Journal of Dairy Science最新文献

Fermented dairy products are increasingly valued not only for their nutritional content but also for their potential health-promoting properties. However, assessing these functional benefits often requires time-consuming chemical assays that limit scalability. In this study, we investigated whether deep learning (DL) could offer a faster, more efficient alternative. Using liquid chromatography (LC)-MS quadrupole time-of-flight metabolomics, we analyzed 18 fermented milk samples (derived from camel and bovine milk fermented with different bacterial strains) and measured their bioactivity across 9 in vitro assays, including antioxidant capacity (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), 2,2-diphenyl-1-picrylhydrazyl), enzyme inhibition (angiotensin-converting enzyme, DH), and anticancer activity (HT-29, MDAMB). To address the challenge of limited sample size, we implemented a robust preprocessing pipeline including outlier detection, robust scaling, and data augmentation techniques. We trained a one-dimensional convolutional neural network (1D-CNN; DL) architecture with regularization strategies to predict these bioactivity scores from preprocessed LC-MS data. The model achieved strong performance with a mean absolute error of 0.548 ± 0.089 across all outputs through 3-fold cross-validation, demonstrating effective generalization despite the small dataset. Principal component analysis revealed biologically meaningful structure in the metabolomic data, distinguishing samples by milk type and fermentation condition. Together, these results demonstrate that DL with appropriate regularization and data augmentation can accurately predict the functional bioactivity of fermented milk products from metabolomic signatures, offering a promising path toward scalable, DL-assisted screening in functional food development, even with limited training data.

Transportation is a significant stressor for cattle, but research is lacking regarding preweaning dairy calf transport practices in the United States. Improving our understanding of calf transportation practices can inform management practices that minimize welfare challenges of transport. The objectives of this study were to (1) describe current industry practices regarding transportation of preweaning dairy and beef-on-dairy crossbred calves, (2) determine differences in pre-transport management on dairies between replacement heifers, beef-on-dairy crossbreds, and dairy bull calves, and (3) identify outreach and research needs to address calf welfare concerns related to transportation. Dairy producers, calf raisers, or other individuals receiving transported calves, and haulers were recruited through digital advertisement, email, and extension agents to complete an online survey in 2023. Survey topics for dairy producers included pre-transport practices (e.g., colostrum management, health evaluations, marketing), and topics for operations that received transported calves included calf condition at arrival, preweaning disease incidence, and preconditioning requirements. Haulers were asked questions related to their route demographics (e.g., travel distance, number of stops, destination). Wilcoxon signed rank, Kruskal-Wallis, or McNemar tests were conducted to determine differences in calf management practices; the predictor of interest was calf class (replacement heifer, beef-on-dairy, dairy bull), and outcomes of interest included age at transport, colostrum timing and quantity, feeding and preconditioning practices before transport, calf health characteristics pre- and post-transport, and transport distance and duration. A total of 123 responses were accepted for analysis (n = 69 dairy producers; 29 operations that received transported calves; 25 haulers). Replacement heifers were transported at older ages, compared with beef-on-dairy calves, but no difference in age was found between replacement heifers and bulls or beef-on-dairy and bulls. More dairy operations reported vaccinating replacement heifers versus nonreplacement calves. Operations that received transported calves reported considerable variability in preweaning morbidity and mortality rates. Stakeholder groups also highlighted the need for best practice recommendations related to transport and increased communication and collaboration between dairies and calf raisers. Although this study was limited by a small sample size, our findings provide a deeper understanding of transport practices in the United States, which can be used to inform research and outreach efforts to promote the health and welfare of dairy calves and support the longevity of the dairy industry.

Although Lys has been widely used in dairy cows, its effects on lactational performance are inconsistent, and the potential interfering factors have not been systematically investigated. Thirty-three reviewed publications from PubMed, Web of Science, and Google Scholar databases up to March 31, 2025, were pooled to calculate the weighted mean differences (WMD) and CI for continuous variables using a stratified 3-level meta-analysis with a random-effects model. A moderator analysis was used to evaluate the influences of cow breed, lactational stage, dietary MP supply, basal diet type, and other additions, as well as methods, dosage, and duration of administration, on the effects of supplemental Lys. Results showed that Lys supplementation increased the milk yield (WMD = 0.52 kg/d, [0.30, 0.74]), milk protein yield (WMD = 0.03 kg/d, [0.02, 0.04]), milk protein concentration (WMD = 0.05%, [0.03, 0.07]), and milk fat yield (WMD = 0.02 kg/d, [0.01, 0.03]) in dairy cows. The positive effects of Lys supplementation on milk yield and milk fat yield were more prominent in dairy cows of Holstein breed, in cows fed an MP-adequate diet, in cows fed a corn silage-based diet, or in administration through feeding rumen-protected Lys compared with the respective other groups. The response of milk protein yield in dairy cows was greater when Lys was supplemented in early lactation (WMD = 0.04 kg/d, [0.02, 0.06]). Lysine supplementation along with Met significantly increased the milk yield (WMD = 1.09 kg/d, [0.53, 1.64]), whereas sole Lys addition had greater effects on milk protein concentration (WMD = 0.06%, [0.03, 0.09]). Regression analysis showed that the optimal dosage and duration of Lys supplementation for milk yield, milk protein yield, and milk fat yield were 203, 208, and 204 g/d (6.8%, 6.9%, and 6.8% of MP) and 90, 85, and 43 d, respectively. These findings collectively provide practical guidelines for Lys application in improving the lactational performance in dairy cows.

