POSTPARTUM ELEVATED Β-HYDROXYBUTYRATE AND NON-ESTERIFIED FATTY ACIDS TOGETHER OR SEPARATELY AND THEIR ASSOCIATION WITH PLASMA METABOLITES, BODY CONDITION AND REPRODUCTIVE PERFORMANCE IN DAIRY COWS

Abstract

This study aimed to assess post-partum elevated nonesterified fatty acids (NEFA) and β hydroxybutyrate (BHB), considered either togetheror separately,relative to the estrus cyclicity and first service pregnancy status of cows and their association withbody condition scores and some metabolites.Blood samples from 50 Montbéliarde dairy cowswere collected from 15 to 52 DIMto measure serum  BHB, NEFA,glucose, triglycerides, total cholesterol, urea nitrogen, total protein, aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyltransferase (γGT), calcium, magnesium, potassium, phosphorus, sodium;and progesterone concentrations.Body condition score (BCS) was assessed at calving and at each time when blood samples were taken.Cows were considered as having post-partum elevated NEFA (H-NEFA) concentration if the concentration was≥0.70 mM and post-partum elevated BHB (H-BHB) concentration if the concentration was≥1.20 mM at 30 DIM. Overall, 93.33 % of cows having an elevated BHB show an elevated of NEFA and 51.61% of cows having an elevated NEFA have not an elevated BHB. Indeed, considering postpartum elevated NEFA as a predictor of sub-clinical ketotic cows can overrateresults. Whereas, considering postpartum elevated BHB as a predictor of cows with NEB can underestimate results. Excessive BCS at calving results in increasing the risk of post-partum elevated BHB. Cholesterol, triglycerides, AST, ALT, and urea were increased in cows having elevated BHB and NEFA compared with those having elevated NEFA only or healthy cows. Further, the risk of estrus cyclicity and pregnancy rate at first insemination (P/AI) was decreased in cows having both elevated BHB and NEFA or NEFA only.