Journal of Dairy Science最新文献

{"title":"Effects of postgrazing sward height on individual and per-hectare milk production of supplemented high-producing dairy cows.","authors":"Gabriel Menegazzi, Carolina Dorao, Cecilia Loza, Daniel Talmón, Diego A Mattiauda, Teresa Cristina M Genro, Walter J J Gerrits, Jan Dijkstra, Pablo Chilibroste","doi":"10.3168/jds.2025-26767","DOIUrl":"https://doi.org/10.3168/jds.2025-26767","url":null,"abstract":"<p><p>Residual sward height management is a key factor influencing milk production and grazed forage utilization per cow and per hectare in pasture-based dairy systems. This study evaluated the effects of postgrazing sward height on forage growth rate and DMI, milk production, and BCS in supplemented, high-producing dairy cows. The study captured cumulative treatment effects on animal performance across nearly an entire lactation, as well as sward dynamics over most of the tall fescue growing season. Thirty-two multiparous Holstein cows were assigned to 2 treatments: the control treatment, with a postgrazing sward height of 5.0 to 7.0 cm (CT), and the high treatment, with a postgrazing sward height of 12.0 to 15.0 cm (HI). The study spanned 215 d of grazing on a Lolium arundinaceum sward in a randomized complete block design, with 4 blocks, each measuring 3.2 ha, and consisted of 2 paddocks, each measuring 1.6 ha. Cows had one grazing session between milkings and were supplemented with a mixed ration in the opposite session. Rotational grazing was employed, with new strips allocated once the postgrazing sward height for each treatment was achieved. A new grazing cycle was initiated when plants reached the 2.5 to 3.0-leaf phenological state. Any extra or unused areas within a grazing cycle were always recorded. The postgrazing sward heights were 7.7 and 14.4 cm for the CT and HI treatment, respectively. Forage growth rate tended to be 21% higher in the HI treatment (40 vs. 33 kg DM/ha per day), and cows stayed longer per strip (3.9 vs. 2.9 d) and had 2.5 times more grazing cycles (8.3 vs. 3.3). Total forage disappearance was similar between treatments. Cows in the HI treatment had greater individual grazed forage DMI (+2.0 kg/cow) and BCS throughout lactation compared with CT cows. The HI treatment also increased the individual milk production by 10% (31.5 vs. 34.5 kg milk/d) while reducing concentrate intake per unit of milk by 10%, resulting in a tendency for higher income over feed costs at cow level. However, although we observed a tendency for a higher forage growth rate, this approach required a larger grazing area (1.18 vs. 1.60 ha/4 cows), leading to a trend toward 21% lower milk output per hectare (23,598 vs. 18,528 kg milk/ha). In contrast, the CT treatment supported a higher stocking rate but resulted in lower grazed forage DMI, higher supplemental feed input per hectare and slower BCS recovery. These findings highlight the importance of aligning grazing strategies with system-specific goals. Farmers seeking to maximize land productivity may favor lower postgrazing sward heights, although these must be managed carefully to prevent adverse effects on animal health, reproduction, and long-term productivity due to slower BCS recovery during lactation and lower BCS at the onset of dry off. Conversely, systems aiming to reduce feed costs may benefit from a higher residual sward height, which enhances individual cow performance and BCS while ","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102556","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":"Prepartal liver glutathione and its association with lactation performance, metabolism, and health outcomes in transition dairy cows.","authors":"A F S Lima, M H De Oliveira, G G Begalli, R C B Grazziotin, J Halfen, E Trevisi, J S Osorio","doi":"10.3168/jds.2025-26916","DOIUrl":"https://doi.org/10.3168/jds.2025-26916","url":null,"abstract":"<p><p>Our objective was to determine the association of prepartal liver glutathione (GSH) concentration with lactation performance parameters, metabolism and inflammation, and gene expression in transition dairy cows. Sixty Holstein dairy cows were enrolled at -21 ± 3.3 d relative to calving and remained on trial until 30 DIM. All cows received the same close-up diet from -21 DIM until calving (1.67 Mcal/DM and 13.5% CP) and lactation diet from calving until 30 DIM (1.80 Mcal/DM and 17.7% CP). A liver biopsy was performed in all cows at -8 d (±3.2 d) relative to calving, and total GSH was measured using a commercial colorimetric kit. This metric was used to retrospectively classify cows by GSH as high (HGSH; n = 15), medium-high (MHGSH; n = 15), medium-low (MLGSH; n = 15), and low (LGSH; n = 15). Liver samples were