 3-nitrooxypropanol on enteric methane emissions and milk production characteristics in dairy cows fed a high corn-silage diet in different environmental conditions.","authors":"M Moschini, F Froldi, F Piccioli-Cappelli, P Bani, E Fiorbelli, A Gallo, I Mueller, L F M Tamassia, R Zihlmann, P Bulgarelli, S Agazzi, E Trevisi, L Cattaneo","doi":"10.3168/jds.2025-26640","DOIUrl":"https://doi.org/10.3168/jds.2025-26640","url":null,"abstract":"<p><p>This study examined the effect of 3-nitrooxypropanol (3-NOP) on enteric GHG emissions, milk production, and the blood metabolic profile of lactating Holstein dairy cows across 2 experiments, one conducted during the summer and the other in fall. Thirty mid lactation multiparous cows, with an average (mean ± SD) of 190 ± 72 DIM and a milk yield of 36.8 ± 7.5 kg/d, were included in the summer experiment. In the fall experiment, cows averaged 158 ± 74 DIM and a milk yield of 36.8 ± 4.6 kg/d. Experiments were structured as longitudinal studies with repeated measurements in a completely randomized design, with an initial 14-d covariate period, a 63-d treatment period, and a 14-d washout period. Cows were randomly assigned to 1 of 2 treatment groups: (i) the control group (CTR), receiving a corn silage-based diet supplemented with a placebo, and (ii) the 3-NOP group, receiving the same diet supplemented with 60 mg/kg DM of 3-NOP. Cows were housed in a freestall barn, with individual monitoring of feed intake, and fed a TMR ad libitum delivered 1 time a day. The enteric CH₄, CO₂, and H₂ emissions were measured using a GreenFeed unit. The 3-NOP reduced enteric CH₄ production (46%), yield (46%), and intensity (44%), regardless of the season, but increased H₂ and CO₂ emissions. In the summer, 3-NOP cows reduced DMI (5.7%) and meal size and increased the feed (4.8%) and dairy (4%) efficiencies but not in the fall. Adding 3-NOP increased the apparent OM, CP, and NDF digestibility, independently of the season. There was no effect of 3-NOP on milk yield, although supplementing 3-NOP increased the milk protein and casein and decreased milk urea contents. Saturated fatty acids (FA) increased with 3-NOP, regardless of the phase of the study. In the summer season, 3-NOP supplementation increased de novo FA (7.3%) and decreased mixed FA (6.7%), whereas in the fall, SFA decreased (2.3%) and MUFA increased (6.8%) compared with CTR. Supplementing 3-NOP affected the molar proportions of rumen VFA. Acetate was reduced, whereas butyrate, valerate, isovalerate, and caproate were increased by 3-NOP. Plasma concentrations of urea, nonesterified FA, Zn, and advanced oxidation protein products decreased with 3-NOP, but blood cholesterol and myeloperoxidase increased. In conclusion, including 3-NOP in a high corn-silage and high-starch diet almost halved enteric CH₄ emissions without adversely affecting milk yield and composition.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A history of lameness is associated with reduced proportions of collagen type I relative to type III in the digital cushions of dairy cattle.","authors":"J P Wilson, M J Green, L V Randall, J N Huxley, A Alibhai, H J Ferguson, C S Rutland","doi":"10.3168/jds.2025-27109","DOIUrl":"https://doi.org/10.3168/jds.2025-27109","url":null,"abstract":"<p><p>Hoof horn lesions (HHL) are a highly prevalent and recurrent causes of lameness in dairy cattle globally. The digital cushion is composed of 3 cylinders of adipose tissue embedded in a system of collagenous connective tissue, which are designed to reduce the risk of HHL onset. Previous research has identified that animals with a history of lameness and HHL are more likely to have a reduced digital cushion volume in their lateral digits, but the impact on the histological structure remains unknown. Collagen is an important fibril related to adipose tissue structure and function, but its role in the digital cushion is poorly understood. Our study aimed to examine the proportions of type I and type III collagen within the digital cushions of dairy cattle at cull, and to investigate associations with digital cushion volume, lameness, and HHL occurrence throughout the animal's life. This retrospective cohort study resulted in 599 digital cushions being dissected from the hind feet of 54 animals. Digital cushion tissue underwent picrosirius red staining, combined with systematic random sampling and collagen content analysis. The results described the relative proportions of type I and type III collagen. The proportion of type I collagen was used as the outcome variable in multivariable linear regression models. The median (minimum-maximum) proportion of collagen that was type I contained within the lateral and medial digits was 56.2% (23.6%-83.8%) and 59.6% (13.3%-92.7%) respectively. The proportion of type I collagen was lower in animals that had a history of HHL and lameness throughout their lives. Animals with a lower BCS at cull or that were culled at a later parity had less type I collagen in their lateral digits at cull. Animals with a higher digital cushion volume also had an increased proportion of type I collagen in their lateral digits at cull. Our results have highlighted the histological impact that HHL have on the structure of the digital cushion. We hypothesized that localized inflammation associated with HHL was associated with a remodeling of the adipose tissue within the digital cushion, which would predispose the individual to a future of lameness and HHL.