Journal of Dairy Science最新文献

Red deer milk is known for its high nutritional quality, containing elevated levels of protein, fat, and essential minerals compared with other ruminant milks. This study investigates the protein profile of red deer milk across various lactation stages, using advanced liquid chromatography-MS/MS techniques to enhance understanding of its nutritional composition. In this study, milk samples were collected from 120 lactating does at 8 distinct points during the lactation period, ensuring consistent dietary conditions. Through this comprehensive approach, a total of 73 proteins were identified, with 9 previously known in deer milk. Significant variations in protein concentrations were observed, highlighting 27 proteins with substantial changes throughout lactation. These proteins are crucial for supporting the physiological needs of the fawn. Key findings revealed the roles of specific proteins, such as osteopontin and lactotransferrin, in immune function, alongside transport proteins involved in nutrient delivery, reflecting the dynamic requirements during lactation. Bioinformatics analysis indicated significant quantitative changes in protein expression, with regression analysis confirming these findings. Gene Ontology analysis was conducted; however, limitations in genomic data for red deer necessitated reliance on related species for functional annotation. The results underscore the complex biochemical changes in deer milk, establishing a foundational understanding of its unique proteome. In conclusion, despite identifying fewer proteins than observed in studies of other ruminants, this research represents the most thorough analysis of proteins in red deer milk to date. It emphasizes the dynamic nature of milk composition throughout lactation and its implications for nutritional and functional attributes in cosmetic products and food, thereby contributing valuable insights into the dairy potential of red deer.

As animal welfare concerns and pain management awareness in cattle increase, long-term analgesics can become a solution for the treatment of painful husbandry procedures. Cannabidiol (CBD) has anti-inflammatory and analgesic properties. Nevertheless, poor gastrointestinal absorption and first-pass liver metabolism results in low oral bioavailability in humans. The use of injected liposomal-CBD facilitates slow-drug-release, providing prolonged CBD plasma concentrations, with increased bioavailability. Study objectives were to determine preliminary pharmacokinetics and tolerability of a single subcutaneous injection of liposomal synthetic CBD (L-sCBD; 5 mg/kg) in 6 Holstein female neonatal calves. Blood was sampled for CBD and its metabolites, complete blood count, serum chemistry and serum amyloid A up to 6-wk. Vital signs and adverse effects were monitored. Data over time were compared with baseline using linear regression mixed effects. Plasma CBD concentrations were detected up to a median of 4.5 wk; with median peak plasma concentration (C_max) 44.1 ng/mL, median time to C_max 1 d and median half-life 5.3 d. The primary metabolite, 7-carboxy-CBD, exceeded CBD exposure by 9-fold (4-16) based on the area under the curve. A short-term significant neutrophil count increase was observed 2-d postinjection. Serum amyloid A decreased postinjection. The main adverse reaction was local swelling, which spontaneously resolved. Subcutaneous injection of L-sCBD produced detectable CBD plasma concentrations for several wk and was well-tolerated by calves. The use of injectable L-sCBD as an additional long-term analgesic in calves undergoing routine painful procedures (e.g., disbudding, castration) appears to have potential to decrease suffering and promote animal welfare, although further research is required to evaluate efficacy.

