Journal of Dairy Science最新文献

{"title":"Case studies investigating the epidemiology of hyperketonemia in grazing dairy cows in early lactation: Incidence, prevalence, and time to resolution of hyperketonemia.","authors":"S J Hendriks, J R Roche, J A A McArt, T M Grala, S-A Turner, C R Burke, B Kuhn-Sherlock, C V C Phyn","doi":"10.3168/jds.2024-25205","DOIUrl":"https://doi.org/10.3168/jds.2024-25205","url":null,"abstract":"<p><p>Most cows experience a degree of negative energy balance due to an energy deficit during early lactation leading to the mobilization of body tissue to support milk production which results in the production of ketone bodies. Elevated ketones have been associated with an increased risk of clinical ketosis and reduced cow performance and health. The objectives of this study were to: 1) characterize the incidence and prevalence of hyperketonemia (HYK) and severe HYK (Sev-HYK) in 3 seasonal calving herds of grazing dairy cows in early lactation, and 2) characterize the time to resolution of HYK based on the timing and degree of HYK. Grazing cows from 3 dairy farms were tested 15 times (mean ± SD; 14.9 ± 0.4 tests) for HYK between 1 and 35 DIM using a hand-held meter. Hyperketonemia was defined as blood BHB ≥ 1.2 to 2.9 mmol/L and Sev-HYK was defined as blood BHB ≥ 3.0 mmol/L. Associations between time to resolution of HYK and factors influencing this (farm, timing and magnitude of the first positive HYK test), were investigated by survival analysis using Cox regression. A total of 749 (76%) of 980 eligible cows were classified with HYK or Sev-HYK at least once within 35 DIM. Cumulative incidence was 71% within 14 DIM and varied across Farm A (40%), Farm B (76%), and Farm C (74%). Cumulative incidence of Sev-HYK was 11% within 35 DIM and varied across Farm A (12%), Farm B (18%), and Farm C (6%). Peak incidence of HYK occurred at 3 DIM, when 34% of cows had their first positive HYK test; however, peak HYK incidence and timing of peak incidence varied widely between the 3 herds (20% at 7 DIM on Farm A, 38% at 4 DIM on Farm B, and 58% at 3 DIM on Farm C). Median time from first positive HYK test (1.2 to 2.9 mmol/L) to a negative test (<1.2 mmol/L) was 3.3 d. In multivariable models, blood BHB concentration (≥1.2 to < 2.0 mmol/L vs. 2.0 to 2.9 mmol/L) and timing (≤4 DIM vs. > 4 DIM) of the first positive HYK test were associated with time taken to resolve HYK (blood BHB < 1.2 mmol/L) within 35 DIM. Cows with blood BHB 1.2 to < 2.0 mmol/L at their first positive HYK test were 43% more likely to resolve HYK than cows that tested 2.0 to 2.9 mmol/L at their first positive test within 35 DIM. Further, cows that first tested positive after 4 DIM were 62% more likely to resolve HYK than cows that first tested positive within the first 4 DIM. Our results indicate substantial variation in the incidence and prevalence of HYK across 3 case study herds in seasonal calving, pasture-based systems. The time of HYK onset relative to calving and BHB concentration at the first HYK-positive test can influence the time taken to resolve HYK.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727147","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":"Feeding behavior of Holstein and Jersey cows fed diets based on either alfalfa silage or corn silage at 2 forage fiber levels.","authors":"O I Santana, M E Uddin, M A Wattiaux","doi":"10.3168/jds.2024-25708","DOIUrl":"https://doi.org/10.3168/jds.2024-25708","url":null,"abstract":"<p><p>Our objective was to assess the effects of 2 levels of forage neutral detergent fiber (FNDF) mainly from either alfalfa silage (AS) or corn silage (CS) on feeding behavior of Holstein and Jersey cows. Twenty-four lactating primiparous cows (12 Holsteins and 12 Jerseys) were used in a triplicated split-plot 4 × 4 Latin Square study in which breed formed the main plots and diets were arranged in a 2 × 2 factorial in the sub-plots. Dietary treatments were 2 FNDF levels [19% FNDF (LF) or 24% FNDF (HF)] and 2 FNDF sources (70:30 or 30:70 ratio of AS:CS). During each 28-d period, samples of TMR and individual cow refusals were collected to determine particle size distribution using particle separator with 3 sieves and a bottom pan. Eating time (ET, min/d) was recorded through visual observation and time spent ruminating (RT, min/d) was measured using a neck-collars recording system. Saliva