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating the effect of hoof health on milk yield in British dairy cattle.","authors":"João S Afonso, Sara Mitchell, Roel Driesen, Jon Reader, Vivi M Thorup, Almudena M Argüello, Georgios Oikonomou, Jonathan Rushton","doi":"10.3168/jds.2025-26658","DOIUrl":"https://doi.org/10.3168/jds.2025-26658","url":null,"abstract":"<p><p>Lameness is a highly prevalent and economically important health problem in British dairy cattle. Previous studies have highlighted a delay between lameness onset and farmer detection. This lag, combined with the low sensitivity of clinical diagnosis, limits early intervention, thereby worsening both production and animal welfare outcomes. Notably, the negative effects of lameness can persist even after clinical recovery. Understanding the burden of health issues is essential for informed decision making at the farm level and beyond. This study quantifies the impact of hoof-health disorders on milk yield in British dairy cattle. Data were obtained from 6,050 cows across a nonrandom sample of 11 farms, including repeated daily milk yield records, totaling ∼2.1 million cow-days. A mixed linear model was developed to account for the time-dependent, correlated nature of milk yield data, using a first-order autoregressive correlation structure. An event study design allowed investigation of milk yield trajectories before and after clinical diagnosis. Farmer-reported data were used to identify hoof-related lameness events. After adjusting for mastitis, stage of lactation, parity, farm, season, and breed, cows with a hoof-health event produced on average 1.47 kg/d less milk than healthy cows. For severe cases, the average daily reduction reached 2.05 kg. The event study revealed that milk yield declines were detectable before clinical diagnosis and persisted after treatment. These findings underscore the impact of hoof-health disorders on dairy productivity and highlight the need for earlier detection as it could help farmers mitigate milk losses, reduce treatment costs, and enhance animal welfare.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Longitudinal characterization of the adipose tissue metabolome in dairy cows during the transition from cessation to resumption of lactation.","authors":"H Sadri, M H Ghaffari, H Sauerwein, S Schuchardt, J Martín-Tereso, John Doelman, J B Daniel","doi":"10.3168/jds.2025-27136","DOIUrl":"https://doi.org/10.3168/jds.2025-27136","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Dairy cows undergo profound metabolic challenges as they transition from lactation cessation to lactation resumption. Adipose tissue (AT), serving as the primary energy reserve and an active endocrine organ, plays a crucial role in these adaptations. Thus, the objective of the current study was a comprehensive characterization of the metabolic changes in the AT metabolome of Holstein dairy cows as they transitioned from one lactation cycle to the next, providing key insights into the dynamic adaptations crucial for maintaining energy homeostasis and optimizing lactational performance. Twelve Holstein dairy cows (BW = 745 ± 71 kg, BCS = 3.43 ± 0.66), housed in tiestalls, were dried off 6 wk before their expected calving date (mean dry-off time = 42 d). Cows were individually fed ad libitum TMR, consisting of grass silage, corn silage, and concentrate during lactation and a mixture of corn silage, barley straw, and concentrate during the dry period. The metabolome was characterized in subcutaneous AT samples collected on wk -7 (before drying off), -5 (after drying off), and wk -1 and 1 relative to calving. A targeted metabolomics approach was employed using the MxP Quant 500 kit (Biocrates Life Sciences AG), integrating liquid chromatography, flow injection, and electrospray ionization triple quadrupole MS. Statistical analysis of the AT metabolite data was conducted using MetaboAnalyst 5.0, enabling various multivariate analyses, including principal component analysis, partial least squares discriminant analysis, hierarchical clustering, and the generation of informative heatmaps. Multivariate analyses revealed distinct and dynamic alterations in the AT metabolome, with minimal changes during the early dry period (wk -7 to -5) followed by pronounced metabolic reprogramming close to calving (wk -1 to 1). Amino acid profiles in AT remained stable during late gestation but declined significantly in Ala, Asp, and Gln between wk -1 and wk 1, likely due to increased utilization within AT, redirecting carbon skeletons from these AA toward glyceroneogenesis and the re-esterification of fatty acids (FA) into triglycerides. Such a shift in AA metabolism may also facilitate interorgan nutrient exchange, with Ala export through the glucose-Ala cycle providing essential gluconeogenic substrates to the liver during early lactation. Moreover, acylcarnitine profiles remained unchanged, reflecting the role of AT as a long-term lipid reservoir rather than a metabolically active site for FA oxidation. The data revealed a biphasic pattern in diglycerides and extensive remodeling of phosphatidylcholines, underscoring dynamic cellular membrane adaptations to heightened lipolytic activity and increased energy demands during the immediate postpartum period. Notably, sphingomyelin remained stable throughout the transition, suggesting potential mechanisms in preserving membrane integrity and ensuring cellular stability under fluctuating metabolic stress. Together, th","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A synthetic analog of the bovine-appeasing pheromone facilitates adaptive responses during disease in dairy calves.","authors":"J Garcia-Alvarez, E Descout, A Cozzi, S M Rutter, A Beaver","doi":"10.3168/jds.2025-26759","DOIUrl":"https://doi.org/10.3168/jds.2025-26759","url":null,"abstract":"<p><p>Gastrointestinal and respiratory infections are the main cause of morbidity and mortality in the first months of life in young dairy calves, with an important negative effect on animal welfare and production. Appeasing pheromones act through olfactory pathways to influence stress-related physiological and behavioral responses in mammals and have shown promising results in a variety of domestic animals. A synthetic analog of the bovine-appeasing pheromone (BAP) has been observed to reduce veterinary costs in dairy calves and modulate the clinical expression of respiratory illness, potentially influencing the timing of symptom presentation and immune response in beef calves and young bulls. The objectives of this study were to observe the influence of BAP on disease incidence and recovery in dairy calves, and on physiological and behavioral stress responses during naturally occurring disease episodes. In the present randomized controlled trial, 72 female Holstein Friesian dairy calves were randomly allocated to receive BAP or a placebo once every 2 wk from birth to 4 wk after milk weaning. Clinical disease affected 33 calves, across a total of 44 recorded illness episodes (24 in the BAP group and 20 in the placebo group; no significant difference between groups). Conditions included gastrointestinal infections, respiratory infections, navel infections, and other clinical symptoms such as fever and lameness. It was hypothesized that diseased dairy calves in the BAP treatment would display fewer signs of stress compared with calves receiving the placebo and their recovery would be faster. Calves were equipped with triaxial accelerometers on the hind leg postnatally, and their activity levels were observed throughout the trial. Data on live weight gain was also obtained, and calves were fitted with heart rate monitors every week for at least 24 h to assess heart rate variability (HRV). During periods of disease, BAP was associated with a reduction in the activation of the neuroendocrine system as evidenced by higher HRV parameters, including increased standard deviation of beat to beat of normal sinus beats (SDNN) and root mean squares of successive differences (RMSSD). Calves in the BAP group also displayed a faster recovery of their activity levels and HRV parameters compared with the placebo group. These results suggest a potential welfare benefit of the use of BAP during bouts of sickness.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of seasonal microbiome changes in raw milk between conventional and organic farming practices.","authors":"Daria Van De Grift, Eiseul Kim, Seung-Min Yang, Alyssa Thibodeau, Jenifer Cruickshank, Lisbeth Goddik, Si Hong Park","doi":"10.3168/jds.2025-26743","DOIUrl":"https://doi.org/10.3168/jds.2025-26743","url":null,"abstract":"<p><p>Raw milk microbiota is influenced by farming practices, environmental exposure, and seasonal changes. This study investigated how organic and conventional dairy farming practices influence the microbial composition of raw milk over a 1-yr period. Milk and environmental samples were collected quarterly from 7 dairy farms (4 organic and 3 conventional) in Oregon and analyzed using microbiome sequencing. Across all seasons, the microbial community of raw milk was