This study aimed to identify herd management styles and measures adopted by dairy farmers to extend cow lifespan and to explore the behavioral and farm-specific factors influencing these practices. A mixed-method approach was used, including a survey of 107 dairy farmers, in-depth interviews and farm visits with 10 farmers selected from the survey, of whom 5 had cows with a relatively low average lifespan (less than 4 years and 11 mo on average) and 5 had cows with a relatively high average lifespan (8 years or more on average). Surveyed farms were categorized into 3 lifespan classes (LC) based on the average age at culling: LC_low (<5.5 years, n = 28), LC_medium (5.5-6.5 years, n = 36), and LC_high (≥6.5 years, n = 34). Survey data included herd management styles, beliefs, values, and farm characteristics. Results showed limited differences in general (e.g., quality of drinking water, fertility, claw health) and specific (i.e., retain fewer female calves for replacement, inseminate cows more often before deciding to cull, treat sick cows for a longer period before deciding to cull) measures and in scores for behavioral factors across lifespan classes. However, LC_high farms were characterized by fewer cows, fewer youngstock, and lower annual milk yield per cow compared with LC_low farms. The LC_high farmers more frequently provided pasture access for at least 6 h per grazing day compared with LC_medium farmers. Farmers' attitudes and to a lesser extent descriptive social norms (referring to the pressure that farmers might feel by the actions of other people important to them) positively influenced their intention to adopt additional measures for extending cow lifespan. Qualitative interviews highlighted key themes farmers thought contributed to lifespan, including breeding, housing systems, grazing, and animal focus. The LC_high farmers emphasized they aimed for robust, muscular, and trouble-free cows, and a frequent presence in the barn, while LC_low farmers mentioned a broad range of focus areas. The results suggest that extending cow lifespan is influenced more by farmers' attitudes and (to a lesser extent) social norms than by specific farm practices or other behavioral constructs. Encouraging positive attitudes through tailored communication and peer learning activities and addressing barriers to adopting lifespan measures might be critical for broader implementation.

Modern dairy cattle populations have been intensively selected for high milk production; therefore, cows experience significant metabolic stress after calving and during the transition period. Breeding strategies aimed at making cows more robust and resistant to diseases without compromising milk productivity exist and have been implemented in some countries. Whereas genomic investigations have been conducted on both clinical and subclinical forms of ketosis, few studies have focused on measurable features reflecting metabolic processes, such as the blood concentrations of BHB and nonesterified fatty acids (NEFA) and urea, an indicator of nitrogen metabolism. A better understanding of the coding genes and polygenic nature of blood metabolites is advisable for genomic selection and evaluation. Therefore, this study aimed to identify genomic regions associated with major hematic biomarkers of ketosis predicted from mid-infrared milk spectra in the Italian Holstein population. A single-step GWAS was performed using predicted blood phenotypes collected from 6,190 clinically healthy Holstein cows from 5 to 35 DIM, reared in 374 herds, and genotyped with arrays of different SNP density. The analyzed traits included: BHB (log-transformed), NEFA (log-transformed), urea concentration (mmol/L), and subclinical ketosis (SCK), which was identified when BHB was ≥1.20 mmol/L. Specifically, 5.51% of cows were identified as being at risk of SCK. After imputation and conventional quality control, 64,202 markers located in the autosomes were used for the association study. The genomic h² was generally low (<0.11) for all the traits investigated. Signals of BHB were scattered across several locations (BTA2, 4, 6, 7, 18, 21, 22, 25, and 28) in regions related to metabolic processes and immune system function and response. In contrast, the significant SNP for SCK were mainly concentrated in BTA1, 5, 11, and 15, confirming the combined action of multiple genes on health-related phenotypes and suggesting that the genetic control of SCK is more restricted to specific chromosomal regions than that of blood biomarker concentration. For traits such as NEFA and urea, the number of significant signals was lower, and they were mainly related to lipid metabolism. Although the results should be interpreted with caution and validated in future research, our findings provide novel insights into the genetic and molecular mechanisms underlying negative energy balance and SCK in Holstein cows, offering potential targets for future functional studies and genetic improvement strategies.