Constipation has emerged as an important public health concern, and novel therapeutic approaches, such as those, are attracting increasing attention. However, the effects and mechanisms of Bifidobacterium breve (B. breve) and Lacto-N-neotetraose (LNnT) in relieving constipation remain incompletely understood. Moreover, the potential synergistic effects of B. breve and LNnT in alleviating constipation are still unclear. In this study, we used 4-wk-old female BALB/c mice (n = 60), which were randomly assigned to normal control (NC) group, model control (MC) group, LNnT group, B. breve group, and B. breve+LNnT group. We evaluated the effects of B. breve+LNnT on defecation performance and intestinal mucus secretion. We also analyzed gut microbiota composition and metabolic functions. Additionally, an independent cohort of 45 mice was used to assess the effect of gut microbiota and microbiota-derived metabolites on constipation. The results demonstrated that B. breve+LNnT increased the gastrointestinal transit rate and fecal water content while reducing whole-gut transit time. It also elevated serum concentrations of gastrin (GAS) and motilin (MLT) while decreasing those of vasoactive intestinal peptide (VIP) and nitric oxide (NO). Mice receiving B. breve+LNnT showed increased intestinal mucus content, a more organized mucus layer structure, and higher expression of mucus-related genes (Muc2, Agr2, Muc1, Muc4, Muc13). Additionally, B. breve+LNnT increased gut microbiota diversity and enriched potentially beneficial microbiota, including Ruminococcus, Bifidobacterium, Tyzzerella, and Roseburia. Consistently, levels of the acetate and propionate were elevated in the B. breve+LNnT group. Correlation analysis indicated positive associations between these microbiota and acetate. Finally, we explored the role of gut microbiota, acetate, and propionate in constipation. We found that the alleviation of constipation by B. breve+LNnT depended on the presence of gut microbiota and was associated with microbiota-derived acetate.

Doum fruit, which contains valuable nutritional components and biologically active substances while being readily available, low-cost, and offering numerous health benefits, may present an innovative approach to yogurt fortification. The present study evaluated the physicochemical properties, microbiological counts, total phenolic content, total flavonoid content, antioxidant activity, antimicrobial activity, and sensory properties of set-type yogurt fortified with aqueous extract of doum fruit. The set-type yogurt samples were prepared with 5% and 10% aqueous extract of doum fruit and stored under refrigeration (4°C ± 1°C) for 21 d. The incorporation of aqueous extract of doum fruit improved the chemical composition of yogurt by increasing TS, protein, fat, ash, and dietary fiber contents compared with the control. The highest fiber content was recorded in the set-type yogurt fortified with 10% extract (0.92 ± 0.02 g/100 g) on d 21. Titratable acidity was lower in both fortified set-type yogurt samples compared with the control, with the 10% extract sample exhibiting the lowest value (0.88% ± 0.02%) on d 21. Antioxidant activity increased significantly in both fortified set-type yogurt samples, with the 10% extract sample showing the highest inhibition rate (49.80% ± 2.00%) on d 21. All set-type yogurt samples demonstrated antimicrobial activity, with the 10% extract sample producing the largest inhibition zones. Sensory evaluation showed that the yogurt fortified with 10% extract received the highest overall acceptance scores, particularly for taste, smell, and texture. These findings suggest that set-type yogurt enriched with aqueous extract of doum fruit represents a promising functional dairy product with enhanced antioxidant and antimicrobial activities while maintaining desirable sensory attributes. Further research is warranted to investigate the bioavailability and in vivo efficacy of its bioactive compounds.

Measurement of antimicrobial usage (AMU) on dairy farms is an important aspect of antimicrobial stewardship and has been performed using a variety of methods. The objectives of this observational study were to compare AMU estimated using data extracted from computerized herd records with estimates based on drug packaging inventories and to assess consistency in AMU during different periods. Data were collected between May 2023 and January 2024 from a convenience sample of 25 conventional dairy farms that recorded treatments in selected herd management software. During an initial farm visit, researchers used a custom online antimicrobial benchmarking program to retrospectively summarize AMU for mature cows over the previous 12 mo and provided containers to collect drug packaging waste. Researchers visited farms biweekly during a 4-mo period to collect and count discarded packaging and generated a second benchmark report at the end of the period. The software expressed AMU as defined daily dose (DDD) per cow per year, and the same metrics were calculated manually for health-related events that occurred during the prospective 4-mo period that drug packaging waste was collected. A t-test was used to evaluate differences between AMU estimated using the software for mo 1 and 4, and a 1-way ANOVA was used to assess differences in AMU among methods. Herds contained between 158 and 12,500 dairy cows, with bulk tank SCC ranging between 64,000 and 250,000 cells/mL and produced 38.6 (±1.56 SE) kg/cow per day of milk. Total AMU for the previous 12 mo estimated using software was 4.5 DDD/cow per year and did not differ between mo 1 and 4. Using the estimated AMU from the benchmarking software, no differences were identified for route or indication. No differences in AMU estimates were found based on method, and the interclass correlation coefficient varied from moderate to good agreement between methods. Within herds, a greater proportion of first-parity animals was associated with less AMU, whereas an increased proportion of third-parity animals was associated with greater injectable antibiotic usage. The estimates based on the benchmarking program, using 1-year retrospective data, demonstrated sufficient precision for understanding and managing AMU on dairy farms.