largely similar between organic and conventional farms, with Escherichia-Shigella being the most abundant genus. Aerobic plate counts were significantly higher in conventional raw milk during winter and summer. Organic milk showed greater seasonal variation in α diversity (Shannon index 1.81 ± 0.40 in winter to 1.01 ± 0.34 in fall), whereas conventional milk remained more stable. No significant β diversity differences were observed between farming types. Shared microbial taxa between raw milk and environmental sources varied by season and farming type, reflecting the influence of confinement and grazing. For example, Romboutsia was more abundant during grazing seasons in organic farms, whereas Clostridium sensu stricto 1 appeared uniquely in conventional milk in winter. These seasonal and housing-related trends highlight how farm management shapes milk microbiota.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INVITED REVIEW: Animal welfare in pasture-based dairy systems-A systematic scoping review to identify progress, priorities, and future directions.","authors":"M Verdon, L Field, K Schütz, R Bryant","doi":"10.3168/jds.2025-26981","DOIUrl":"https://doi.org/10.3168/jds.2025-26981","url":null,"abstract":"<p><p>This systematic review examines the past and present focus of welfare research in pastoral dairy production systems and uses these insights to suggest future research priorities. We included original research articles published between 2000 and 2024 that studied dairy cows, weaned youngstock or preweaning calves in pastoral dairy systems and reporting on animal welfare outcomes. Review articles were excluded. Three thousand peer-reviewed manuscripts written in English were screened for inclusion. The 678 eligible articles extracted were categorized by welfare domain using the Five Domains framework (i.e., nutrition, health, environment, behavior, and mental state) and inductively assigned up to 5 descriptive key words to reflect the main welfare issue(s) addressed. Welfare research output increased from 19 to 60 publications per year over the past (2000-2019) to present periods (2020-2024), respectively. Most studies (74.0%) focused on cows, with fewer publications on the calf and weaned youngstock. Across all cattle classes and years, health was the most represented welfare domain, addressed by 69% of calf, 54% of youngstock, and 53% of cow studies, whereas the mental state domain was addressed in less than 1% of research. The article key words were used to assess changes in welfare focus topics over time. From 2000 to 2019, 34 calf welfare topics were identified, with research primarily focusing on colostrum management and passive immunity (21%). Presently (2020-2024), of the 42 topics published on the calf, extended suckling systems (19%) dominate (i.e., systems providing extended cow-calf contact). For weaned youngstock, 33 topics were published between 2000 and 2019, and parasitism was a key welfare theme. The present youngstock research continues to focus on parasite control (19% of studies covering 31 topics). Past research on cow welfare (94 topics) concentrated on pasture access and lameness. In recent years, 106 different topics have been covered by the cow literature. Of these, emerging technologies, such as virtual fencing and automated health monitoring, represent the most studied topics (14%), closely followed by pasture access (13%). Future research should increase focus on calves and youngstock, particularly in relation to environment, nutrition, behavior, and their effects on mental state. Extended suckling systems warrant continued attention. Longitudinal studies exploring how early-life environments shape heifer resilience and adaptability are encouraged. Addressing climate-related challenges while preserving the welfare benefits of pasture access is critical. Progress will require ongoing collaboration between science and industry, balancing immediate needs with investment in longer-term, transformative welfare solutions.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic insights into bovine spastic syndrome (Crampy) in Holstein dairy cattle.","authors":"Gabriella Condello, Flavio S Schenkel, Isis C Hermisdorff, Colin Lynch, Christina M Rochus, Brian J Van Doormaal, Filippo Miglior, Christine F Baes","doi":"10.3168/jds.2025-27026","DOIUrl":"https://doi.org/10.3168/jds.2025-27026","url":null,"abstract":"<p><p>Bovine spastic syndrome, known as Crampy, is a neuromuscular disorder in cattle. Affected cattle, 2 yr or older, suffer from involuntary muscle spasms in their hind limbs, leading to discomfort and reduced mobility. This often results in early culling from the herd, causing substantial financial loss for producers. Given the welfare implications and economic burden associated with Crampy, it is crucial to identify effective strategies to mitigate its