Journal of Dairy Science最新文献

{"title":"Cullin 3 mitigates nonesterified fatty acid–induced oxidative stress in mammary epithelial cells: Involvement of BCL2/BECN1 and autophagy","authors":"Yifei Dong ,&nbsp;Wenwen Gao ,&nbsp;Kai Liu ,&nbsp;Cai Lin ,&nbsp;Muhammad Usman ,&nbsp;Juan J. Loor ,&nbsp;Guojin Li ,&nbsp;Liguang Cao ,&nbsp;Zifeng Yang ,&nbsp;Jianchun Luo ,&nbsp;Depeng Li ,&nbsp;Qianwen Sun ,&nbsp;Lin Lei ,&nbsp;Xiliang Du ,&nbsp;Yuxiang Song ,&nbsp;Guowen Liu ,&nbsp;Xinwei Li","doi":"10.3168/jds.2024-25879","DOIUrl":"10.3168/jds.2024-25879","url":null,"abstract":"<div><div>High nonesterified fatty acid (NEFA) concentrations in cows with clinical ketosis lead to metabolic dysfunction in mammary cells, resulting in oxidative stress. Studies have shown that autophagy is impaired in the mammary glands of ketotic cows, and enhancing autophagy mitigates oxidative stress in these animals. Cullin 3 (CUL3), an E3 ubiquitin ligase, is integral for maintaining cellular homeostasis, particularly regulation of oxidative stress and autophagy. Whether CUL3 is involved in mitigating NEFA-induced oxidative stress is unknown. This study aimed to investigate the protective effects and underlying mechanisms whereby CUL3 mitigates NEFA-induced oxidative stress in mammary epithelial cells. First, mammary gland tissue and blood samples were collected from healthy cows (n = 12, BHB &lt;0.6 m<em>M</em>) and cows with clinical ketosis (n = 12, BHB &gt;3.0 m<em>M</em>). Compared with healthy cows, cows with clinical ketosis had reduced productive performance, decreased CUL3 expression, impaired autophagic activity, and increased oxidative stress status in mammary tissue. In vitro, incubating the immortalized bovine mammary epithelial cell line (MAC-T) with 1.2 m<em>M</em> NEFA downregulated CUL3 expression, impaired autophagy, and increased oxidative stress. Adenovirus-mediated overexpression of CUL3 attenuated NEFA-induced accumulation of peroxides and reactive oxygen species, whereas silencing of CUL3 via small interfering RNA exacerbated these effects. Even when nuclear factor erythroid 2 related factor 2 (NFE2L2) expression was reduced by overexpression of CUL3, there was no worsening of NEFA-induced reductions in mRNA levels of NFE2L2 downstream target genes (NADPH quinone oxidoreductase 1 [<em>NQO1</em>], heme oxygenase-1 [<em>HMOX1</em>], glutamate-cysteine ligase catalytic subunit [<em>GCLC</em>)], and glutamate-cysteine ligase modifier subunit [<em>GCLM</em>]). The reduction in NEFA-induced oxidative stress by CUL3 was diminished upon autophagy related 5 (ATG5) silencing suggesting that CUL3 alleviates NEFA-induced oxidative stress via autophagy. Additionally, CUL3 overexpression aggravated the NEFA-induced decrease in BCL2 apoptosis regulator (BCL2) expression along with alleviating the NEFA-induced decrease in Beclin1 (BECN1) expression. Under NEFA treatment, overexpression of BCL2 partly mitigated the CUL3-induced elevation in BECN1. Overall, oxidative stress and impaired autophagy are characterized in the mammary tissue of cows with clinical ketosis. CUL3 activation, likely through the BCL2-BECN1 pathway, enhances autophagy and mitigates NEFA-induced oxidative stress in MAC-T cells. Thus, targeting CUL3-mediated autophagy could be a promising therapeutic strategy to reduce oxidative stress-induced damage in bovine mammary epithelial cells.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 4163-4179"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584112","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":"Dairy Foods: A Matrix for Human Health and Precision Nutrition—Introduction","authors":"G.E. Lewis","doi":"10.3168/jds.2024-25185","DOIUrl":"10.3168/jds.2024-25185","url":null,"abstract":"","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3068-3069"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143833795","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":"Factors associated with the evolution of digit health in Swiss dairy herds in a nationwide digit health program","authors":"Analena Sarbach ,&nbsp;Jens Becker ,&nbsp;Claudia Syring ,&nbsp;Andreas Fürmann ,&nbsp;Maria Welham Ruiters ,&nbsp;Anke Regli ,&nbsp;Jim Weber ,&nbsp;Adrian Steiner","doi":"10.3168/jds.2024-25124","DOIUrl":"10.3168/jds.2024-25124","url":null,"abstract":"<div><div>The purpose of this study was to investigate the evolution of digit health (DH) on Swiss dairy farms participating in a nationwide DH program and to identify risk factors associated with poor DH. Specially trained claw trimmers recorded disorders of the digits electronically during routine trimmings between January 2020 and June 2023. The first part of the study was a nonrandomized controlled implementation study, comparing the evolution of DH in 75 herds that received professional