In dairy cattle farming, many traits are included in the breeding goal simultaneously to maximize economic value. The phenomenon of genetic correlations can both enhance and hinder the response to selection and has to be taken into account in multitrait selection schemes. To investigate the genetic architecture of traits included in the balanced breeding goal in Germany, multitrait meta-analyses of 11 health and 22 conformation traits in 100,809 to 180,217 German Holstein cows were conducted, followed by the estimation of global genetic correlations between each pair of traits.

Kernza straw (KS) is a high-fiber, low-energy byproduct of intermediate wheatgrass (Thinopyrum intermedium [Host] Barkworth & D.R. Dewey) that may serve as an alternative forage to increase dietary fill and reduce the risk of over-conditioning in late-pregnant heifers. We hypothesized that inclusion of KS in the diet of late-pregnant heifers would reduce feed intake and BW gain, nutrient digestibility, and urinary N excretion, but increase enteric methane production depending on the level of inclusion.

The objective of this study was to investigate the mechanistic effects of different milk-derived substrates, cow milk, goat milk, and whey protein concentrate (WPC), on the structural development, microbial succession, and metabolite production of kefir grains during 28 d of continuous subculturing. Kefir grain morphology, microbial community dynamics, and substrate-driven metabolic shifts were analyzed using scanning electron microscopy, culture- and sequencing-based microbial profiling, and untargeted metabolomics.

The aims of this study were to (1) investigate the relationships between prepartum body condition, metabolic status, dam milk variables, and colostrum yield and its immunological and nutritional components; (2) investigate the relationships between colostrum variables of dams and female offspring's growth and metabolism from birth to weaning, from weaning to calving, and during the first 100 DIM; and (3) evaluate the correlation between dam colostrum variables and their offspring after their first calving.

The objective of this study was to evaluate the effects of nitrate and Acacia mearnsii bark extract (AMT) supplementation; the latter with and without additional rumen-protected rapeseed meal (RPR), on performance, enteric CH4 emissions, and N partitioning in dairy cows fed a low-CP diet. The additional RPR aimed to counteract tannin-caused depressions of protein digestibility and potential reductions in milk production. Following a 2-wk covariate period, 18 multiparous Holstein cows were subjected to a split-plot design, with 2 main plot treatments (0.67% nitrate in dietary DM or isonitrogenous urea) and 3 subplot treatments arranged in a 3 × 3 Latin square: (1) a corn-silage-based control diet (CON; average 14.3% CP in DM), (2) CON supplemented with 3% of DM AMT containing 60% tannins (AMT), and (3) the AMT diet with an additional 6.4% of DM RPR (AMT+RPR).

The aim of this study was to characterize organic dairy systems in Brazil. It was hypothesized that the production level of the herd influences the productivity and marketing aspects of organic milk production systems. A descriptive analysis was carried out in which the variables were geographical location, herd size, animal production, feed used, health and reproduction management, organic inputs used, feed production management, and transportation of products. The characteristics of the systems were evaluated according to the level of production, with farmers divided into 3 groups, with the upper extract comprising farms with an average production of over 16 L/cow per day (HIG), the medium extract with a production between 10.5 and 16 L/cow per day (MED), and the lower extract with an average production of less than 10.5 L/cow per day (LO).

Calves that survive and thrive are important to the productivity of dairy herds through their role as potential herd replacements or as a source of livestock trading income. Conversely, calf losses are costly, leading to poorer farm productivity and welfare outcomes. Stillbirths (SB) are calvings where the calf dies near birth. Preweaning mortality (PWM) describes calves that are born alive but die before weaning. Improving SB and PWM can be achieved through conventional quantitative trait selection strategies, but these traits, especially SB, can sometimes occur because of a single large-effect recessive deleterious mutation.

Type 2 diabetes (T2D) is a global metabolic disorder influenced by diet. While cheese consumption has been suggested to protect against T2D, the mediating metabolic pathways remain unclear. Using Mendelian randomization (MR), we analyzed genetic variants associated with cheese intake (UK Biobank) and their effects on T2D risk (FinnGen) via 249 metabolites. Instrumental variables were selected under stringent criteria. Causal estimates were derived via inverse-variance weighted method, with sensitivity analyses (MR-Egger method) and mediation testing.