Journal of Dairy Science最新文献

{"title":"Association of fertility traits with markers of oocyte competence in dairy cattle.","authors":"B Chasi, J P Andrade, P L J Monteiro, B Castro, E Moreno, E Anta, N N Ali, J B Cole, M C Wiltbank, F Peñagaricano, A Z Balboula, M S Ortega","doi":"10.3168/jds.2025-26726","DOIUrl":"https://doi.org/10.3168/jds.2025-26726","url":null,"abstract":"<p><p>Fertility traits such as daughter pregnancy rate (DPR), cow conception rate, and heifer conception rate are key predictors of reproductive performance in dairy herds. However, their low heritability, likely due to their multifactorial nature and difficulty in measuring phenotypes, poses challenges for genetic improvement. Oocyte competence, encompassing nuclear and cytoplasmic maturation, is a critical factor influencing fertility. Errors in chromosome segregation during nuclear maturation can result in aneuploidy, which leads to embryonic mortality. During cytoplasmic maturation, mitochondrial replication is vital for energy production to support subsequent embryo development. The objective of this work was to investigate the association between fertility traits and markers of oocyte competence after in vitro maturation in dairy cattle. To do this, 105 Holstein cows with 32 to 52 d of pregnancy and ranging from 1 to 6 lactations were enrolled in the study. Cumulus oocyte complexes (COC) were collected by ovum pickup (OPU). Each cow was subjected to OPU 3 times, and collected COC were classified by grade following International Embryo Transfer Society guidelines. For maturation, COC were split into groups by grade as either grade 1 and 2 or grade 3 and 4. After maturation, COC were used for 2 analyses: aneuploidy screening and mitochondrial copy number. Low-fertility cows, based on DPR, might harbor genetic variants associated with elevated oocyte aneuploidy rates, potentially contributing to their reduced fertility. No association was found between mitochondria copy number and fertility traits. Further research needs to be performed on mitochondria functionality and its relationship with fertility. In conclusion, high-fertility cows based on DPR had fewer oocytes with chromosomal abnormalities, which could explain improved fertility.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005789","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":"Genome-wide association study and fine-mapping using imputed sequences to prioritize candidate genes for 30 complex traits in 50,309 Holstein bulls.","authors":"Junjian Wang, Yahui Gao, Sajjad Toghiani, John B Cole, Christian Maltecca, Li Ma, Jicai Jiang","doi":"10.3168/jds.2025-27058","DOIUrl":"https://doi.org/10.3168/jds.2025-27058","url":null,"abstract":"<p><p>Identifying causal genetic variants underlying economically important traits in dairy cattle is essential for understanding their genetic basis and optimizing breeding programs. The growing availability of sequenced reference genomes and individuals with both phenotypic and genotypic data notably enhances our ability to detect genetic associations and further pinpoint causal effects. This comprehensive GWAS of dairy cattle used deregressed breeding values as phenotypes and analyzed 11,292,243 quality-controlled, imputed sequence variants from 50,309 Holstein bulls. The number of bulls with available phenotypes ranged from 23,121 to 50,309 across 30 complex traits categorized into production and yield, type, and longevity and health. We performed GWAS using our SLEMM-GWA approach, which accounts for the varying reliability of deregressed breeding values across individuals and demonstrates computational efficiency for large sample sizes and sequence data. This analysis identified 381 significant association peaks, of which 126 are novel findings. Subsequent Bayesian fine-mapping provided statistical prioritization by assigning posterior conditional inclusion probabilities to individual variants and genes, yielding a list of credible candidate genes-an advancement over conventional GWAS reporting of all proximal genes. This prioritization offered direct statistical support for previously reported genes and, more importantly, identified credible candidate genes within the 126 newly discovered peaks for specific traits, including AOPEP, GC, E2F6, MGST1, VPS13B, ZNF652, ASPH, SFMBT1, and MAPRE2. These findings enhance the understanding of the genetic architecture of these complex dairy traits and provide valuable insights for the refinement of genomic selection strategies and breeding programs in Holstein cattle.