​Effect of Beta-carotene Supplementation on Plasma Carotene Content and Fertility of Lactating Crossbred Sahiwal Cows

Abstract

Background: Beta-carotene (BETA) is a precursor of retinol (Vitamin A) and positively influenced on reproductive efficiency in cows. The aim of the study was to determine the effect of orally supplementation of beta-carotene on plasma carotene content and fertility rate of lactating crossbred Sahiwal cows. Methods: Twenty-four disease-free lactating crossbred Sahiwal cows with a close date of calving were randomly divided into two homogeneous groups for Control group (CONT; n = 12) and Beta-carotene group: 500 mg/cow/d (BETA; n = 12) from 7 days post partum (dpp) until 105 dpp thereafter on concentrations of beta-carotene and selected protein and energy parameters in plasma were determined. In addition, effects on fertility rate were studied. Result: Beta-carotene concentrations increased in plasma of beta-carotene (BETA-group) supplemented cows compared to control (CONT-group) cows (p less than 0.001). In BETA-group cows, urea concentration in blood plasma decreased significantly compared to cows of CONT-group (p less than 0.001) but did not differ in total protein, albumin, glucose and total cholesterol content in cows of both groups. Occurrence of first post partum estrus decreased (p less than 0.001) in beta-carotene (BETA-group: 74 dpp) cows compared to control (CONT-group: 81 dpp) cows. In this study, it was observed that the overall conception rate was higher (p greater than 0.001) in BETA-group: 83.33% (cows pregnant: 10/12) and lesser in the CONT-group: 50.00% (cows pregnant: 6/12). The results of this study indicated that oral supplementation with beta-carotene increased the concentration of beta-carotene and decreased the concentration of urea in plasma and cows with higher blood plasma beta-carotene content improved fertility over cows with lower blood plasma beta-carotene content.