Taux sériques élevés des AGNE et de BHBA et leur association avec les performances de la reproduction chez la vache laitière ; Méta-analyse

Abstract

This study fit into a doctoral project . A meta-analysis including 37 different models from 14 papers was conducted to evaluate the effect of elevated non-esterified fatty acids (NEFAs) and β-hydroxylbutyrate (BHBA) on the variables pregnancy rate at first AI (FSCR), estrous cyclicity (EC), time to pregnancy. The available studies provided approximately 23 382 cows with sufficient data for analysis. For each outcome, the odds ratio (OR), relative risk (RR) or hazard ratio (HR) was presented for various moderators to reduce heterogeneity among the studies. Over all the studies analyzed, elevated NEFAs and BHBA had effect on FSCR (OR = 0.592), EC (OR=0.879), days to pregnancy (HR= 0.771). The results showed that 2 main categories of moderators had a significant effect on the adjusted risk. First, the adjustment made by defining type and time of test [High post-partum BHBA (BHB-post) and high post-partum NEFAs (NEFA-post)] for PR/AI. Second, frequency of testing [High BHBA or NEFAs in one fixed time (one) and High BHBA or NEFAs in either of the first 2 wk. postpartum (either) for EC.