on-farm risk assessments, as well as veterinary advice with 49 herds that did not. Overall DH improved over time in both groups, with no difference between the groups. Differences emerged when implementation rates of measures after on-farm risk assessment were considered: DH of farms implementing &gt;50% of recommended measures improved significantly more compared with farms implementing ≤50%. Also, farms where cows predominantly suffered from infectious-related lesions improved significantly compared with farms where cows suffered predominantly from mechanical–metabolic-related lesions. The second part of the study consisted of a retrospective observational risk factor analysis with a larger population (498 farms). Here, greater improvement of DH on a farm over the study period was associated with a higher farm claw score (index for decreased DH) at the beginning of the study and longer duration of participation in the DH program. Moreover, less improvement of DH was associated with freestalls, with “valley area” farm sites, and with herds with Holstein Friesian cows as predominant breed. Our results suggest that, if implemented appropriately, measures issued by DH experts may improve DH. Furthermore, voluntary participation in a DH program in combination with routine electronic recording of DH data by claw trimmers seem to raise farmers' motivation to improve DH. Our results are useful for farmers and veterinarians as well as for establishing DH programs in other countries.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3965-3979"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142941542","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":"Dairy Foods: A Matrix for Human Health and Precision Nutrition—The impact of the dairy food matrix on digestion and absorption","authors":"David W. Everett","doi":"10.3168/jds.2024-25682","DOIUrl":"10.3168/jds.2024-25682","url":null,"abstract":"<div><div>The nutritional value of any food product has historically been measured by the calorific value of individual components, harking back to the days of the development of the bomb calorimeter. A fuller understanding of nutrition later took into account the need for specific components, such as proteins, carbohydrates, vitamins and minerals, that are known to be required for good human health and growth. In milk and milk products, these include casein and whey proteins, lactose, milk fat triacylglycerides, minor lipid components (both charged and neutral), calcium, and micronutrients. Whey proteins are known to be richer in EAA, compared with casein, and also to contain branched chain amino acids for muscle growth. Calcium is found in the form of the calcium phosphate mineral and is dispersed, but largely insoluble, in milk. All of this information does not take into account interactions between milk components, and therefore can be considered as a reductionist nutritional approach. This review takes a structural and physical chemical approach to understand how digestibility and nutritional delivery is affected by microstructures and nutrient component interactions, with a focus on mechanistic explanations.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3070-3087"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942041","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":"Modeling the effects of heat stress on production and enteric methane emission in high-yielding dairy herds","authors":"L. Chen,&nbsp;V.M. Thorup,&nbsp;S. Østergaard","doi":"10.3168/jds.2024-25460","DOIUrl":"10.3168/jds.2024-25460","url":null,"abstract":"<div><div>Given global warming and the growing dairy cow population, heat stress in dairy herds is of increasing concern. During heat stress, dairy cows suffer from compromised productivity and animal welfare in terms of reduced feed intake and milk production, decreased reproductive performance, and generally increased risk of health problems. These effects and their interactions are complex and are usually quantified separately; thus, a comprehensive understanding of the herd-level performance is missing. Moreover, compromised animal welfare and productivity may impact enteric methane (CH₄) emission; however, these effects have rarely been investigated. Therefore, by performing herd simulation, this study aimed to model the impact of heat stress on dairy production and enteric CH₄ emissions by aggregating its effects on milk production, reproduction, and health. Specifically, 10 scenarios (including baseline) were simulated in a conventional, high-yielding Danish herd by incorporating different combinations of effects on milk production, reproduction, and health of heat stress in different exposure durations (1, 2, and 4 mo). Sensitivity analyses were further conducted to account for the effects