Journal of Dairy Research最新文献

As breeding has become increasingly specialized over the last decades, modern dairy breeds have mainly been focusing on milk production, producing bull and surplus female calves with low economic value. To address this dilemma, the present study evaluates how crossbreeding with the specialized beef breed Belgian Blue and pure breeding with Holstein-Friesian bulls affect calving ease and subsequent fattening performance, and carcass quality in Holstein-Friesian herds. For the study, pedigree information, calving information, as well as fattening performance and carcass quality parameters of 5,162 fattening bulls sired by either Holstein-Friesian (n = 4,607) or Belgian Blue (n = 555) sires from Holstein-Friesian cows in northern Germany were considered. Crossbred calves had higher birth weights and better carcass conformation ratings but also higher age at slaughter, carcass weight and average daily weight gain than purebred dairy calves, reflecting beef breeds' superior muscle development. However, crossbreeding with Belgian Blue sires also increased the frequency of difficult births (dystocia), which has previously been shown to negatively impact calf health. The effect of parity was not relevant for fattening and carcass quality parameters but highlighted the present breeding practice of using beef sires in multiparous rather than in primiparous cows. Seasonal variations were also observed, with spring and summer-born bulls exhibiting faster weight gain.

This research paper addresses the hypothesis that sequence-based long short-term memory (LSTM) architectures improve the prediction of the next DO (days open) relative to a feed-forward multi-layer perceptron and a Cox model under strictly temporally valid predictors. Modern dairy farming can heavily benefit from optimising 'days open' for profitability and animal welfare. Machine learning can forecast this metric, improving farm management, disease prevention and culling decisions. This study used a dataset of 16,472 breeding records. The study compared the performance of feed-forward neural networks and two types of recurrent neural networks (RNNs). The results showed that LSTM most accurately forecasted the next 'days open'. This demonstrates that RNN models, due to their ability to capture temporal patterns in the data, significantly outperform feed-forward and traditional statistical methods in terms of mean absolute error and concordance.

Mastitis, an inflammation of the mammary gland, is a disease of significant clinical and economic importance. In recent years, advances in omics technologies have provided powerful tools to unravel the complex biological mechanisms underlying mastitis. These approaches encompass diverse fields such as genomics, proteomics, transcriptomics, metagenomics, metabolomics, epigenomics, lipidomics, glycomics, pharmacogenomics, foodomics, interactomics and exposomics. However, despite the rapid growth of omics research, the thematic structure of this literature has not been systematically examined. In this study, latent dirichlet allocation (LDA) was employed to perform topic modelling on publications related to omics and mastitis retrieved from Scopus and Web of Science. The LDA analysis revealed ten distinct topics, labelled according to the most frequent terms within each cluster: 'proteomics', 'pathogen genomics', 'differential expression', 'metabolism', 'genetic selection', 'disease economy', 'molecular diagnostics', 'microbiome', 'antimicrobial resistance' and 'genetic variation.' Among these, the topics of 'genomics', 'differential expression' and 'antimicrobial resistance' accounted for the highest number of publications, while 'metabolism' emerged more recently. All topics exhibited an increasing trend in publication volume over time, likely driven by the declining costs and greater accessibility of high-throughput omics technologies. This study provides a comprehensive thematic overview of omics research on mastitis, identifies key areas of emphasis and emerging directions, and highlights knowledge gaps that may inform future investigations and the development of targeted strategies for disease control and prevention.

Metabolomics of faecal samples offers a non-invasive method to monitor gastrointestinal (GI) development and microbial activity in dairy heifers during key physiological transitions. In this longitudinal study, faecal metabolites from 10 Holstein heifers were analyzed from birth to first calving using targeted metabolomics. Faecal samples were collected at 12 h post-birth, week 6 (pre-weaning), week 14 (weaning), 8 months (post-weaning), and at first calving (26 ± 2.3 months). Calves were fed 3.8 L of colostrum within 2 h of birth, followed by 6 L of maternal transition milk for 5 days, then 6 L of milk replacer twice daily. Group housing began at 14 days. Partial least squares discriminant analysis (PLS-DA) showed distinct temporal clustering of faecal metabolites. Heatmap analysis revealed significant metabolite alterations, particularly between pre- and post-weaning stages. A linear mixed-effects model identified significant stage effects for all 17 amino acids. Of the 55 biogenic amines and amino acid-related metabolites, 48 significantly differed across stages. Elevated amino acids and polyamines early in life reflected colostrum intake and immature digestion, decreasing post-weaning, indicating improved nutrient absorption and rumen functionality. Increased microbiota-derived compounds, including β-alanine, serotonin, and indole derivatives, reflected microbial colonization and co-regulation with the host. Elevated dopamine, homocysteine, and phenylethylamine in late gestation indicated neuroactive and redox adaptations. Overall, faecal metabolite profiles provide insights into metabolic remodelling related to nutrition, GI maturation, and reproductive development, highlighting faecal metabolomics as a useful non-invasive tool for monitoring heifer development.