collected at -8, 7, and 21 DIM, and blood samples at -21, -10, 2, 7, 14, and 21 DIM to evaluate oxidative stress, metabolism, inflammation, and liver function biomarkers. Statistical analysis was performed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) with the preplanned contrast to test a linear effect with increasing levels of GSH. A linear increase in prepartal energy balance (EB; from -1.55 to 1.11 Mcal/d) and postpartal BCS (from 3.00 to 3.16) was observed as prepartal liver GSH increased from LGSH to HGSH groups, suggesting an association between prepartal liver GSH and energy metabolism around parturition. This effect was also associated with a trend for a linear increase in prepartal DMI as prepartal liver GSH increased across groups. We observed a linear increase in ECM (from 50.2 to 54.7 kg/d) and milk protein yield (from 1.33 to 1.46 kg/d) as prepartal liver GSH levels increased. Neither reactive oxygen metabolites nor antioxidant capacity measured via ferric reducing antioxidant power were altered according to prepartal liver GSH. However, there was a linear increase in the total thiol groups of plasma as prepartal liver GSH increased, suggesting some level of antioxidant protection. A linear increase in total (from 0.83 to 1.74 nmol/mg), reduced (from 0.66 to 1.37 nmol/mg), and oxidized forms of GSH (from 0.07 to 0.17 nmol/mg) was observed in the liver as prepartal liver GSH levels increased. The hepatic activity of g-glutamyl transpeptidase at -8 DIM was greater in MHGSH cows compared with LGSH and HGSH. At -8 DIM, a linear upregulation of genes related to GSH metabolism, including GCLC, GGCT, and GSR, was observed as prepartal liver GSH increased, suggesting that transcriptional regulation may contribute to the GSH phenotype observed in this study. These results emphasize the importance of maintaining adequate hepatic GSH reserves before calving to support metabolic adaptation and lactation performance. Future research should explore the direct effect of GSH on lactation performance and oxidative stress protection, as well as nutritional and management factors to enhance hepatic GSH synthesis before cal","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102576","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":"The effects of inclusion level of an extruded flaxseed-pea supplement on nitrogen balance and flow of amino and fatty acids in a dual-flow continuous culture system.","authors":"J R Vinyard, G Salas Solis, M L Johnson, A C Silva Vicente, M Siregar, E Sarmikasoglou, C Hammond, S W Ma, L Girardin, B Kelln, R Dreger, A P Faciola","doi":"10.3168/jds.2025-26735","DOIUrl":"https://doi.org/10.3168/jds.2025-26735","url":null,"abstract":"<p><p>Omega-3 fatty acids (FA) have well-established benefits in human health, including anticarcinogenic and cardioprotective effects. This has prompted growing interest in enriching dairy products with n-3 FA through dietary manipulation in dairy cows. The objective of this study was to evaluate the effects of increasing dietary inclusion of linPRO-R (LIN), a proposed rumen-protected matrix of flaxseed and field pea proteins (21% fat, 24% CP, 10.07% n-3 FA; DM basis), on N metabolism, AA flow, and long-chain FA outflow using a dual-flow continuous culture system. Treatments consisted of 4 levels of LIN inclusion (0%, 2.5%, 5.0%, and 7.5% of diet DM) in a TMR, replacing portions of dried distillers grains and calcium salts of long-chain FA to maintain similar CP and ether extract levels across treatments. The study followed a replicated 4 × 4 Latin square design using 8 fermenters across four 10-d periods (7 d adaptation, 3 d sampling). Effluent samples were collected at 3, 6, 9, and 24 h after feeding and analyzed for AA, N balance, and long-chain FA concentrations. Data were analyzed using GLIMMIX procedure of SAS with fixed effects of treatment, period, and square, with fermenter nested within square as a random effect. Inclusion of LIN had no effect on AA flow, N flow, or calculations of RDP, RUP, or bacterial N efficiency. However, increasing dietary LIN reduced the outflow of SFA (notably C16:0) and increased the outflow of C18:3n3 (0.48%-3.47% of total FA), despite an increase in the biohydrogenation (93.4%-95.9%). These results suggest that LIN can enhance the delivery of n-3 FA postruminally, despite a large fraction of the FA being biohydrogenated, without impairing N metabolism or AA availability, supporting its use as a dietary strategy to increase the nutritive value of dairy products.