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Invited review: Structural-functional synergies of lactoferrin-bioactive compound complexes: Multidisciplinary applications.","authors":"Jiaqi Chen, Tiehua Zhang, Tolulope Joshua Ashaolu, Changhui Zhao","doi":"10.3168/jds.2025-26630","DOIUrl":"https://doi.org/10.3168/jds.2025-26630","url":null,"abstract":"<p><p>This review article presents an overview of the structure-function characteristics and extensive applications of complexes formed between lactoferrin (Lf) and various bioactive compounds. Lactoferrin, a glycoprotein predominantly found in colostrum, possesses iron-binding capacity and exhibits a wide range of biological activities, including antibacterial, antiviral, antifungal, antiparasitic, anti-inflammatory, anticancer, and antitumor effects. Through complexation with proteins, phenolic compounds, polysaccharides, and other bioactive substances, the structural and functional properties of Lf are significantly improved, enhancing its potential applications in the food, pharmaceutical, cosmetic, and industrial sectors. This article first introduces the basic properties, structure, and biological functions of Lf. Subsequently, it elaborates on the factors influencing the complexation reaction of Lf and the structure-function changes after its complexation with different bioactive compounds. Finally, it summarizes the applications of Lf-bioactive compound complexes in dairy products, virus inhibition, cosmetics, medicine, and agriculture, and forecasts their future development directions.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005752","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":"Carryover effects of feeding tropical fresh or air-dried roughage to Holstein-Friesian crossbred dairy cows on nutritional, techno-functional, and sensory properties of mozzarella cheese.","authors":"A Rahman, M A H Sarker, M H Rashid, M S Bari, S Arefin, R Jahan, M A Kabir, E Rukke, P Salunke, M E Uddin, M A Islam","doi":"10.3168/jds.2025-26819","DOIUrl":"https://doi.org/10.3168/jds.2025-26819","url":null,"abstract":"<p><p>This study investigated how different dietary roughages, Napier-Pakchong (NP), jumbo sorghum (JB), and rice straw (RS) fed to Holstein-Friesian (HF) crossbred cows affect the nutritional, techno-functional, and sensory properties of mozzarella cheese under tropical conditions in Bangladesh. Iso-nitrogenous (≈12.54% CP) and iso-energetic (ME ≈2.35 Mcal/kg of DM) diets were fed to cows in a 33-d long trial, and mozzarella cheese was produced from milk collected over the last 3 d. One-way ANOVA was performed using SAS (version 9.1) to assess the effects of roughage sources on different attributes of the mozzarella cheese. The JB and RS groups had greater moisture-corrected cheese yield and fat content than the NP group. However, cheese from NP and RS had a greater protein content (20.7% vs. 17.7%) and lightness index (L* 95-97 vs. 90) than the JB. Cheese from RS group had greater hardness, gumminess, and chewiness, JB cheese had greater melting, and the NP group had greater stretching properties. In sensory analysis, the NP group cheese had a better mouth feel and was juicier but had reduced elasticity. Although saturated fatty acids did not differ, NP cheese contained more unsaturated fatty acids (C18:1 trans-9; C18:3 cis-9,12,15) and a lower thrombogenicity index. In conclusion, roughage sources altered the nutritional profile, color, textural, functional, and sensorial characteristics of mozzarella cheese.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005772","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":"Noninvasive multiclass milk contaminants detection using hyperspectral imaging and hybrid ensemble learning.","authors":"Muhammad Iqbal, Muhammad Aqeel, Ahmed Sohaib","doi":"10.3168/jds.2025-27141","DOIUrl":"https://doi.org/10.3168/jds.2025-27141","url":null,"abstract":"<p><p>Food contamination remains a serious global concern due to its health risks, with milk being one of the most commonly adulterated foods in developing countries such as Pakistan, India, and Bangladesh. Accurate detection of milk contamination is essential for ensuring consumer safety and maintaining food industry standards. This study explores both invasive and noninvasive approaches for contamination analysis. The invasive method uses the Lactoscan system to assess parameters such as fat, conductivity, protein, density, solids, lactose, temperature, pH, and SNF across varying contamination levels. The noninvasive method employs hyperspectral imaging using the Specim FX-10 system (400-1,000 nm) to detect contamination through spectral and spatial analysis. Preprocessing involved image resizing and region of interest selection for feature extraction, as well as radiometric correction using the empirical line method. Postprocessing included noise reduction and spectral smoothing using the Savitzky-Golay filter. The resulting clean spectral data were classified using a hybrid ensemble learning (HEL) framework, which combines voting and stacking ensembles of gradient boosting, XGBoost, LightGBM, and multilayer perceptron models. Comparative results show the HEL approach significantly outperforms existing methods, achieving 100% training and 96% validation accuracy-demonstrating its potential for real-time, noninvasive milk quality assurance.