samples were collected to determine concentration of urea-N and explore possible effects on N recycling. Compared with Holsteins, Jerseys had lower FNDF intake (kg/d; -25%) but greater FNDF intake as a percentage of BW (+12%). The particle size distribution of the DM consumed reflected closely the particle size distribution of the diet and did not differ between breeds. However, cows of both breeds sorted for long particles and sorted against short particles and compared with Holstein, jersey cows exhibited more pronounced feed-sorting behaviors. Overall ET, RT, and chewing time (ET + RT) averaged (mean ± SD) 247 ± 60, 495 ± 110, and 739 ± 133 min/d. Eating time did not differ between breeds, but Jerseys had greater RT than Holsteins (519 ± 99 vs. 465 ± 113 min/d) and greater ET and RT expressed per kg of BW, DMI, FNDF intake. Source, level, and interaction between source and level of FNDF influenced the percentage of DM consumed as long, medium, and short particles, but only FNDF level influenced the percentage of DM consumed as fine particles. Cows fed the HF diet based on AS had lower DMI (kg/d; -12%) but greater rumination time per kg of DMI (+22.9%) compared with cows fed other diets. The interaction between level and source of FNDF in the diet influenced ET and RT but not chewing time. In addition, ET was greater (+6.7%) when cows were fed AS-based diets than CS-based diets (255 ± 62 vs. 239 ± 58 min/d) and RT was greater (+8.1%) for HF-fed than LF-fed cows (512 ± 117 vs. 473 ± 98 min/d). Neither breed nor dietary treatments influenced saliva urea-N (11.6 ± 2.01 mg/dL). In brief, we found interactions between source and level of FNDF in the diet, most notably a reduction in DMI and cow performance when the FNDF level was increased with AS, but not with CS. Except for the sorting of fine particles, under the conditions of this study, both breeds responded in the same way to changes in the dietary particle size distribution associated with an increased level of FNDF regardless of forage source.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727233","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":"Impact of proportion of pasture in the cow diet and seasonality on the milk metabolome as determined by ¹H-NMR.","authors":"Paula Rojas-Gómez, Raghunath Pariyani, Lorraine Bateman, Denis Lynch, Mark Timlin, Michael Dineen, Noel A McCarthy, André Brodkorb, Anita R Maguire, Michael O'Donovan, Deirdre Hennessy, Thomas Brendan Murphy, James A O'Mahony, Tom F O'Callaghan","doi":"10.3168/jds.2024-26168","DOIUrl":"https://doi.org/10.3168/jds.2024-26168","url":null,"abstract":"<p><p>This study investigates the impact of varying proportions of pasture (high, medium, no-pasture) in the diet of cows and seasonality on the milk metabolome throughout lactation using proton nuclear magnetic resonance (¹H-NMR) spectroscopy. This study explored the potential to differentiate milks from varying levels of pasture in the cows diet and highlight potential biomarkers for authentication A total of 54 spring calving cows were assigned to the 3 diet treatments for the duration of lactation. Weekly bulk milk samples were collected from each herd. Over 37 weeks (March-November), 43 metabolites representing diverse chemical classes, including amino acids and nitrogenous compounds, carbohydrates, volatile fatty acids, organic acids, and alcohols were quantified. Significant dietary and seasonal influences on the milk metabolome were characterized, with signature differences attributed to the proportion of pasture in the cow's diet and the season of milk production. Receiver operating characteristic (ROC) analysis of the milks from different feeding systems across lactation highlighted the potential of the milk metabolome to distinguish pasture from non-pasture derived milks, with a series of metabolites demonstrated as excellent biomarkers, including hippurate. Multivariate analysis also highlighted dimethyl sulfone as key metabolite for the distinction between different diet regimens. These findings highlight the diversity and complexity of the composition of milk as affected by seasonality, and signature characteristics that are associated with pasture-based feedings systems. As \"Grass-Fed\" dairy products become more prominent on the market, the analysis of the milk metabolome using ¹H-NMR shows significant promise for utilization as a tool for authentication purposes.