This Research Paper addresses the hypothesis that the use of a probiotic and the antioxidant and anti-inflammatory action of curcumin will improve the use of buttermilk, which is a by-product of the dairy industry that is still little used, despite its nutritional and technological properties. The production of beverages using buttermilk as a basis will contribute to the development of foods that support sustainability, reduce waste and have high nutritional quality. The aim of this research is to develop a functional dairy beverage with high antioxidant potential, combining probiotic (Lactobacillus gasseri LG08) and bioactive compounds through buttermilk fermentation and curcumin addition. To this end, four formulations were prepared: (1) pasteurized buttermilk (BM), (2) pasteurized buttermilk + curcumin (CUR), (3) pasteurized fermented (L. gasseri LG08) buttermilk (FBM) and (4) pasteurized fermented (L. gasseri LG08) buttermilk + curcumin (FCUR). We evaluated proximal composition and physicochemical properties (pH, titratable acidity, soluble solids, colour and water-holding capacity), microbiological and antioxidant capacity over 28 days and in vitro cytotoxicity. For comparison among experimental formulations, ANOVA followed by the Tukey test was used for parametric variables, and for non-parametric variables, Kruskal-Wallis followed by Dunn's, using BM as the control. For comparison over storage time, ANOVA was performed. The analyses show the effect of fermentation on beverages with added Lactobacillus, with a reduction in pH and an increase in acidity. The use of curcumin resulted in changes not only in colour but also in the antioxidant content of the beverages. At 100 μg/ml, all formulations were non-cytotoxic. Furthermore, in the evaluation of cell viability, the FCUR beverage at the highest concentration improved viability after stress with hydrogen peroxide. Fermentation using the lactose content in buttermilk was effective. Curcumin enhanced visual appeal and bioactivity without cytotoxic effects. Utilizing underused by-products reduces waste and supports sustainability.

Salmonella enterica serovar Dublin is host-specific to cattle, causing severe symptoms and economically impacting milk herds. Despite an eradication programme in Denmark, levels of infection have not decreased and suspicion has fallen on the common starling Sturnus vulgaris as a potential vector between herds. The number of breeding starlings in Denmark declined by 60% between 1976 and 2015, a trend correlated with decreases in the number of cattle grazing outside. Ironically, more starlings are now coming into Danish cattle sheds to feed on maize silage outside the breeding season, so it is increasingly important to understand the role of starlings in dispersing Salmonella between cattle herds. We caught and tested 394 different starlings at seven separate dairy farms infected with Salmonella Dublin by swabbing breast feathers, legs, feet and undertail coverts as well as taking faecal samples at these and four other infected farms. We found no trace of the pathogen, indicating that starlings are highly unlikely to be significant in spreading Salmonella Dublin between Danish cattle herds. We recommend investigating alternative contacts that may occur between herds as the cause of disease spread.

Bovine mastitis poses a significant threat to dairy production worldwide. Among the various etiologies of mastitis, Escherichia coli is a predominant environmental pathogen. Antibiotic-resistant E. coli poses substantial challenges for treating mastitis and is a threat to public health, necessitating the exploration of alternative therapeutic strategies. We studied bacteriophages as a potential alternative therapy for bovine mastitis-associated E. coli. We isolated 37 bacteriophages infecting E. coli, and characterized them for host range, growth kinetics, morphology, stability, genome fingerprinting and genome sequencing and analysis. The phages lysed between 4% and 62% of the E. coli isolates tested. Notably, 30 phages lysed bovine mastitis-associated strains. The 10 best phages selected based on host strain specificity revealed latent periods ranging from 50 to 90 min and burst sizes between 7 and 69 PFU/mL. Based on their shorter latent period and larger burst size, seven phages were subjected to transmission electron microscopy, which revealed their myovirus and siphovirus morphologies. Restriction fragment length polymorphism (RFLP) analysis of the same seven phages indicated six different patterns. The seven phages were stable at temperatures ranging from 4°C to 50°C, and at pH values ranging from 3 to 9. Whole-genome sequencing and analysis of the six phages, which showed unique RFLP patterns, predicted a lytic lifecycle, with no sequences encoding toxins or antibiotic-resistance genes. Importantly, these six phages were able to lyse multidrug-resistant and extended β-lactamase (ESBL)-producing E. coli under in vitro conditions and mastitis-associated E. coli in milk. Additionally, three phages belonging to different genera did not exhibit toxicity to mammalian cells. This study underscores the potential of bacteriophages as alternative therapeutic agents for E. coli-associated bovine mastitis. Our study has broader implications for udder and animal health, as well as the production of quality milk and dairy products, and food safety and security.

