The partial efficiency of ME used for net energy by growing ruminants is greater when fed alfalfa (ALF) than orchard grass (OG), but is unknown for lactating cows and may be influenced by varying the nonstructural carbohydrate (NSC) grain source. The NSC sources evaluated were corn grain (CG) and barley grain (BG). Individual treatments were ALF-CG, ALF-BG, OG-CG, and OG-BG arranged in a 4 × 4 Latin square having a 2 × 2 factorial arrangement of forage (FOR) and NSC sources. Four multiparous lactating Holstein dairy cows (milk = 33.8 ± 4.5 kg/d; BW = 599 ± 25.8 kg; DIM = 82 ± 20 d) were selected to measure whole-body energy balance via calorimetry.

The UK's climate and topography enables multiple different calving patterns to operate within the same market, facilitated by industry infrastructure that allows for a variety of milk purchasing arrangements. All year round (AYR) calving is most common, and with current labor challenges spring block (SB), autumn block (AB) and twin block (TB) calving systems could potentially become more popular, but research comparing the efficiency of AYR with block calving systems operating within the same market conditions is limited.

Neonatal calf diarrhea remains a major issue in terms of mortality, economic, and animal welfare losses. In addition to different infectious and pathogenic causes, nonpathogenic factors, particularly stress and nutritional and management practices, also contribute significantly to the incidence of diarrhea in calves. This study aimed to investigate changes in blood metabolites and fecal parameters (pH value, short-chain fatty acids, and triglyceride content) preceding the onset of diarrhea signs in neonatal calves.

Staphylococcus aureus, a prominent global foodborne pathogen, frequently triggers epidemics with severe public health impacts. Timely and reliable detection of S. aureus is crucial for mitigating the disease burden in low- and middle-income countries. However, conventional laboratory-based detection methods remain impractical in resource-limited settings, highlighting the urgent need for accessible point-of-care solutions. Here, we present an inner-outer-tube (IOT) assay that synergistically integrates the polymerase spiral amplification (PSR) technology for enhanced sensitivity with the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 12a (Cas12a) system for sequence-specific identification.

Mastitis represents one of the most formidable challenges in modern dairy farming, posing significant threats to individual cow health and causing substantial economic losses throughout the dairy production chain. Traditional disease diagnosis methods are often reactive and costly, creating an urgent need for advanced predictive technologies. To address these issues, we proposed a novel machine learning–based mastitis prediction system that breaks through conventional diagnostic paradigms by deeply integrating data science with veterinary medicine.

Excessive lipolysis and inflammatory response are critically involved in the pathogenesis of ketosis in periparturient dairy cows. Evidence has been growing for participation of the growth hormone (GH) in the metabolic regulation of adipose tissue. However, the potential role of GH in promoting lipolysis and proinflammatory signaling activation in bovine adipocytes remains to be elucidated. The objective of this study was to investigate the regulatory effects of GH on the lipolysis and inflammatory response of bovine adipocytes.

This study investigated the effects of varying fat levels and ratios of coconut-to-palm fat in milk replacer on solid feed intake and performance of male Holstein calves fed a high milk replacer allowance. Calves were individually housed and enrolled in a 91-d (study 1; n = 128) and 84-d (study 2; n = 128) experiment at the same research facility divided into 3 phases: preweaning (1–42 d), weaning (43–63 d), and postweaning (64-study end). In study 1, calves were randomly assigned to 1 of the 3 treatments, consisting of a milk replacer containing a spray-dried blend of 20% coconut-to-80% palm fat with: 1) low fat (17%; LF-17%; n = 42; BW = 47.64 ± 2.62 kg), 2) moderate fat (23%; MF-23%; n = 43; BW = 47.69 ± 3.42 kg), and 3) high fat (29%; HF-29%; n = 41; BW = 47.04 ± 3.74 kg) in relation to 26% CP level.

The extent of genetic variability in fatty acids in bovine milk has, to date, generally focused on its concentration in either milk or milk fat. Selection for ratio traits, such as fatty acid concentration, is statistically and biologically problematic because it can distort relationships between component traits and lead to unintended genetic responses. The objective of this study was to explore the degree of genetic variability in the total yield of individual fatty acids, including when adjusted to a common fat yield.

Replacing hexane with 2-methyloxolane (MeOx) for defatting soybean meal (SBM) requires adaptations of the SBM production process. These modifications may increase the concentration of Maillard reaction products and reduce the residual oil content in MeOx-defatted SBM compared with hexane-defatted SBM. In addition, despite desolventization, solvent residues may still be present in the SBM when fed to livestock. This study aims to ensure that the replacement of hexane with MeOx for defatting SBM does not affect the ruminal and milk fatty acid profiles nor the liver activity, liver functionality, and inflammatory status in dairy cows.

Three studies evaluated the effects of a Bacillus-based direct-fed microbial (DFM) on ex vivo fermentation traits, as well as on performance of lactating dairy cows. In experiment 1, rumen-fistulated lactating Holstein-Friesian cows (6.6 ± 2.3 parity; 630 ± 37.2 kg BW; 18.9 ± 3.35 kg milk/d) were fed an unsupplemented ration (CON; n = 5) or supplemented with 3 g/cow per d of a Bacillus-based DFM (BAC; n = 5) for 14 d before rumen sampling and subsequent ex vivo evaluation of fermentation characteristics of 2 different substrates (vetch hay [Vicia sativa] and perennial ryegrass herbage [Lolium perenne L.]).

Accurate local ancestry (LA) inference is important for genomic evaluations in admixed dairy cattle. This study had 2 main objectives: to compare the performance of 3 LA inference software: AllOr, BreedOrigin, and ChromoPainter, and to evaluate the impact of LA inference errors on genomic prediction accuracy. Two simulated admixed populations were used: a structured DairyCross population created through three-way rotational crossbreeding and a Red Dairy cattle (RDC) population representing historical admixture among multiple breeds.

The gastrointestinal tract (GIT) plays a crucial role in maintaining overall health and performance in ruminants, with the rumen functioning as fermentation chamber for plant biomass. Intestinal epithelial cells are exposed to billions of microorganisms that significantly affect the epithelial barrier by activating complex metabolic and immune pathways. The interaction between microbiota and host is mediated by signaling compounds such as metabolites and peptides, and also extracellular vesicles (EV).

The purpose of this study was to use a secondary analysis to investigate the use of feeding high and low-energy diets to alter BCS at dry-off, and to assess the subsequent changes in BCS on feed intake, calcemia, and assessment of immune function, including inflammation, during the periparturient period. Multiparous Holstein lactating dairy cows at 150 d of gestation were blocked by expected calving date and randomly assigned to receive one of 2 dietary treatments during late lactation until dry-off, aiming to maintain or decrease BCS.

Dairy cows are highly motivated to use grooming brushes, and their use promotes expression of natural behavior. Although brushes are increasingly common on commercial dairy farms, little is known about how their mechanical properties, specifically swingability and rotation, influence cattle preferences for brush use. This study investigated adult dairy cow preferences for 3 brushes identical in physical and visual features but differing mechanically: (1) swinging and rotating, (2) swinging-only, and (3) stationary (neither swinging nor rotating).