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727242","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":"Potential of anogenital distance as a genetic selection trait in Canadian Holsteins.","authors":"G R Dodd, F S Schenkel, F Miglior, T C Bruinjé, M Gobikrushanth, J E Carrelli, M Oba, D J Ambrose, C F Baes","doi":"10.3168/jds.2024-26021","DOIUrl":"https://doi.org/10.3168/jds.2024-26021","url":null,"abstract":"<p><p>Maintaining optimal fertility in dairy cattle herds is a global challenge that is typically addressed through the genetic selection of fertility indicator traits. However, many of the traits currently implemented in breeding programs are heavily influenced by environmental factors, resulting in a slow rate of genetic improvement. Anogenital distance (AGD) has recently emerged as a promising fertility indicator trait due to its association with favorable reproductive outcomes and its higher heritability estimates compared with currently evaluated traits. This study aimed to enhance the understanding of AGD's genetic potential by estimating its genetic parameters in Canadian Holsteins, assessing the reliability of breeding values, comparing pedigree BLUP to single-step genomic BLUP approaches, and estimating the correlation between AGD breeding values and those of currently evaluated traits. The dataset used in this study comprised 5,541 Canadian Holstein cows and heifers from 20 herds, collected between 2015 and 2020. The final dataset consisted of 4,988 animals with AGD phenotypes after filtering. The pedigree-based heritability estimate for AGD was 0.39 ± 0.04, whereas the incorporation of genomics resulted in a lower estimate of 0.37 ± 0.03. The reliability of estimated breeding values ranged from 0.49 ± 0.03 for phenotyped animals to 0.81 ± 0.05 for proven sires with at least 30 phenotyped daughters. The integration of genomic information improved the reliability of breeding values, with gains ranging from 0.01 gain for proven sires to 0.14 relative gain for unproven sires. High gain in observed reliability for females without records was demonstrated when genomic information was included, using both split forward validation (0.26) and 5-fold cross-validation (0.14). The AGD breeding values showed moderate unfavorable correlations with relative breeding values of age at first service and production traits including milk yield, fat yield, and protein yield. This suggests that AGD may influence reproductive maturity in heifers but could also have an unfavorable association with production traits, highlighting the need for balanced breeding strategies that consider both fertility and production outcomes. Future studies should aim to expand phenotype data across lifetimes and breeds and estimate genetic correlations with traditional reproduction and production traits using multitrait models.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727067","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 randomized controlled trial to evaluate the effect of 2 hoof trimming methods at dry-off on hoof lesion and lameness occurrence in dairy cattle.","authors":"G Stoddard, N Cook, S Wagner, L Solano, E Shepley, G Cramer","doi":"10.3168/jds.2024-26068","DOIUrl":"https://doi.org/10.3168/jds.2024-26068","url":null,"abstract":"<p><p>Despite hoof trimming (HT) being a recommended procedure for hoof lesion and lameness prevention, there is limited data on the efficacy of different HT methods. Our objective was to compare the effects of HT cows at dry-off with the functional method that uses a little model (LIT) to an adaptation with bigger modeling (BIGM) of the higher load-bearing hoof on the occurrence of new hoof lesions and the risk for lameness in the next lactation. Cows scheduled for their regular HT at dry off were enrolled weekly from 3 sand bedded free-stall housed herds located in Wisconsin (n = 2) and Minnesota (n = 1). Cows were eligible for enrollment if they did not have hoof horn lesions at their dry-off HT. Cows were allocated to either LIT or BIGM weekly. Locomotion scores were collected on a biweekly basis from 2 herds once before enrollment and until their subsequent HT or up to 165 DIM. Two trained hoof trimmers collected hoof lesion data either during the cow's scheduled mid-lactation HT between 100 and 165 DIM or during an