Effects of Beta-carotene Administration on Fertility in Lactating Dairy Cows

Abstract

Background: Beta-(beta-) carotene, is the precursor to vitamin A, in particular, has some potential benefits on reproduction. The main objective of this study was to investigate the efficacy of beta-carotene administration on fertility following either prostaglandin F2 alpha (PGF) induced estrus or Ovsynch protocol in lactating dairy cows. Methods: Cows with at 47 +/- 3 postpartum days were divided into two groups: beta-carotene group (beta C, n=139) was treated with injectable beta-carotene while untreated cows served as control (CON, n=227). In both groups, PGF was administered and heatmount detectors were applied at 54 +/- 3 days postpartum. Cows detected in estrus after PGF were inseminated. Cows that had not been detected in estrus were divided into two groups 7 days after PGF administration; beta C-ovs (n=137) and CON-OVS (n=89). Ovsynch protocol was initiated 4 days after beta-carotene administration. Result: The estrus detection rate was similar between the beta C and CON groups (P = 0.19). Pregnancy per AI (P/AI) on d 31 was also similar between groups (P = 0.93). In the Ovsynch protocol, ovulation to the first GnRH and ovulatory follicle diameter at the time of insemination did not differ between groups. No difference was observed in P/AI at d 31 (P = 0.13). The results of this study indicated that beta-carotene administration had no effect on fertility either PGF induced estrus or Ovsynch protocol in dairy cows.