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145102606","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":"Quantitative model predicts implementing school cafeteria share tables will not compromise milk safety.","authors":"Gabriella Pinto, Yiyi Li, Melissa Pflugh-Prescott, Matthew J Stasiewicz","doi":"10.3168/jds.2025-27069","DOIUrl":"https://doi.org/10.3168/jds.2025-27069","url":null,"abstract":"<p><p>School cafeteria share tables can address food waste and improve food security by allowing students to share unopened items, such as milk. However, unresolved safety concerns present a barrier to recovering milk cartons on share tables. We adapted our previous share table model to study Listeria monocytogenes in pasteurized milk, assuming a concentration distribution that reflects the realistically low prevalence of the pathogen. Student sharing behavior was simulated for 50 years of school weeks (5 d/wk over 37 wk/yr). Milk safety is assessed by quantifying (1) time to L. monocytogenes growth of 1 log₁₀, (2) L. monocytogenes concentration at consumption, and (3) listeriosis risk. We compare these measures across 23 what-if scenarios to identify potential risk factors and mitigation strategies. Under the baseline scenario (with no share table temperature management), L. monocytogenes increases by 1 log₁₀ after 1 reservice (after service 2). With share table temperature management, improved overnight refrigeration, or shorter services, L. monocytogenes did not increase by 1 log₁₀ until after 2 d of reservice (after service 3). Under excessive time-temperature abuse (inadequate overnight refrigeration or long services), L. monocytogenes increases by 1 log₁₀ before the first day of reservice (before service 2). Comparing the baseline scenarios of share table and no share table, L. monocytogenes concentration at consumption did not substantially differ. Importantly, L. monocytogenes concentration at consumption never exceeded 100 cfu/mL, except under the longest (266 min) service scenario, for only 0.0006% of milk cartons (11/1,794,887). The mean probability of illness per serving (P_Illness) was low across all scenarios. Comparing the baseline share table and no share table scenarios, P_Illness was 3.32 × 10^-13 and 2.72 × 10^-13, respectively, translating to 1 listeriosis illness in every 2,100 (2,000-2,400) and 3,000 (2,700-3,400) years across all public schools in the United States. These results demonstrate the extremely small predicted risk of listeriosis from consuming milk cartons in cafeterias with share tables, providing an evidence base to support school nutrition staff in conversations with health departments during the approval of share table management practices.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058160","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":"Association between the severity of subacute ruminal acidosis and the microbiome of the rumen, and the metabolome of the rumen, blood, and milk in primiparous cows.","authors":"Ezequias Castillo-Lopez, Thomas Hartinger, Sara Ricci, Kangkang Xu, Heidi E Schwartz-Zimmermann, Franz Berthiller, Nicole Reisinger, Qendrim Zebeli","doi":"10.3168/jds.2025-27008","DOIUrl":"https://doi.org/10.3168/jds.2025-27008","url":null,"abstract":"<p><p>Cows have been shown to develop different severities of SARA when fed the same diet. In the present study, we used 24 Holstein dairy cows to investigate the association between SARA severity and the ruminal microbiome as well as the metabolomes of the rumen, blood, and milk from 21 d before parturition until 70 DIM. The dietary concentrate was increased from 32% to 60% (DM basis) during the first week of lactation. Based on the severity of SARA, 3 groups were compared: high, moderate, and low severity. Relative to parturition, the rumen microbiome and metabolome were analyzed on d -21, 14, 28, and 56; blood metabolome was analyzed on d -21, -7, 1, 3, 7, 10, 14, 21, 28, 42, 56, and 70, and milk metabolome was analyzed on d 1, 3, 7, 14, 21, 56, and 70. Statistical analysis of the metabolome was performed with MetaboAnalyst v. 6.0; and statistical analyses for microbial abundance data were conducted in R using Maaslin2 package. Rumen microbial abundance profile was not associated with the SARA severity, but several amylolytic acid tolerant genera (i.e., Acidobacteria and Lactobacillus) were found only within the high SARA group. In addition, the transition to the lactation diet decreased fibrolytic bacteria and increased amylolytic and proteolytic bacteria (P < 0.05). In the ruminal metabolome, High SARA was associated with greater levels of nucleotides, nitrogen compounds, and pyrimidine derivatives as well as enrichment of metabolic pathways for nitrogen and AA metabolism (P < 0.05). In the blood metabolome, High SARA was associated with greater levels of cholesterol esters, phosphatidylcholines, and enrichment of