occurrence. In this study, we assessed the feasibility of genetic selection to reduce Crampy by estimating variance components, evaluating the effect of incorporating genomic information, investigating Crampy's relationship with other economically important traits, and identifying genomic regions associated with Crampy in Canadian Holstein dairy cattle. A dataset comprising 54,826 animals, including 1,952 cases of Crampy, from 678 Canadian dairy herds, was provided by Lactanet Canada (Guelph, ON, Canada). Of these animals, 22,408 (including 408 with Crampy) were genotyped. Both threshold and linear models were used to estimate variance components, with observed scale h² estimates ranging from 0.057 to 0.085. The inclusion of genomic data significantly increased the reliability of breeding values by 5% to 17%. Through a GWAS using GCTA software, a total of 41 significant SNPs were found to be significantly associated with Crampy. Functional analysis revealed 44 genes, among which we have highlighted the genes WNK2 (BTA8), DTNBP1 (BTA23), and ADK (BTA28), which have been associated with ion transport, muscle function, and neuron signaling, respectively. Enriched colocated QTL annotations linked to ketosis, muscle calcium content, and muscle zinc content were also identified, highlighting the role of metabolic processes and mineral homeostasis in muscle function. Breeding value correlations between Crampy and production, health, longevity, and type traits, and the selection indices were moderately low but favorable, indicating that current breeding strategies may indirectly select against Crampy. These findings highlight genomic selection as a viable strategy to mitigate Crampy in Canadian dairy herds, emphasizing the need for continued phenotyping for this disorder and optimization of breeding practices to improve animal welfare and sustainability.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exterior traits of milk-deprived and milk-fed calves as indicators for body condition or nutritional status.","authors":"Jan Kurek, Theresa M Liegsalz, Anton M Vorndran, Anna Kurek, Veronika Huber, Georg Hammerl, Hubert Spiekers, Julia Steinhoff-Wagner","doi":"10.3168/jds.2025-27130","DOIUrl":"https://doi.org/10.3168/jds.2025-27130","url":null,"abstract":"<p><p>The intake of sufficient milk in the postnatal age is crucial for the physical development of the calf. Farmers struggle to assess whether the calves have consumed sufficient colostrum or milk on farms with unobserved birth, in cow-bonded calf-rearing systems or early group housing with unobserved bucket feeding. The study aimed to find exterior traits that can be used to classify the body condition and nutritional status of suckling calves during wk 1 to 4 after birth. In a second dataset, threshold values for the percentage change in flank circumference in relation to the milk intake (% BW) were determined in calves aged 8 to 10 d after birth. Therefore, at first, calves (n = 85) were measured and scored on 2 farms before feeding and 1 h after voluntary milk intake in the morning. For the second dataset, 10 calves had a voluntary uptake of different milk volumes (range % BW) from d 8 to 10. Significant differences in body parameters between the age groups and sex were analyzed using a Kruskall-Wallis nonparametric ANOVA. A nonparametric receiver operating characteristic analysis (ROC) was used to derive the threshold values for the distinction between milk-deprived and milk-fed status in calves and threshold values for changes in flank circumference in relation to milk intake % BW. The intake-associated gain of the calves could be visualized by measuring and scoring the external body parameters. Sex influenced only flank circumference (milk-fed) in wk 2. Using the ROC, the flank width showed a better model quality (0.54-0.68 vs. 0.39-0.64) and true-positive rate (64%-79% vs. 47%-87%) than the flank circumference. The left or right hunger pit showed the best model quality (0.61-1.00) and excellent true-positive rates (76%-100%). The false-positive rate was in the lower range (8%-23%). Following milk intake, changes in flank circumference were more distinctly detectable at lower intake levels (below 5% of BW) than at higher levels. Within this lower range, the ROC analysis yielded excellent area under the curve values and high accuracy in distinguishing between the amount of milk consumed % BW. In contrast, as milk intake increased to 6% to 10% of BW, the diagnostic performance declined noticeably. Suitable indicators were identified to sufficiently assess the body condition and nutritional status of newborn suckling calves, which could be implemented on farms to recognize and prevent critical situations in the absence of milk intake.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145273243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}