Highly pathogenic avian influenza (HPAI) A(H5N1) virus emerged in lactating dairy cattle in March 2024, causing mastitis-related disease and infections in other farm animals and workers. Recent work identified α2,6 and α2,3-linked sialic acids (SIA), which serve as influenza virus receptors, in the lactating bovine mammary gland; however, their distribution across stages of mammary growth and development remains unknown. We compared the distribution of sialylation in mammary glands of prepubertal dairy calves, primigravid dairy heifers, and lactating cows. Mammary glands at all physiological stages displayed both α2,6 SIA, the preferred receptor linkage for human influenza viruses, and α2,3 SIA, the preferred receptor linkage for avian influenza viruses. Importantly, in mammary glands of pregnant dairy heifers, α2,3 SIA was most abundant, distributed in both mammary tissue and alveolar lumens. Our results indicate that the mammary glands of pregnant dairy heifers, like those of lactating dairy cows, display receptors that could support H5N1 binding and entry. Further studies are needed to determine whether developing mammary glands can be a site of influenza virus replication.

This study evaluated how the form and fatty acid (FA) profile of dietary fat supplements influence nutrient digestibility and milk yield in mid-lactation dairy cows. Twenty multiparous Holstein cows (mean ± SD; 44.3 ± 3.00 kg/d of milk; 99 ± 23 DIM) were randomly assigned to treatment sequences in a replicated 4 × 4 Latin square design with 21-d periods. Treatments were a non-FA-supplemented control diet (CON) and 3 diets incorporating FA supplements at 2.0% DM of total FA of 1) blend of FA supplements to achieve a ratio of 70% palmitic (C16:0) + 20% oleic (cis-9 C18:1) using an FA prill and a Ca-salt of palm FA (PFAD) distillate (70FB), 2) a Ca-salt of fractionated FA containing 70% C16:0 + 20% cis-9 C18:1 (70CS), and 3) a Ca-salt of PFAD distillate containing 45% C16:0 + 35% cis-9 C18:1 (45CS). The 3 FA treatments replaced soyhulls in the CON diet. The statistical model included the random effect of cow within square and the fixed effects of treatment, period, and square. Preplanned contrasts included CON versus the average of the 3 FA treatments (FAS), the form of the FA supplement (70FB vs. 70CS), and the FA profile of the Ca-salt (70CS vs. 45CS). Compared with CON, FAS decreased DMI and NDF intake, increased intakes of 16-carbon, 18-carbon, and total FA, and increased digestibility of DM, NDF, 16-carbon, 18-carbon, and total FA. There was no difference in nutrient intake for the form of the supplement, but compared with 70CS, 70FB increased DM and 18-carbon digestibility and decreased NDF and 16-carbon digestibility, with no effect on total FA digestibility. When considering the FA profile of a Ca-salt, 70CS increased both DM and NDF intake but did not affect the digestibility of DM or NDF and decreased 16-carbon and total FA digestibility. Overall, FAS increased 3.5% FCM and milk fat yield but decreased milk protein yield. No differences were observed for production responses when comparing the form of the supplement. When comparing the FA profile of a Ca-salt, 70CS increased milk fat yield but decreased yields of milk and milk lactose. In conclusion, FAS primarily increased milk fat production by increasing FA digestibility and absorption. Digestibility varied slightly by supplement form, but production variables remained consistent regardless of form when FA profiles were similar. However, differences in FA profiles between traditional Ca-salt containing 45% C16:0 and 35% cis-9 C18:1 and 70% C16:0 and 20% cis-9 C18:1 influenced nutrient digestibility and production. These findings demonstrate that FA profile had a greater influence than supplement on nutrient digestion and production outcomes.

This paper explores stakeholder responses to policy changes under Ireland's Fifth Nitrates Action Programme (NAP), focusing on the effectiveness of a top-down, compliance-driven approach. Despite the Water Framework and the Nitrates Directives, overall biological status in Irish waterbodies has shown little improvement. Using semi-structured interviews with 16 key informants and responses to open-ended questions from surveys with 42 dairy farmers, responses to qualitative questions, the study analyzes perceptions of new measures and the broader social and ecological challenges influencing water quality outcomes. Although regulation is viewed as necessary to encourage change at the farm level, participants highlighted that it overlooks the complexities of soil, water, and grassland interactions, and provides insufficient support for farmers. Findings underscore the limitations of regulatory compliance alone, pointing factors such as collective responsibility, local ownership, societal pressure, and ecological and hydrological complexity. The article concludes that a more integrated and context-sensitive approach is needed.

