Influence of Roughage Sources and Protected Protein in Complete Feed Block on Nutrients Utilization, Growth Performance, Microbial Protein Synthesis and Body Composition in Crossbred Calves

Crossbred (KS) male calves (18, BW 201.20 kg) were randomly divided into 3 groups of 6 each. Calves in group T1 were fed wheat straw (WS) based complete feed block (R:C, 60:40) while those in group T2 were fed feed block in which 40% of WS of T1 was replaced with dried sugarcane bagasse (SB) and those in group T3 were fed complete feed similar to group T2 except that its rapeseed cake was replaced with that treated with formaldehyde (1.2g/100g CP) as a source of protected protein. The complete feed blocks (CP12%, TDN 55%), manufactured at 3000 psi at dwell time of 30 sec., were fed ad lib for 4 months along with 2 kg freshly chopped maize fodder daily. Total DM intake, average daily gain in body weight and feed conversion efficiency were higher in group T3 than in groups T1 and T2, but differences among groups were not significant. DM digestibility was not influenced by 40% replacement of WS with SB, however, it was reduced (P<0.05) on incorporation of protected rapeseed cake in feed block. Feeding of feed blocks T1 resulted in higher (P<0.05) OM digestibility than those of T2 and T3, however, NDF, ADF and cellulose digestibility was lower (P<0.05) in groups T2 and T3 than in group T1. CP digestibility in groups T2 and T3 was numerically higher than in group T1. Ca and P balances were improved by the incorporation of SB as well as protected rapeseed cake in complete feed blocks, however, Ca and P retention as percent of intake remained similar amongst the groups. Nitrogen utilization, microbial-N supply and body composition of calves remained uninfluenced by dietary treatments. It was concluded that replacement of 40% WS in complete feed block with SB was economically advantageous, but replacement of rapeseed cake witrh protected rapeseed cake did not yield any improvement on the performance of crossbred calves.