Effect of Feeding Extruded Complete Diet Containing Maize Cobs in Ongole Bull Calves

Eighteen Ongole bull calves (1½ year, 158kg b.wt), distributed in 3 equal groups, were fed on: 1) control diet containing concentrate mixture and ground Maize cobs In 60:40 ratio, 2) complete diet (mash) containing 40% maize cobs and 3) extruded complete diet containing 40% maize cobs in a 180 d growth trial. Metabolic trial was conducted in mid of experiment to assess the effect of diets on nutrient utilization. The digestibilities of DM, OM (P<0.05) and CP (P<0.01) and DCP and TON contents were significantly higher on diet 1 followed by diet 2 and 3. NFE digestibility was significantly (P<0.01) higher on expander extruder processed diet compared to conventional diet. All the animals were in positive N, Ca and P balances. Average daily gain (ADG) increased (P<0.05) gradually from control to mash to expander-extruded diet. DMI intake/kg gain was significantly (P<0.05) Sower on complete diets. Cost of feed/kg gain reduced (P<0.05) on diets 2 and 3 as compared to diet 1. These results indicated that blending concentrate With roughage improved the palatability and nutrient utilization and expander-extruder processed diet had a significant effect over feeding mash diet.