metabolic pathways for steroid and bile acid biosynthesis (P < 0.05). In the milk metabolome, moderate SARA was associated with greater levels of triglycerides as well as enrichment of metabolic pathways for fatty acid biosynthesis (P < 0.05). The change from pre- to postpartum increased ruminal triglycerides, amino acids, carbohydrates and their derivatives in the rumen, and increased sugars and lipid derivatives in the blood. Milk showed a decrease mainly in triglycerides with increased DIM compared with first day of lactation. Overall, findings from this study reveal differential metabolomic response of dairy cows when fed the same diet. The greatest differences in the cow metabolome among SARA severity groups were observed either around calving or at peak of lactation, likely due to increased nutrient metabolism. High severity of SARA was associated with enriched metabolic pathways for nitrogen and AA metabolism in the rumen, as well as greater steroid biosynthesis, cholesterol esters and phosphatidylcholines in blood. Moderate SARA severity was associated with enrichment of metabolic pathways for fatty acid biosynthesis and triglycerides in milk.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058110","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":"Confinement and pasture-based dairy herds differ in plasma lipid profiles.","authors":"David B Sheedy, Helen M Golder, Sergio C Garcia, Zhiqian Liu, Priyanka Reddy, Simone J Rochfort, Joanne E Hemsworth, Delphine E Vincent, Jennie E Pryce, Ian J Lean","doi":"10.3168/jds.2025-26782","DOIUrl":"https://doi.org/10.3168/jds.2025-26782","url":null,"abstract":"<p><p>Dairy cow housing and management can be broadly described as either intensive house confinement (CONFINE) or extensive pasture-based (PAST) systems. The diets between systems typically differ in their forage base, with CONFINE farms often utilizing maize silage in a TMR. Consequently, the lipid composition of diets differs between systems. The influence of housing system on blood lipidomics is currently unknown, but due to the bioactive role of lipids in influencing overall health and productivity, differences in diet may have consequences for reproduction, health, and aging of cows. The objective of this cross-sectional, multisite study was to investigate blood lipids and metabolites from cows in PAST and CONFINE systems, in the dry period (∼27 d prepartum) and at peak milk (∼58 DIM). After exclusions, blood samples from 303 PAST and 398 CONFINE dry-period cows and 350 PAST and 431 CONFINE peak-milk cows from 15 PAST and 15 CONFINE farms were analyzed. A total of 185 lipid species (including glycerophospholipids, sphingomyelin, and triacylglycerols) were evaluated using targeted liquid chromatography-MS, as were 11 routinely measured metabolites. Dry and peak-milk cohorts were analyzed separately throughout. Lipids and metabolites associated with housing system were selected using a variable stabilization approach that was achieved by calculating the frequency of inclusion in categorical (housing system) penalized models using bootstrapping. Variables were retained if inclusion frequency exceeded a false-positive threshold. Five different statistical models were used with variable stabilization. Dry cows in CONFINE systems had decreased globulin, urea, and glycerophospholipids associated with n-3 fatty acids. The highest total inclusion rates in the dry cohort were phosphatidylcholine (PC; 36:5), which mostly comprises palmitic acid (C16:0) and eicosapentaenoic acid (EPA; 20:5n-3), then phosphatidylethanolamine (PE; 38:5, 16:0/22:5n-3 or 18:0/EPA) and PC(34:3; 16:0/18:3 α-linolenic acid [ALA]). No lipids were increased in more than one stabilized model in CONFINE dry cows. Peak-milk CONFINE cows had increased glycerophospholipids associated with n-6 fatty acids. The highest total inclusion-rate lipids in the peak-milk cohort were phosphatidylinositol (PI; 38:3; 18:0/20:3n-6 dihomo-γ-linolenic acid), PC(34:2; 16:0/18:2 linoleic acid [LA]), PC(40:7; 18:2/22:5n-6), PC(34:1; 16:0/18:1), and PE(34:2; 16:0/LA). The CONFINE peak-milk cows also had decreased PC(34:3; 16:0/ALA). This study identified specific lipids that were strongly associated with housing systems, findings that have not been reported elsewhere. Given the important biological functions of omega fatty acids, the pattern of glycerophospholipids with increased n-6 and decreased n-3 in CONFINE cows may indicate housing systems create different risk profiles for reproduction, health, and aging.