High-yielding dairy cows around parturition are challenged by varying degrees of low calcium status (hypocalcemia), which is associated with increased risk of several metabolic disorders and diseases in early lactation. The aim of the present study was to investigate effects of dietary 25-hydroxycholecalciferol (25-OH-D3; calcidiol) supplementation during the transition period. Forty-two multiparous Holstein cows were fed 1 of 2 treatments: either cholecalciferol (D3) or 25-OH-D3 (HyD) as dietary vitamin D supplements.

Enterovirus eibovi (EV-E) is a bovine RNA virus with debated pathogenic potential. The aim of this study was to evaluate the in vitro effects of bovine lactoferrin (bLF), an antimicrobial and immunomodulatory glycoprotein, on EV-E–infected bovine peripheral blood mononuclear cells (PBMC). The PBMC viability, phagocytic function, and lymphocyte proliferation were examined using spectrophotometric assays. Flow cytometry was used for immunophenotyping of lymphocytes, and real-time quantitative PCR for evaluation of immune-related gene expression.

Our objectives were, in grazing dairy ewes, (1) to describe SCC, California Mastitis Test (CMT) score, and ewe-level milk aerobic plate count (APC), (2) to explore the relationship between CMT and SCC, (3) to identify risk factors for elevated APC, and (4) to find the optimal SCC threshold for diagnosis of IMI. Gland-level milk samples were collected from ∼15 randomly selected ewes on each of 20 New Zealand dairy sheep farms at early, mid, and late lactation in a repeated cross-sectional study. Aerobic bacterial culture and CMT (measured on a scale of 0, trace, 1, 2, or 3) were performed at the gland level, and SCC and APC at the ewe level using composite milk samples.

Our objectives were to describe subclinical mastitis and identify its risk factors among grazing dairy ewes in New Zealand. Gland-level milk samples were collected from ∼15 randomly selected ewes on each of 20 dairy sheep farms at early, mid, and late lactation in a repeated cross-sectional study. California Mastitis Tests (CMT; measured on a scale of 0, trace, 1, 2, or 3) and aerobic bacterial culture were performed at the gland level, and SCC at the ewe level using composite milk samples. Subclinical mastitis was defined at the ewe level as having 1 or 2 bacteriologically positive glands and SCC >500 × 103 cells/mL or a CMT score ≥1 (or both).

Methane (CH4) emissions from enteric fermentation in ruminants represent the largest source of anthropogenic agricultural emissions, contributing significantly to global CH4 levels. Enteric CH4 mitigation strategies have been intensively investigated to address the detrimental effects on climate change and ruminant production characteristics. This systematic review investigated whether microbial silage inoculants could reduce CH4 formation in the rumen microbiome, both ex vivo and in vivo, based on available literature.

Our objective was to evaluate the effect of abomasal infusions of increasing doses of docosahexaenoic acid (DHA; 22:6 n-3) on plasma and milk fatty acids (FA) and milk production of mid-lactation dairy cows. Eight multiparous ruminally cannulated Holstein cows (97 ± 37 DIM, 49.2 ± 3.3 kg/d milk) were assigned to a 4 × 4 Latin square design. Treatments consisted of abomasal infusions of 0, 2, 4, and 6 g/d of DHA with 11-d treatment periods and 10-d washout periods. The DHA was provided via an enriched algal oil (65% DHA) and suspended in ethanol (∼200 g/d).

We evaluated the effects of whole cottonseed (WCS) and fatty acid (FA) supplementation on the production responses of early-lactation cows. Fifty-two multiparous cows were used in a randomized complete block design with a 2 × 2 factorial arrangement of treatments. The following treatment diets were fed from 1 to 21 d postpartum (fresh period; FR): (1) a diet containing no WCS or supplemental FA (CON); (2) a diet containing WCS at 10% diet DM (CT); (3) a diet supplemented with a calcium salt containing 60% C16:0 and 30% C18:1 cis-9 (FAT); and (4) a diet containing WCS at 10% diet DM and a C16:0 C18:1 cis-9 calcium salt (CT+FAT).

The objective of this study was to compare the economic performances of 3 pasture-based systems: a perennial ryegrass (Lolium perenne L.; PRG) receiving 250 kg N/ha (PRG-250N); a PRG-white clover (Trifolium repens L.; WC) receiving 125 kg N/ha (PRGWC-125N); and a multispecies (MSS) sward composed of grasses, legumes, and herbs receiving 125 kg N/ha (MSS-125N). Sward and animal performances were measured over 3 years in a system-scale study involving 3 farmlets at Teagasc Moorepark, Ireland. Subsequently, based on the physical data collected, an economic performance of each sward system was evaluated using current output prices and input costs in the Moorepark Dairy Systems Model.

The objectives of this study were to (1) evaluate the You Look Only Once (YOLOv7) algorithm for group-level behavior monitoring in freestall cows, (2) propose a multitask contrastive network (MTCN) for individual cow identification from limited reference data and compare its performance to a traditional convolutional neural network, and (3) develop and validate a scalable 2-step computer vision framework integrating behavior detection and individual identification. Twenty-one Holstein cows housed in a single pen were monitored using ceiling-mounted red-green-blue cameras capturing images at 10-s intervals over 30 d.

Automated milk feeders (AMF) generate large-scale longitudinal milk feeding data in calves, providing a great opportunity for deriving the novel traits that may be included in cattle breeding programs. For group-housed dairy calves, genetic selection for social dominance could have important implications on improving animal welfare and health, optimizing management practices, and possibly improving cow performance through indirect genetic selection. In this study, we derived and estimated genetic parameters for 6 calf social dominance indicators using a dataset consisting of 4,164,960 AMF visit records from 8,632 American Holstein female calves, including 5,910 calves with genomic data for 64,767 autosomal SNPs.

Water quality plays a crucial role in calf health and performance, mainly when it is used to dilute milk replacers, which can affect the incidence of diarrhea. This study assessed the effects of municipal tap water (TW) compared with purified water (PW) on calf performance and health. Thirty Holstein calves were randomly assigned to 2 treatment groups in a randomized block design. Calves received 6 L/d of milk replacer (14% solids) diluted with the respective water treatment until gradual weaning (49–53 d).