Effect of feeding different levels and sources of bypass protein with urea treated wheat straw on performance of crossbred (Holstein Friesian x Deoni) calves

An experiment was conducted to assess the effect of different levels and sources of bypass protein either with 4% urea treated or untreated wheat straw on performance of 18 crossbred (Holstein Friesian x Deoni) calves (12.44±0.48 m age;116.88±3,07 kg). One balanced concentrate mixture (CM) with RDP to UDP ratio of 65:35 was compounded and fed to the calves in control group C with untreated wheat straw ad libitum. Calves in experimental groups T₁ and T₂ were fed ad libitum urea treated wheat straw with decorticated groundnut cake and un-decorticated cottonseed cake having RDP to UDP ratio of 78:22 and 52:48, respectively. Voluntary feed intake in groups T₂ and C was statistically similar (4.90 and 4.19 kg per day, respectively) but was significantly (P<0.01) higher as compared to T₁(3.07 kg). Significantly (P<0.01) higher average daily gain (568g) was recorded for calves in group T₂ as compared to C (383.2g) and T₁(399.8g). Feed efficiency (kg DMI per unit gain in BW) of calves in groups T₂ (7.32) and T₁ (7.92) was significantly superior (P<0.05) over group C (11.36). The digestibility coefficients of DM, OM and EE were significantly (P<0.01) higher for ration T₁ and T₂ as compared to ration C. Digestibility of CP, ADF and NDF were similar for ration T₁ and T₂ but the values were significantly (P<0.01) higher than that of ration C. Digestibility of crude fiber on ration T₂ was significantly (P<0.05) higher as compared to T₁ and C. The post feeding blood urea nitrogen level in calves of group T₂ was significantly (P<0.01) lower as compared to those in C and T₁. The cost of composite ration per kg gain in body weight for calves in groups C, T₁ and T₂ were found to be Rs. 24.85, 17.55 and 15.95, respectively, indicating economic superiority of T₂ over C and T₁. The results revealed that urea treatment of wheat straw improved the nitrogen content, voluntary feed intake and the digestibility of nutrients. Feeding of crossbred calves with urea treated wheat straw based ration with un-decorticated cottonseed cake containing 48 per cent UDP, stimulated the growth rate to achieve better and economic feed efficiency in early stages of growth. The studies also emphasized the need for bypass protein content of ration in addition to CP content while expressing the protein needs of ruminants.