HT prompted by identification as a lame cow by farm personnel. Data were analyzed using multivariable logistic regression with the presence of any hoof lesion as the outcome of interest and multivariable Cox proportional hazards models with the presence of lameness as the outcome of interest. A total of 1,556 cows were enrolled, with 790 (51%) cows in the LIT treatment and 766 (49%) cows in the BIGM treatment. The average DIM at the cow's next HT was 113 (95% CI: 111-114). A total of 205 (16.2%) of the 1265 cows were identified with a lesion before 165 DIM. A total of 501 (43%) of the 1167 cows were identified as lame following enrollment. There was no evidence of a difference between the LIT and BIGM groups overall when presence of any hoof lesion was considered as the outcome. The median time to lameness was 193 d for LIT and 203 d for BIGM. For the hazard of lameness outcome there was no evidence of a difference between the LIT and BIGM groups overall. However, for both the presence of any hoof lesion and lameness outcomes, a cow's lactation group modified the effect of BIGM. First lactation cows trimmed with BIGM had reduced risk of any hoof lesion and specifically reduced risk for hoof horn lesions (risk difference 6.1% (95% CI: 9.6 - 2.5) and odds 76% (OR 0.24, 95% CI: 0.10 - 0.58). In addition, first lactation cows and cows with an enrollment locomotion score < 3 had a lower hazard of becoming lame in the following lactation if they were allocated to the BIGM treatment, compared with cows trimmed with LIT. In summary, the effect of the BIGM trimming method was modified by factors related to parity and prior lameness status, possibly influenced by bone exostosis on P3. Therefore, the BIGM HT method should be considered to prevent lameness and hoof lesions when animals are trimmed at their 1st lactation dry-off trim.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727121","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":"Absorption, metabolism, and bioconversion of trans-palmitoleic acid in C57BL/6J mice: Implications for lipid metabolism.","authors":"Meng Wei, Zeqiang Zhou, Kequn Lin, Zeyuan Deng, Jing Li","doi":"10.3168/jds.2024-25913","DOIUrl":"https://doi.org/10.3168/jds.2024-25913","url":null,"abstract":"<p><p>Trans-palmitoleic acid (TPA), a naturally occurring trans fatty acid found in ruminant-derived products such as dairy, has been associated with various potential health benefits. However, its digestion, absorption, tissue distribution, and metabolic properties following oral administration remain insufficiently understood. Here, we conducted pharmacokinetic analyses in C57BL/6J mice to evaluate the absorption, tissue distribution, and metabolism of TPA following oral administration. Our data showed that the plasma concentration of TPA peaked at 9.1 µg • mL^-1 at 15 min post-administration, with a terminal elimination half-life of 201.1 min. Moreover, TPA was efficiently distributed to the heart, lung, liver, kidney, brain and adipose tissue, reaching peak concentrations within 30 to 60 min. These results indicate that TPA is rapidly digested, absorbed, and distributed across multiple tissues in mice, while exhibiting slow metabolic clearance and an extended residence time in vivo. Within 0 to 480 min following oral administration, TPA underwent bioconversion to trans-vaccenic acid (TVA) and cis-9, trans-11 conjugated linoleic acid (9c11t-CLA), both of which are recognized for their extensive health benefits. The bioconversion rates were 71.57-72.44% for TVA and 44.05-53.23% for 9c11t-CLA. Furthermore, TPA significantly reduced triglyceride and total cholesterol levels in steatosis hepatocytes. Notably, inhibiting the bioconversion of TPA to TVA and 9c11t-CLA did not impair its ability to reduce lipid accumulation in hepatocytes, suggesting that the beneficial effects of TPA on lipid metabolism are independent of its bioconversion to TVA and 9c11t-CLA. This study provides a reference for dairy fat intake and establishes a foundation for further exploration of the physiological effects of TPA.