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058121","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":"Regulatory effects of sweet potato pericarp polyphenols on protein oxidation in commercial fresh milk.","authors":"Zhenlin Zhang, Yixuan Zhu, Weiwei Cheng, Meihua Hu, Xin Yao, Zhichao Yin, Dong Liu","doi":"10.3168/jds.2025-27049","DOIUrl":"https://doi.org/10.3168/jds.2025-27049","url":null,"abstract":"<p><p>This study explored the regulatory effects of sweet potato pericarp polyphenols on protein oxidation in commercially available fresh milk. Fresh milk samples from brands such as Yili, Mengniu, and Bright Dairy were collected and supplemented with sweet potato pericarp polyphenols. The samples were then stored at 4°C, and analyses were conducted to evaluate the antioxidant indices, protein oxidation products, microbial count, and texture parameters. The free radical scavenging capacities measured by 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt assays, as well as the decline in the total antioxidant capacity, were significantly lower in the treatment group compared with the control group. In addition, the treatment group showed lower carbonyl content, reduced oxidative loss of free sulfhydryl groups, inhibited excessive formation of disulfide bonds, a slower increase in thiobarbituric acid reactive substances values, suppressed protein hydrolysis, improved microbial safety, and enhanced textural stability. Therefore, sweet potato pericarp polyphenol can effectively inhibit protein oxidation in fresh milk, preserve protein structural stability, and enhance antioxidant and textural quality. These findings provide a theoretical basis for their potential application in fresh milk preservatives.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058147","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":"Agents are all you need: Pioneering the use of agentic artificial intelligence to embrace large language models into dairy science.","authors":"E Liu, H Yang, S Sharma, M B van Leerdam, P Niu, M J VandeHaar, M Hostens","doi":"10.3168/jds.2025-26775","DOIUrl":"https://doi.org/10.3168/jds.2025-26775","url":null,"abstract":"<p><p>Large language models (LLM) hold significant promise to transform dairy science by enhancing research interpretation, supporting decision making, and improving knowledge dissemination. However, without proper systematic design, LLM may generate irrelevant or factually inaccurate responses for domain-specific questions. Moreover, most existing LLM and related tools are not tailored to the needs of the dairy domain, limiting their practical application within the field. To demonstrate the feasibility and practical value of embracing LLM in dairy science, we developed a 2-component agentic system: (1) a decision-support chatbot grounded in the Journal of Dairy Science (JDS) for science-backed insights and (2) a natural language interface for interacting with academic models and visualizing prediction results. All publicly available JDS abstracts and associated metadata dating back to 1917 were compiled using the PubMed application programming interface, forming a scientific knowledge base that enables the chatbot to answer user questions. A retrieval-augmented generation framework was implemented to ensure that responses generated by LLaMA (a LLM developed by Meta) were well-grounded in peer-reviewed literature, with the 5 most relevant sources cited alongside each answer. To address questions beyond the coverage of JDS literature, a web search agent was incorporated into the system to retrieve supplementary information from external online sources. Grading agents, powered by Databricks Research Transformer X (DBRX; a LLM developed by Databricks), were incorporated to evaluate the credibility and relevance of LLM-generated content to mitigate the risk of misinformation or hallucinated responses. The second component of the system facilitates natural language interaction with MilkBot, a published Bayesian milk yield prediction model. After users submit questions in plain language, the system converts the question into model parameters for MilkBot, executes the model prediction, and uses the predicted output to generate visualizations. This work demonstrates the capability of LLM to serve as intuitive, user-friendly interfaces for dairy-specific models. To our knowledge, this is the first chatbot prototype that integrates large-scale information from scientific literature, web-based resources, and academic models, along with self-evaluation capability, to provide dairy-specific insights to scholars, consultants, and farmers. However, challenges remain to realize the full value of LLM-assisted decision making, such as the lack of region-specific data to tailor the answers to the local circumstances, the need for more robust measures to protect data security and privacy, and the need to integrate additional functions to enable more comprehensive decision support.