The lactation curve expresses the pattern of milk production throughout the lactation period. Such a curve provides insights to assist in designing proper management strategies. Culling dairy cows directly influences the farm economy and animal welfare. The lactation curve components (LCC) of culled Holstein cows, compared with those of retained cows, have not been studied. This study aims to investigate the LCC in culled Holstein cows compared with those retained unculled in the same herd. This research included 27,297 complete lactation records for Holstein cows described as retained or culled for low milk yield, reproductive disorders, udder problems, metabolic disorders, locomotive problems, endemic diseases, respiratory diseases and unknown reasons. The incomplete gamma function was fitted to estimate LCC, as represented by initial milk yield (IMY), the rate of milk increase to peak, the rate of milk decline after peak, peak yield (PY), time to reach peak and persistency. The general linear model was applied to analyse the effects of stayability class (retained/culled) on LCC. Cows culled for reproductive disorders showed no significant differences in LCC compared to retained cows, but they spent more days in milk (54.9 weeks) than retained cows (48.9 weeks). Except for those with reproductive disorders, all culled cows exhibited shorter lactation lengths, higher rates of milk decline after peak, shorter times to attain PY and lower persistence than retained cows. In addition, cows culled for metabolic disorders exhibited higher initial milk (35 kg) and peak milk yields (44.2 kg) than the retained cows and those culled for other reasons. In conclusion, by linking culling causes to milk production trends, this research equips farmers to identify risks earlier, such as tracking milk decline onset and adapting management to retain healthier, high-value cows longer. This strategy could reduce costs, enhance milk output and improve herd welfare on dairy farms.

Biofilm formation is a prevalent contamination source in the dairy processing industry. It enhances the tolerance of bacterial cells and elevates the risk of product spoilage. Moreover, biofilms can present significant challenges to dairy processing equipment, thereby threatening the safety and efficiency of operations. In the dairy product processing environment, biofilms typically appear as mixed biofilms. Compared to single-species biofilms, mixed biofilms are characterized by high diversity, complex spatial distribution, strong antibiotic resistance and high adaptability to environmental conditions. Consequently, it is essential to comprehensively understand the formation mechanisms and characteristics of mixed biofilms and develop effective control strategies. This review provides an overview of the formation of common microbial biofilms and their mixed biofilms during dairy processing, describes the cellular interactions and characteristics, and finally outlines current common biofilm control measures. All of these efforts aim to provide valuable insights for reducing risks associated with mixed biofilms in the dairy environment.

Fermentation and storage are known to enhance the production of natural antioxidative and angiotensin-I converting enzyme (ACE)-inhibitory components in dairy products. In this study, the antioxidative potential (% ABTS and % DPPH inhibition) and ACE-inhibitory activity of fermented skim milk (fermented at 42°C for 24 h) using 10 Lactobacillus isolates, previously isolated and characterized from the traditional sweet curd of West Bengal, India were evaluated over a storage period of 7 days at 7 ± 2°C. Among all isolates, Lactobacillus delbrueckii subsp. indicus (JSL₂P₂) exhibited the highest functional activity, with ABTS and DPPH inhibition levels of 14.57 ± 0.67% and 14.43 ± 0.72%, respectively, and ACE inhibition of 47.86 ± 1.95% after 24 h of fermentation. These bioactivities further increased during storage. The findings scientifically validate the health-promoting properties of traditional Indian sweet curd prepared with Lactobacillus delbrueckii subsp. indicus, highlighting its potential for commercial application in functional dairy product development and its role in reducing the risk of lifestyle-related diseases.