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005720","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":"Are there too many traits in our selection indices?","authors":"John B Cole","doi":"10.3168/jds.2024-25833","DOIUrl":"https://doi.org/10.3168/jds.2024-25833","url":null,"abstract":"<p><p>Selective breeding has been practiced since domestication, but early breeders commonly selected on appearance (e.g., coat color) rather than performance traits (e.g., milk yield). A breeding index converts information about several traits into a single number, typically representing total economic merit, that can be used for selection or to predict an animal's own performance. The first USDA selection index released in 1971 included only milk and fat yield, whereas the 2025 revision of the Lifetime Net Merit (NM$) index includes 17 traits and composites (weighted averages of other traits). Many dairy farmers, semen salespeople, sire analysts, and genetics consultants (expressed in personal communications) are concerned that, as the number of traits in the index grows, it becomes less effective because selection response is \"diluted\" (the efficiency of the index decreases). What actually happens is that the response in individual traits changes, but the overall index response (total economic merit) does not. Correlated response to selection for 24 traits and composites currently evaluated by the Council on Dairy Cattle Breeding (Bowie, MD) and Holstein Association USA (Brattleboro, VT) was calculated for 12 USDA selection indices and their changes over time were examined. Indices including only yield (milk, fat, and protein) traits had the highest heritabilities (0.272-0.290), whereas NM$ had heritabilities ranging from 0.188 in 2010 to 0.243 in 2025. Rates of genetic gain have changed over time but are in favorable directions for most traits. Although selection response has slowed for some traits (e.g., production) as new traits were added to the index, they remain favorable (positive). Other traits, most notably fertility, now have favorable trends when they had unfavorable (negative) trends in earlier versions of the selection index. There is some reranking within birth year cohorts for both genetic merit and reliabilities because older animals were selected using different criteria than contemporary animals. Rank correlations are high across indices, ranging from 0.8746 to 0.9994, meaning that sires rank similarly despite the increasing complexity of the index. Selection gains for fat, protein, productive life, and BW composite have the greatest economic value regardless of how responses are calculated. These results show that properly constructed selection indices produce desirable rates and directions of gain for many traits at once.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005722","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":"Astragalus polysaccharides restore neutrophil functions and gut microbiota homeostasis in dairy cows with subclinical ketosis.","authors":"Shang Jiang, Li Na, Ke Zhang, Kexin Wang, Zhiyong Li, Yiqi Zhang, Yan Ren, Chao Wang, Xiancheng Feng, Yuchen Yang, Chenxi Xue, Jun Chen, Xiliang Du, Lin Lei, Wenwen Gao, Guowen Liu, Yuxiang Song, Xinwei Li","doi":"10.3168/jds.2025-26901","DOIUrl":"https://doi.org/10.3168/jds.2025-26901","url":null,"abstract":"<p><p>Subclinical ketosis (SCK) in periparturient cows is associated with gut microbiota dysbiosis and energy metabolism disorders. Although in vitro studies show that free fatty acids (FFA) and BHB impair polymorphonuclear neutrophil (PMN) functions-potentially causing secondary infections-limited in vivo evidence exists. Astragalus polysaccharides (APS) modulate metabolism, immunity, and gut microbiota, but their effects on PMN functions and gut microbiota in SCK cows remain unclear. This study aims to evaluate PMN dysfunction and gut microbiota dysbiosis in SCK cows, and clarify the protective effects of APS on these parameters. Multiparous cows were classified into control (CON; n = 40) and SCK (n = 38) groups based on serum BHB levels. Compared with CON cows, SCK cows exhibited reduced feed intake, negative energy balance (NEB), and dysfunctional PMN activation-characterized by inhibited phagocytosis/neutrophil extracellular traps (NET) and enhanced respiratory burst/degranulation. Supplementation with APS restored PMN functional balance (increasing phagocytosis and reducing respiratory burst/degranulation) and alleviated NEB. Subclinical ketosis decreased gut microbiota α- and β-diversity without altering dominant phyla. At the genus level, SCK reduced Monoglobus, Faecalibacterium, Ruminococcus (short-chain fatty acid [SCFA]-producers), and increased Prevotella and Parabacteroides. Astragalus polysaccharides reversed these changes. Serum FFA and BHB negatively correlated with Monoglobus and Ruminococcus, whose decline likely contributed to NEB. Polymorphonuclear