INFLUENCE OF BETAINE AND ZINC SUPPLEMENTATION ON MILK PRODUCTION AND ITS COMPONENTS THERMOREGULATORY RESPONSES, BLOOD CHARACTERISTICS AND REPRODUCTIVE PERFORMANCE OF LACTATING COWS IN ARID SUBTROPICAL REGIONS

Abstract

The present study was conducted to investigate the impact of betaine (Bet) and Zinc sulphate (Zn) supplementation on milk production, blood parameters, and reproductive efficiency of cows during heat stress (HS). Cows were categorized into three groups as control group, Zn and Bet groups each group have six animals. Control group was fed a basal diet, whereas Zn and Bet groups were supplemented with either 200 mg/h/d Zn or 50 g/h/d Bet, respectively. Physiological parameters such as respiration rate (RR), pulse rate (PR), and body temperature (BT) were recorded. Blood samples were collected to estimate hemato-biochemical parameters and total anti-oxidant capacity (TAC). Milk yield and its chemical composition was recorded and analyzed weekly. The first service of conception rate, number of services per conception (NCR) and conception rate (CR) were recorded. Estradiol (E2) and progesterone (P4) hormones were measures. Results showed Bet and Zn groups led to decrease rectal temperature (RT), BT, RR and PR. However, Hemoglobin concentration (HB) increased significantly in treated cows, while hematocrit (HCT) elevated (P<0.05) by Zn supplementation. Bet and Zn groups increased significantly total proteins (TP) and globulin, while decreased (P<0.05) alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST). The TAC in Zn and Bet groups was increased significantly compared to control group. Our study showed a significant increase in CR, E2 and P4 hormones in cows treated with Bet and Zn compared to the control. It was concluded that supplementation of Zn and Bet in the diet of cow's results in significant improvement in lactation and reproductive performance during HS.