of different reduction rates in feed efficiency (kg ECM/kg DMI). Results showed that heat stress decreased the herd-level milk yield by up to 8.6% if all effects were combined in a duration of 4 mo, whereas a direct effect on milk yield only decreased herd-level yield by up to 6.9%. Heat stress increased the herd-level enteric CH₄ intensity ranging from 0.8% to 6.6% across all 9 scenarios as compared with the baseline scenario. When a reduction in feed efficiency by 19.2% was assumed, the herd-level CH₄ intensity increased by up to 4.4% during 2 mo. Overall, our results showed large impacts of heat stress on both dairy production and CH₄ emissions and suggest the need to implement management mitigation strategies in heat-stressed dairy herds.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3956-3964"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942174","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":"Diet supplementation with a mixture of essential oils: Effects on enteric methane emissions, apparent total-tract nutrient digestibility, nitrogen utilization, and lactational performance","authors":"C. Benchaar ,&nbsp;F. Hassanat","doi":"10.3168/jds.2024-25447","DOIUrl":"10.3168/jds.2024-25447","url":null,"abstract":"<div><div>This study examined the effects of supplementing dairy cows with a mixture of essential oils on enteric CH₄ emissions, apparent total-tract nutrient digestibility, N utilization, and lactational performance (production, components, and efficiency). Thirty-two multiparous lactating Holstein cows were used in a randomized complete block design. Cows averaged (mean ± SD) 95 ± 15.4 DIM, 47.7 ± 4.51 kg milk yield, and 698 ± 68.2 kg BW at the start of the experiment. The experiment consisted of a 3-wk pretreatment period (i.e., covariate), followed by a 3-wk adaptation to the experimental treatments, and a 10-wk period for data and sample collection. At the beginning of the study, milk yield and DIM data were used to block the cows into 16 blocks of 2 cows each. Subsequently, the blocks were adjusted based on milk yield and enteric CH₄ emission data collected during the pretreatment period. Within each block, cows were assigned to 1 of 2 dietary treatments: (1) a basal diet supplemented with a placebo (control, no additive), or (2) a basal diet with the essential oil supplement (Agolin, 1 g/cow per day). The basal diet (i.e., TMR) was composed of 69.3% forage (corn and alfalfa silage and grass hay) and 30.7% concentrate, on a DM basis, and the essential oil mixture consisted mainly of coriander seed oil, eugenol, geraniol, and geranyl acetate. Twice daily, the essential oil supplement was thoroughly mixed with 50 g of a commercial protein supplement (i.e., carrier) and 500 g of the TMR and this premix (i.e., 550 g/meal) was offered to the cow before the basal diet. No interactions between the essential oil supplement and the sampling week were observed for any of the response variables. Dry matter intake, apparent total-tract nutrient digestibility and N balance were unaffected by feeding the essential oil supplement. Yields of milk, 4% FCM, and ECM were not modified by the experimental treatment. Neither feed efficiency (kg milk/kg DMI, kg 4% FCM/kg DMI, kg ECM/kg DMI) nor dietary N use efficiency in milk N secretion (i.e., g milk N/g N intake) were affected by essential oil supplementation. Body weight change and BCS did not differ between cows fed the essential oil supplement versus cows fed the control. Daily enteric CH₄ production, CH₄ yield, and CH₄ intensity averaged 498 g/d, 18.4 g/kg of DMI, and 11.0 g/kg of ECM, respectively, and were unchanged by essential oil supplementation. We conclude that supplementing cows fed a high-forage diet with 1 g/d of this essential oil mixture did not positively affect lactational performance, nutrient digestibility, and N utilization, or reduce enteric CH₄ (production, yield, and intensity). More research is needed to identify the optimal dose of this essential oil mixture and elucidate how it may interact with the basal diet to improve the mixture's efficacy.