neutrophil reactive oxygen species and serum myeloperoxidase levels negatively correlated with Faecalibacterium, Ruminococcus, and Monoglobus. The predicted microbial community function also showed a decrease in the levels of propanoate and butanoate metabolism in SCK cows, suggesting that deficiency of SCFA-producing microbiota likely promoted PMN hyperactivation in SCK. Our study identifies a microbiota-energy metabolism-immunity pathway disrupted by SCK in periparturient cows. Astragalus polysaccharide supplementation restores this pathway by normalizing gut microbiota, alleviating NEB, and correcting PMN dysfunction. This work provides mechanistic insights into metabolic-immune disorders and validates APS as a natural intervention to improve dairy cow health during the critical transition period.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005733","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 a commercial buckwheat rhizome flavonoid extract on milk production, plasma pro-oxidant and antioxidant, and the ruminal metagenome and metabolites in lactating dairy goats.","authors":"Q Lu, J X Qin, S L Xie, R Chen, Y Q Xu, Y M Ban, C C Gao, P Y Li, X Wang, X Z Tian","doi":"10.3168/jds.2024-26208","DOIUrl":"https://doi.org/10.3168/jds.2024-26208","url":null,"abstract":"<p><p>Buckwheat is a common straw crop that contains an abundance of flavonoids and could be used as an antioxidant additive in animal diets. In this study, the effects of a commercial buckwheat rhizome flavonoid extract (BRFE) on milk production, plasma pro-oxidant and antioxidant, the ruminal metagenome, and ruminal metabolites in dairy goats were evaluated. Forty healthy, multiparous, nonpregnant Guanzhong dairy goats were blocked by DIM (122 ± 5.1 d), milk yield (1,461 ± 91 g/d), parity (3.80 ± 0.76 lactations), and BW (44.18 ± 2.47 kg), and were assigned to 1 of 4 diets. The control (CON) goats were fed the basal total mixed ratio, whereas the goats in treatment groups 1, 2, and 3 were fed the CON diet supplemented with 70, 140 (MB), and 210 mg/kg of a commercial BRFE (Shaanxi Haiyisi Biotechnology Co. Ltd., Xian, China) on a DM basis of the diet, respectively. The goats were fed these diets for a total of 63 d, with a 21-d adaptation period and a 42-d experimental period. Individual DMI and milk yield were recorded daily. Milk component samples were collected on d 6, 7, 13, 14, 20, 21, 27, 28, 34, 35, 41, and 42 of the experimental period; blood and ruminal fluid samples were collected on d 1, 21, and 42 of the experimental period. The results indicated that all milk production variables (milk yield, 3.5% FCM, fat, protein, lactose, and SNF yields) linearly and quadratically increased with increasing BRFE supplementation, and these variables were the highest in the MB group. The plasma total antioxidant capacity and superoxide dismutase increased linearly and quadratically with increasing BRFE supplementation. The plasma malondialdehyde and superoxide anion contents linearly and quadratically decreased with increasing dietary BRFE content. The ruminal fluid propionate content linearly and quadratically increased with BRFE supplementation. The ruminal acetate:propionate ratio linearly and quadratically decreased with increasing BRFE content. Compared with CON, feeding 140 mg/kg BRFE reduced the ruminal fluid abundances of Synergistetes at the phylum level and Quinella at the genus level. Dietary supplementation with BRFE increased the abundance of carbohydrate-digesting enzymes in ruminal fluid, among which glycoside hydrolase family 2 was the most dominant. Metabolomic analysis indicated that supplementation with BRFE enriched tryptophan metabolism in the rumen. Overall, this study revealed that dietary supplementation with BRFE increased plasma antioxidant capabilities and milk production and improved ruminal fermentation, the ruminal metagenome, and ruminal tryptophan metabolism in lactating dairy goats.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005792","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":"Prepartum nutrient intake alters glucogenic capacity of liver slices from peripartal dairy cows.","authors":"N B Litherland, H M Dann, J K Drackley","doi":"10.3168/jds.2025-26613","DOIUrl":"https://doi.org/10.3168/jds.2025-26613","url":null,"abstract":"<p><p>Ruminants rely on hepatic gluconeogenesis to support whole-body glucose metabolism and to supply glucose for lactose synthesis. Understanding the effect of plane of nutrition before parturition on the capacity for hepatic gluconeogenesis in dairy cows may provide a basis for improved cow health and productivity in the subsequent lactation. Our objectives were to determine the effects of far-off (FO) dry period diet, close-up (CU) period diet, and their interaction on adaptations in metabolism of gluconeogenic substrates (Ala and propionate) in liver slices. Multiparous Holstein cows (n = 71) were fed different amounts