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727130","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 animal rennet, fermentation-produced chymosin, and microbial coagulants on bovine milk coagulation properties.","authors":"Giorgia Stocco, Dario Casali, Andrea Summer, Elena Mariani, Edward Concar, Suzanne Lantz, Jonathan Goodwins, Claudio Cipolat-Gotet","doi":"10.3168/jds.2024-26167","DOIUrl":"https://doi.org/10.3168/jds.2024-26167","url":null,"abstract":"<p><p>Coagulants play a crucial role in cheese production by catalyzing milk curdling, with traditional animal rennet long serving as the primary choice. However, due to cost, availability, and ethical concerns, various substitutes such as microbial coagulants and fermentation-produced chymosin (FPC) have emerged. This study aimed to evaluate the effects of 8 commercial coagulants, including 1 bovine rennet, 2 bovine FPC, 1 camel FPC, 3 microbial (i.e., Rhizomucor miehei) coagulants, and 1 bovine FPC variant, on the coagulation properties of bovine milk. The coagulants were tested at 3 different doses (35, 50, and 65 International Milk Clotting Units per liter) across 8 batches of unhomogenized, pasteurized, full-fat, bovine milk purchased from different commercial brands, in 2 replicates, for a total of 384 coagulation analyses (8 milk batches × 8 coagulants × 3 doses × 2 replicates). Specifically, traditional milk coagulation properties and curd firmness at given times were assessed using a lactodynamograph. Key findings indicated significant variations in coagulation patterns across the coagulants. Bovine rennet demonstrated an intermediate coagulation profile among all FPC and microbial coagulants. The bovine and camel FPC exhibited faster coagulation than the bovine animal rennet, with the camel FPC showing the quickest coagulation and curd-firming rates. The microbial coagulants, although exhibiting slower coagulation rates for a given dose, produced curd-firming dynamics different from those of all FPC. The bovine FPC variant exhibited high performance comparable to that of the camel FPC in the coagulation process. Overall, this study highlights the distinct coagulation characteristics of various coagulants, offering insights into their suitability for different cheese-making applications. The coagulant dose significantly affected the coagulation pattern, with a clear linear increase in dose influencing gelation and varying effects on other coagulation traits. These findings can guide producers in selecting the optimal coagulant and dose based on specific cheese production needs.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727186","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 variation in novel calf traits using a farmer-centred, co-design approach to data collection.","authors":"M M Axford, M Khansefid, A J Chamberlain, M Haile-Mariam, M E Goddard, J E Pryce","doi":"10.3168/jds.2024-26011","DOIUrl":"https://doi.org/10.3168/jds.2024-26011","url":null,"abstract":"<p><p>Improving calf health on dairy farms contributes to animal welfare and business productivity gains. In recent years, traditional genetic evaluations have broadened to include cow health traits that have economic importance. Calf health is a new frontier to explore but new traits require sufficient data to be effectively evaluated. Researchers who work in countries without obligatory record keeping systems, commonly promote the need to significantly improve record keeping practices to enable research, benchmarking, and genetic evaluation, as is the case in Australia. The aim of this study was to estimate variance components for novel calf traits using a data set that was co-designed with farmers and included calf identity, calving ease, health records and genotypes. Almost 20,000 calf records from over 50 farms located throughout Australia were collected between 2020 and 2023. In Holstein calves, the mean ± SE prevalence of preweaning mortality (PWM) and scours, were 0.020 ± 0.001 and 0.059 ± 0.002, respectively. A newly defined and subjectively scored trait called Calf Vitality (vitality) was co-developed with farmers, where 21% of calves were classed in the top category of ripper/vigorous, while 54% were good or average, 6% were duds and 19% of scored calves died. Univariate linear models that included a genomic relationship matrix were used to estimate variance components for diseases and vitality, where heritability values were between 1% and 11% in Holsteins depending on the trait. The models included herd-year-season (HYS), sex, parity group and calving ease (Holstein only) as fixed effects and these were found to be significant (P < 0.05 to 