Effect of Supplementing Rumen Protected Methionine and Lysine on Nutrient Intake and Growth Performance of Hariana Heifers

Abstract

The use of rumen protected amino acids is becoming a common practice in Indian lactating cattle and studies on their effects on growth performance of heifers are scanty. A trial was conducted to observe the effect of rumen protected lysine and methionine on nutrient intake and growth performance in growing heifers of Hariana breed. Eighteen heifers were randomly distributed into three treatment groups: control (CTR), treatment 1 (T1) and treatment 2 (T2) on a body weight basis. Heifers in the T1 group were fed a basal ration supplemented with 1 g/d of rumen protected methionine (RPM) and 5 g/d of rumen protected lysine (RPL). Heifers in the T2 group were fed the same basal ration supplemented with 2 g/d of RPM and 10 g/d of RPL. A 6-day digestion trial was conducted at the end of a 90-day feeding study. Dry matter intake and body weight were recorded fortnightly. Average daily gain was increased by 16 and 17% (P=0.02) in T1 and T2 groups, respectively as compared with CTR. Feed conversion ratio was reduced (P<0.001) by 25 and 27% in T1 and T2 groups compared with CTR. Dry matter intake and other nutrient intake was similar among all three treatment groups during the overall trial and digestibility trial period. In conclusion, dietary supplementation of RPM and RPL improved feed conversion efficiency and growth rate of growing Hariana heifers without affecting nutrient intake.