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3560-3572"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142942256","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":"Bovine fecal extracellular vesicles: A novel noninvasive tool for understanding gut physiology and pathophysiology in calves","authors":"Chanaka Premathilaka ,&nbsp;Suranga Kodithuwakku ,&nbsp;Getnet Midekessa ,&nbsp;Kasun Godakumara ,&nbsp;Qurat Ul Ain Reshi ,&nbsp;Aneta Andronowska ,&nbsp;Toomas Orro ,&nbsp;Alireza Fazeli","doi":"10.3168/jds.2024-25920","DOIUrl":"10.3168/jds.2024-25920","url":null,"abstract":"<div><div>Dairy calf gut health is linked with development and future production. Fecal extracellular vesicles (fEV) have emerged as a noninvasive tool in elucidating gut physiology and pathophysiology. Because feces is a complex matrix, the enrichment of extracellular vesicles (EV) from ruminant or preruminant feces is difficult. Nevertheless, if enriched, they have great potential as a gut health diagnostic and monitoring tool in dairy calves. Therefore, this study aimed to devise a protocol to enrich and characterize fEV from preweaning calves. We developed an fEV enrichment method by combination of differential centrifugation and double size exclusion chromatography and then characterized the fEV from the healthy calves. The study also assessed sample storage conditions, and the results indicated that storing preprocessed fecal samples at −80°C effectively preserves EV without introducing additional nanoparticles. Finally, fEV from 10-d-old healthy and <em>Cryptosporidium</em> spp.-positive calves were enriched, and a comparative analysis of fEV characteristics between the 2 groups was performed. Characterization results on EV specific protein biomarkers, size profile, total protein content, zeta potential, and morphology clearly established the enrichment of fEV with the developed protocol. The fEV analysis for calves positive and negative for <em>Cryptosporidium</em> spp. revealed a significant decrease in average nanoparticle size and zeta potential values in <em>Cryptosporidium</em> spp.-infected calves. Furthermore, the enriched fEV carried protein and nucleic acid cargo which could be further analyzed for other biomarkers to predict the gut physiology and pathophysiology of calves. In conclusion, our study has successfully optimized a protocol to enrich high purity grade EV from calf feces and displayed potential diagnostic application as a noninvasive tool.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 4116-4130"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073133","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":"Graduate Student Literature Review: Organic dairy cattle longevity and economic implications—Contemporary perspectives*","authors":"B. Shrestha ,&nbsp;S. Paudyal ,&nbsp;K. Kaniyamattam ,&nbsp;Y.T. Grohn","doi":"10.3168/jds.2024-25767","DOIUrl":"10.3168/jds.2024-25767","url":null,"abstract":"<div><div>Although conventional production systems have been studied extensively, limited research exists on the longevity of organically raised dairy cows. The objective was to discuss the factors affecting dairy cattle longevity and to conduct an economic assessment for prolonged longevity of organic dairy cattle. A dynamic programming tool was adopted for a typical organic and conventional dairy farm in Texas to determine optimal replacement decisions for organic dairy cattle based on the retention pay-off (RPO) value. The model included milk price, calf value, replacement heifer costs, veterinary expenses, financial losses at disposal, insemination, feed, carcass weight, and the discount rate, with representative values for the year 2024. Herd-level inputs (average herd milk production per year per cow, birth weight, adult dairy cow weight, length of voluntary waiting period, estrus detection rate, conception rate, and age at first calving) were extracted from an on-farm herd management software program. The result illustrated that economic benefits and RPO values for pregnant and open cows vary by lactation stage and number. Pregnant cows have higher RPO values than open cows in both systems. On organic farms, pregnant cows' RPO values range from −$110 to $3,373, whereas open cows' values range from −$109 to $1,681 based on the production level and lactation. The RPO for all of the lactation, pregnancy, and production level combinations were higher for organic systems. The average difference in RPO between 2 systems ranged from $1,000 to $200 for lactations 1 and 12, respectively, with organic farms exhibiting higher RPO in 805 out of 900 scenarios, favoring longer productive life in organic dairy farms. In conclusion, optimizing productive lifespan of dairy cows through dynamic culling decisions can lead to increased profitability for organic herds, which, in our analysis, was higher than that of conventional herds.