0.001) for most breed and trait combinations. The estimated reliability of EBVs ranged between 0.2 and 0.3. In Australia, Holsteins are more numerous than the Jersey breed, and so despite efforts to compile an appropriate data set, the disease prevalence and record numbers were too low to report genetic variance for calf health traits in the Jersey breed. Approximate genetic correlations with other calf health traits such as stillbirth (SB) and PWM were modest but favorable. There were few significant correlations with lactating cow traits (such as survival, somatic cell count and likeability) and national selection indexes that are routinely evaluated in Australia and those that were significant were in a favorable direction.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727235","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":"Quantification and Metabolic Variations of Mycotoxins in Raw Milk: Implications for Dairy Cow Health and Human Safety.","authors":"Yuanyuan Chen, Jiaxin Cheng, Zhuangshu Wang, Honglin Liu, Cheng Xia, Haifeng Zhang, Siqi Zou, Qiaocheng Chang, Chuang Xu","doi":"10.3168/jds.2024-25395","DOIUrl":"https://doi.org/10.3168/jds.2024-25395","url":null,"abstract":"<p><p>This study established a method using ultra-performance liquid chromatography tandem mass spectrometry for the quantitative analysis of 9 harmful mycotoxins: Zearalenone (ZEN), α-Zearalanol (α-ZEA), HT-2 Toxin (HT-2), T-2 Toxin (T-2), Ochratoxin A (OTA), Fumonisin B1 (FB1), Deoxynivalenol (DON), Aflatoxin M1 (AFM1) and Aflatoxin B1 (AFB1) in raw milk. The method exhibited good linearity, sensitivity, accuracy, and precision, making it suitable for trace analysis of these toxins in raw milk. We applied this method to analyze 200 raw milk samples from Heilongjiang province, China, and found that they contained multiple mycotoxins, with a relatively high concentration of ZEN. To further explore the metabolism of these mycotoxins in dairy cows, we conducted a metabolic study on 12 lactating dairy cows. The results showed significant metabolic changes among the 9 mycotoxins, with ZEN demonstrating notably higher metabolic conversion rates compared with other mycotoxins in the transitions from feed to serum, from feed to milk, and from feed to feces. These findings provide new insights into the safety of raw milk and emphasize the importance of strict monitoring and regulation of these toxins in dairy products to protect human health. Simultaneously, we believe that future research should delve deeper into the metabolism of mycotoxins in dairy cows, which is crucial for ensuring public health safety.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727079","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":"Prevention of osteoporosis in ovariectomized mice with yak caseinate calcium.","authors":"Lijing Yang, Haiyun Zhou, Qianyu Wang, Ziheng Wang, Lin Bai, Jia Wei, Li Song, Fumei Zhang, Xiaojing Tian, Tisong Liang","doi":"10.3168/jds.2024-25711","DOIUrl":"https://doi.org/10.3168/jds.2024-25711","url":null,"abstract":"<p><p>Moderate calcium supplementation coupled with enhanced calcium absorption rates in postmenopausal women is crucial for the prevention of postmenopausal osteoporosis (PMOP). Here, calcium yak caseinate (CYC) was provided to ovariectomized (OVX) mice as a nutrition supplement for 6 wk and was shown to effectively improve PMOP. It was observed that CYC remarkably improved the bone physical index (bone length and weight) of OVX mice, and significantly reduced the levels of serum calcium, alkaline phosphatase (ALP), and carboxy-terminal telopeptide of type I collagen, while significantly increasing the level of serum procollagen I N-terminal propeptide. It is of particular significance that low-dose CYC (L-CYC) was observed to prevent the decline of bone mineral density (BMD) in OVX mice. Moreover, CYC supplementation has been shown to attenuate the deterioration of trabecular bone structure and to maintain the morphology and number of trabeculae. Additionally, it has been demonstrated to prevent skeletal muscle atrophy to a certain extent. This study indicated that L-CYC effectively inhibited bone resorption while facilitating bone formation, thereby improving bone quality in OVX mice.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143727142","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}