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058102","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: Precision nutrition meets cellular insight-The mechanistic role of oleic acid in dairy cow metabolism.","authors":"Ursula Abou-Rjeileh, Kyrstin Gouveia, Adam L Lock, G Andres Contreras","doi":"10.3168/jds.2025-26922","DOIUrl":"https://doi.org/10.3168/jds.2025-26922","url":null,"abstract":"<p><p>Dairy cows going through the transition period experience a state of negative energy balance, driven by a mismatch between rising energy needs and reduced feed intake. Although fat breakdown (i.e., lipolysis) is a necessary adaptation to meet rising energy demands, excessive and prolonged lipolysis can increase disease risk. One strategy to mitigate this gap in energy is by increasing the energy density of the diet through fatty acid (FA) supplementation. Among available FA, oleic acid (OA) has gained attention not only as an energy source, but also for its broader biological effects. This review examines the role of OA in dairy cow metabolism, extending beyond its caloric contribution to its regulatory influence on lipid metabolism, insulin signaling, oxidative stress, and inflammation. We summarize findings from both ruminants and nonruminants to provide mechanistic insights into how OA modulates cellular pathways and contributes to metabolic adaptations, especially within adipose tissue during periods of physiological stress. Additionally, we highlight the nutritional implications of OA on production outcomes such as milk yield and composition, as well as its effects on adipose tissue. By integrating nutritional and mechanistic perspectives, this review provides a comprehensive evaluation of OA potential as a functional nutrient to support health and performance in transition dairy cows.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058139","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 management and technology scenarios on the carbon footprint of milk from pasture-based dairy farm systems.","authors":"Andre M Mazzetto, Shelley Falconer, J Paul Edwards, Chris B Glassey, Mark B Neal, Stewart F Ledgard","doi":"10.3168/jds.2025-26924","DOIUrl":"https://doi.org/10.3168/jds.2025-26924","url":null,"abstract":"<p><p>Consumers are increasingly concerned with their environmental impacts, especially GHG emissions from food production. The main goal of this study was to scope the current and future mitigation practices that can be implemented for pasture-based dairy production, how their effect on emissions could differ by region and farm system and affect long- and short-lived gases differently. To do this, we estimated the total GHG emissions and carbon footprint of milk from New Zealand-average (total of 352 farms) and regional (Canterbury and Waikato) dairy farm systems that rely on grazed pastures for the year 2020 and a projection for 2040 using a cradle to farm-gate life cycle assessment approach. We also simulated a series of mitigation scenarios considering the potential effects of farm management changes and technologies available currently and in the future. For mitigations currently available, the most significant reductions (compared with the baseline 2020 data) occurred by changing the type of brought-in feeds, decreasing stocking rate, and changing manure management. Replacing brought-in feeds that have a high footprint (e.g., imported palm kernel expeller) with maize silage produced locally resulted in a reduction from 5.0% to 19.2% of the footprint (per kg fat and protein-corrected milk). Complete removal of N fertilizer had little effect on the carbon footprint of milk (-0.1% and -0.4%) but was associated with lower production of milk and lower per-hectare GHG emissions (by 9%-11%). The future mitigation that showed the largest potential reduction was the use of methane (CH₄) inhibitors for enteric CH₄ (3-nitrooxypropanol [3NOP] scenario), which is a major source of GHG emissions for dairy grazing systems. This mitigation showed a large potential short-term and sustained decrease in CH₄ but would lead to continued CO₂ emissions from 3NOP production and use. Another important possible trade-off is that some mitigations resulted in lower total GHG emissions per farm but lower milk production per hectare. Under such circumstances, it is important to carefully consider unintended emissions that may arise as a result of management decisions to compensate for lower milk production per farm, such as land use change to increase the dairy area.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145058142","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}