Meta-analysis to determine the effects of supplementation of niacin during the transition or lactating period on performance in dairy cows.

Niacin, a key component of pyridine nucleotides, plays a vital role in over 200 metabolic reactions, including carbohydrate, lipid, and AA metabolism. This meta-analysis aimed to evaluate the effects of niacin supplementation on lactational performance in dairy cows. We hypothesized that niacin supplementation during the transition or lactating periods would enhance the productive performance of dairy cows.

Associations of body condition score, body condition score change, and hyperketonemia with mastitis, reproduction, and milk production.

Body condition score and hyperketonemia (HYK) have been associated with diseases, fertility, and culling, but data are contradictory about their association with pregnancy loss. Our objective was to conduct a retrospective cohort study to investigate associations between BCS, BCS change (ΔBCS), blood BHB, and HYK with mastitis, pregnancy per artificial insemination (P/AI), pregnancy loss (PGL), milk yield, and risk of leaving the herd on a Michigan dairy farm that uses an automated milking system (AMS). We recorded BCS for cows prepartum (14 d before calving) and postpartum (14-21 DIM), and multiparous cows were evaluated for HYK between 3 and 7 DIM.

On-farm supplementation of rumen-protected niacin: A randomized clinical trial.

B vitamins, including niacin (vitamin B), are synthesized by rumen microbes, but supplementation may provide additional benefits for ruminant health and productivity. Supplementing rumen-protected niacin (RPN) during the transition period can reduce lipolysis after calving and, consequently, may improve health and fertility of dairy cattle later in lactation. Our objective was to determine if supplementing RPN during the first 21 DIM would improve the health of dairy cows on a commercial dairy farm.

Effects of rumen-protected niacin on inflammatory response to repeated intramammary lipopolysaccharide challenges.

Nutritional strategies that improve an animal's resilience to various challenges may improve animal health and welfare. One such nutrient is niacin, which has reduced inflammation in mice, humans, and swine; however, niacin's anti-inflammatory effects have not been investigated in cattle. Our objective was to determine whether rumen-protected niacin (RPN) alters lactating dairy cows' inflammatory response to intramammary LPS challenges, whether RPN resulted in any carryover effects, and whether repeated LPS challenges result in signs of immune tolerance or innate immune training.

Investigation of HCAR2 antagonists as a potential strategy to modulate bovine leukocytes.

Background: Dairy cows experiencing ketosis after calving suffer greater disease incidence and are at greater risk of leaving the herd. In vitro administration of beta-hydroxybutyric acid (BHBA; the primary blood ketone) has inhibitory effects on the function of bovine leukocytes. BHBA is a ligand of HCAR2 and the activation of these receptors promotes an anti-inflammatory response which may be related with immunosuppression observed in transition dairy cattle.