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3734-3745"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073362","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":"Seasonal effects on growth, digestibility, and metabolism of preweaning dairy calves in the southeastern United States","authors":"Ansley M. Roper ,&nbsp;Ruth M. Orellana Rivas ,&nbsp;Jing Gao ,&nbsp;Thiago N. Marins ,&nbsp;C.G. Savegnago ,&nbsp;Thalyane Rodrigues ,&nbsp;Victor H.L.R. Melo ,&nbsp;Diego Ferreira de Araújo ,&nbsp;Juliana Goncalves de Souza ,&nbsp;Pedro Melendez ,&nbsp;John K. Bernard ,&nbsp;Sha Tao","doi":"10.3168/jds.2024-25938","DOIUrl":"10.3168/jds.2024-25938","url":null,"abstract":"<div><div>The aim of the current study was to evaluate seasonal effects on growth, digestibility, and metabolism of dairy calves in Georgia. Holstein calves (n = 48 per season) were enrolled at 7 d of age (DOA) from June to Aug (defined as summer, BW = 40 ± 4 kg) and from Nov to Jan (defined as winter, BW = 42 ± 4 kg). Similar general management and feeding practices were applied to calves in both seasons. Calves were housed in individual polyethylene hutches with sand bedding. Starting at 2 DOA, calves were fed a milk replacer (MR) containing 26% protein and 17% fat (0.65 or 0.76 kg of DM/d and mixed with warm water to reach 12.5% solids) and calf starter (CS) was offered ad libitum. Weaning began at 43 DOA by reducing MR 50% until 49 DOA when MR feeding ceased. Calves remained enrolled until 63 DOA. Calf starter intake was recorded daily. Ambient temperature (AT) and relative humidity (RH) were recorded hourly. Rectal temperature and respiration rate were assessed 3×/wk and BW was measured weekly. Blood was collected to analyze metabolites and insulin at 3, 7, 14, 21, 28, 35, 42, 49, 56, and 63 DOA. The apparent total-tract digestibility of nutrients was measured during both the pre- (14.9–17.9 DOA) and postweaning (51.0–54.0 DOA) periods. The MIXED procedure of SAS was used to analyze repeated measures data. Season, time, and their interactions were included as the fixed effects. The CV of hourly AT or RH within a day was calculated as a proxy of within-day variation. The CV of daily average AT or RH within a week was used as the proxy of day-to-day variation. Linear regression analysis between ADG and environmental parameters was performed using the GLM procedure. Summer months had greater AT (27°C vs. 13°C) but similar RH (83% vs. 81%) relative to winter months, respectively. Rectal temperature and respiration rate were higher during the summer compared with winter. Season had no effect on CS intake before weaning, but summer calves had greater CS intake at 9 wk of age compared with winter calves. No seasonal effect was observed for BW, but summer calves had greater ADG at 3, 5, and 9 wk of age. A negative relationship (R² = 0.11) between preweaning ADG and within-day AT variation was observed during winter, whereas during the summer day-to-day AT variation was negatively associated with preweaning ADG (R² = 0.06). Compared with calves raised during winter, calves raised in summer had lower apparent total-tract digestibility of DM, OM, and CP during the preweaning period. Furthermore, summer calves had lower circulating glucose before and after weaning and lower blood BHB concentrations following weaning compared with calves raised in winter. In conclusion, in Georgia, the within-day and day-to-day AT variations affect preweaning calf growth, and calves raised during summer had lower nutrient digestibility and altered metabolism relative to calves raised in winter.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 4318-4331"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143073368","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":"Fermentation characteristics of Lactobacillus helveticus 3-4 and Kazachstania unispora A-3 complex starter: Enhancing the fermentation performance and flavor of koumiss","authors":"Yanan Xia ,&nbsp;Weigang Miao ,&nbsp;Jianjun Zhao ,&nbsp;Yongfu Chen","doi":"10.3168/jds.2024-26002","DOIUrl":"10.3168/jds.2024-26002","url":null,"abstract":"<div><div>The flavor development of koumiss is intricately linked to its starter culture. This research aimed to delve into the microbial diversity of mare milk and koumiss, isolate the dominant lactic acid bacteria (LAB) and yeast, and assess the effects of composite strains on the fermentation characteristics and flavor quality of koumiss. In mare milk, the dominant microbial genera were <em>Enterobacter</em> and <em>Rhodotorula</em>. As fermentation progressed, the microbial diversity of mare milk gradually declined, and <em>Lactobacillus</em> and <em>Dekkera</em> became the dominant bacterial genera. A total of 42 LAB types and 24 yeast types were isolated. A 1:1 combination of <em>Lactobacillus helveticus</em> 3-4 and <em>Kazachstania unispora</em> A-3 led to a high viable bacterial count and rapid acid production in koumiss. Twenty-one flavor substances were detected, endowing the koumiss with intense umami and sour profiles. This study offers a theoretical foundation for the development and industrial application of koumiss starters.</div></div>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":"108 4","pages":"Pages 3455-3467"},"PeriodicalIF":3.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143476030","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}