of nutrients during the FO and CU dry periods in a 3 (FO diet) × 2 (CU diet) factorial arrangement. During the FO period (d -60 to -25 before calving) cows received a control diet fed for ad libitum intake to meet NRC recommendations (100NRC), a moderate energy diet fed ad libitum to exceed NRC recommendation for NEL by at least 50% (150NRC), or the moderate energy diet fed at restricted intake to meet 80% of NEL requirements (80NRC). During the CU period (d -24 until parturition), cows were fed a diet either for ad libitum intake (CUA) to meet or exceed NRC recommendations or in restricted (CUR) amounts to provide 80% of calculated NEL requirements. All cows received the same lactation diet postpartum. Liver slices from biopsies at d -30, -14, 1, 14, and 28 relative to parturition were used to determine in vitro conversion of [1-¹⁴C] Ala and [1-¹⁴C] propionate to glucose and CO₂. Gluconeogenic rates from propionate were 71%, 37%, and 73% greater than from Ala on d 1 for cows fed 100NRC, 150NRC, and 80NRC, respectively. Gluconeogenesis from propionate was significantly greater on d -14 and d 28 for cows fed 80NRC compared with 100NRC and 150NRC. Oxidation of propionate to CO₂ increased from d -14 to d 1 postpartum for all far-off treatments. On d -14, oxidation of propionate to CO₂ tended to be lower for 100NRC versus 150NRC and 80NRC. Gluconeogenesis from Ala on d -30 tended to be less for 150NRC compared with 80NRC. Gluconeogenesis from Ala tended to be greater for CUR on d 14. Oxidation of Ala to CO₂ was not significantly different among treatments tended to be higher on d 1 postpartum for 100NRC. Close-up diets had minimal effects on gluconeogenesis and substrate oxidation. Cows fed restricted amounts of energy in the FO dry period had greater hepatic gluconeogenic capacity both prepartum and postpartum compared with those fed excess amounts of energy relative to requirements. Controlling energy intake during the far-off dry period can alter hepatic capacity for gluconeogenesis from propionate and Ala, which may confer an advantage to the cow by adapting metabolic processes before parturition and resulting in improved health and productivity.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005731","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":"Effect of delactosed whey permeate on lactation performance and total-tract nutrient digestibility on high-producing dairy cows.","authors":"Karissa A Juckem, E Cole Diepersloot, Matheus R Pupo, Luiz F Ferraretto","doi":"10.3168/jds.2025-27000","DOIUrl":"https://doi.org/10.3168/jds.2025-27000","url":null,"abstract":"<p><p>The objective of this study was to evaluate the effects of forage fiber and starch sources replacement with delactosed whey permeate (DLP) on lactation performance and total-tract nutrient digestibility of high-producing dairy cows. Ninety-six multiparous Holstein cows (88 ± 36 DIM) and dietary treatments were randomly assigned to 12 pens of 8 cows for an 8-wk treatment period, after a 2-wk covariate period. Treatments were diets fed without DLP (CON), 5% replacement of corn silage with DLP (LCS), and 5% replacement of high-moisture corn with DLP (LHMC). Data were analyzed as a completely randomized design with data from the 2-wk covariate period used as a covariate using a mixed model with week of treatment as repeated measures. The model included treatment, week, and their interaction as fixed effects, and treatment within pen as a random effect. The CON diet tended to have 1.4 kg/d greater DMI than LCS but did not differ from LHMC. The CON diet had a greater milk yield compared with LCS by 2.2 kg/d and LHMC by 2.7 kg/d. Similarly, cows fed CON had 0.04 percentage units and 0.07 percentage units greater milk lactose concentration compared with LHMC and LCS, respectively. Milk fat yield tended to be greater for CON than LCS, but concentration did not differ between treatments. Diets with partial replacement with DLP had 0.05 percentage units greater milk protein concentration. However, no effects on feed efficiency were observed with replacement with DLP. Digestibility of DM, OM, and CP were greater for LCS diet compared with LHMC by 3.4 percentage units, 3 percentage units, and 3.8 percentage units, respectively. Ether extract digestibility tended to be 4.1 percentage units greater for LCS than LHMC. Additionally, NDF digestibility of the LCS diet was greater than CON and LHMC by 6.1%, on average. These findings suggest that replacing high-moisture corn or corn silage with DLP may decrease milk yield and milk lactose concentration but increase milk protein concentration. However, DLP can have positive effects on total-tract digestibility when replacing corn silage but not when replacing high-moisture corn.</p>","PeriodicalId":354,"journal":{"name":"Journal of Dairy Science","volume":" ","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005759","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}