Vol. 12, Special Issue 11 (2023)

Author(s):
Ashish Metiya, Safi Vahora, Ashish Patel and Jigar Patel

Abstract:
The objective of this study was to explore the effect of supplementing rumen-protected methionine (RPM) and lysine (RPL) with a lower crude protein diet on apparent digestibility, nitrogen efficiency and rumen fermentation of crossbred (HF×Kankrej) female calves. In this study, twelve crossbred female calves were randomly allotted to two groups T₁ and T₂ on their body weight. The duration of the experiment was 98 days. Calves in T₁ were fed basal TMR to meet the nutrient requirement as per ICAR (2013) ^[7] standard and in T₂ were fed with TMR with 2% less CP than the T₁ group plus 2 g/kg DM RPM and 6 g/kg DM RPL. At the end of the experiment, the digestibility coefficient of DM was significantly (p<0.05) reduced in T₂ groups compared to T₁. However, the T₁ and T₂ groups did not differ with respect to the digestibility coefficient of OM, CP, EE, CF and NFE. The average DCP (%) during the digestion trial was significantly (p<0.05) lower in T₂ group compared to T₁. The average fecal N excretion (g/d) and N intake (g/d) were significantly (p<0.05) reduced in the T₂ group compared to T₁. The percent fecal nitrogen excretion as N intake (N efficiency) was significantly (p<0.05) lower in T₂ compared to T₁ resulting better nitrogen efficiency in reduced crude protein diet supplemented with RPM and RPL. Total volatile fatty acid and Total nitrogen concentration in strained rumen liquor were significantly decreases in T₂ compared to T₁ without affecting TDN value of the diet showing the beneficial effect of reduced CP diet supplemented with RPM and RPL.