The study aimed to formulate fortified dry yogurt with chamomile and saffron, making a functional, probiotic, and therapeutic food. Fortified dry yogurt was prepared in 7:2:1 ratios of dry yogurt, chamomile, and saffron powders. Flavoring of fortified dry yogurt was done at 7:3 ratios of fortified dry yogurt and each flavor (mint, cumin seeds, fennel seeds, and black pepper powder). The prepared fortified dry yogurt was acidic (pH 3-4) and the total soluble solids were 49.97% of the product concentrate. Plain yogurt (100% natural plain yogurt) had the highest sensory scores regarding appearance, texture, color, taste, aroma, flavor, consistency, mouthfeel, and overall acceptability, whereas fortified dry yogurt (FDY) had the lowest scores. Among 4 flavors of FDY, the cumin-flavored fortified dry yogurt (CFFDY) showed the highest organoleptic potential and was selected for further analysis. The CFFDY proximate profile contains a low fiber concentration but is rich in moisture (7.55%), ash (8.13%), protein (9.22%), fat (21.85%), and CHO (52.360%), and 442.73 Kcal/100 g. The mineral profile of CFFDY contains low magnesium, but calcium (397.71 mg/100 g) and sodium (776.89 mg/100 g) were high. The total phenolic content (582.78 mg of GAE/100 g), flavonoid content (204.92 mg of QE/100 g), and ferric reducing antioxidant power (2,022.82 mg Eq. of FeSO₄/100 g) show the stronger antioxidant potential of CFFDY. Pathogenic bacterial species was not detected in CFFDY, but the total plate count was 2.5 × 10³ cfu/g, indicating the presence of probiotic species. Gram staining detected small chains of gram-positive cocci cells and medium chains of gram-positive palisades that are Bacillus and Bifidobacterium species, whereas glucose fermentation and lactose fermentation tests both confirmed the presence of Lactobacillus in CFFDY. A storage study of FDY was also conducted and revealed high potential organoleptic properties at d 90. Therefore, a novel formulation of flavored FDY may be adopted in the dairy industry, serving as a functional alternative and shelf-stable dairy product.

Contamination by Cronobacter sakazakii in powdered infant formula (PIF) and the potential hazards of chemical disinfectants are pressing issues requiring urgent resolution. This study aimed to investigate the antibacterial activity and mechanism of Lonicera japonica Thunb. polyphenols (LP) against C. sakazakii and evaluate the efficacy of LP as a natural disinfectant in inhibiting C. sakazakii in biofilms on the common contact surfaces of PIF. The results showed that the minimum inhibitory concentration and minimum bactericidal concentration of LP against C. sakazakii were 4 to 8 mg/mL and 8 to 16 mg/mL, respectively. Compared with controls, LP-treated C. sakazakii showed significantly reduced intracellular ATP and reactive oxygen species levels (P < 0.05); increases in AKP, protein, and nucleic acid leakage (P < 0.05); obvious cell membrane depolarization; enhanced membrane permeability; and irreversible cell morphological damage. Untargeted metabolomics analysis identified a total of 536 differential metabolites. Among them, 67 key differential metabolites were involved in fatty acid metabolism, amino acid metabolism, energy metabolism, membrane transport metabolism, and nucleotide metabolism, thereby disrupting the structure and function of the cell wall and cell membrane, reducing the resistance to environmental stress, and inhibiting ATP and nucleic acid synthesis. Application tests demonstrated that LP can significantly inactivate C. sakazakii in biofilms on stainless steel, glass, tinplate, and polyvinyl chloride surfaces. These findings deeply reveal the antibacterial mechanism of LP against C. sakazakii, and provide a theoretical basis for the application of LP as a natural disinfectant to reduce C. sakazakii contamination of PIF.