Abstract
An experiment was carried out to assess the effect of feeding concentrate mixtures varying in bypass protein levels with urea-treated or untreated grass on the performance of twelve Red Kandhari calves (14 months of age and 78.15 kg body weight) for a period of 75 days. Dry grass was treated with 4 percent urea solution and ensiled for 30 days. The CP ($N{\times}6.25$) content in urea treated grass increased from 3.96 to 8.89 percent. Two iso-caloric and iso-nitrogenous concentrate mixtures (CM-I and CM-II) varying in RDP to UDP ratio viz., 65:35 and 55.45 were prepared. The calves in control group ($T_1$) were fed concentrate mixture-I with ad libitum untreated dry grass and those in experimental group ($T_2$) were fed concentrate mixture-II with ad libitum urea treated dry grass. The dry matter consumption in group $T_2$ was significantly (p<0.01) higher as compared to group $T_1$. The total DMI in $T_1$ and $T_2$ was 146.92 and 166.95 kg respectively, whereas the DMI per day and per 100 kg body weight was 1.94 and 2.22 and 1.90 and 2.35 kg, respectively. The average total gain in body weight (kg) and average daily gain (g) of calves in $T_2$ was significantly (p<0.01) higher as compared to those in $T_1$ the values being 28.66, 18.33 and 382.16, 244.44, respectively. Feed efficiency in terms of kg DM per kg gain in body weight was significantly (p<0.01) lower in group $T_1$ than in $T_2$. The cost of feed per kg gain in body weight for $T_2$ and $T_1$ group was Rs. 21.14, 28.22, respectively. The digestibility coefficients of DM, CP, EE, CF, NFE, NDF and ADF were 59.60, 57.50, 53.00, 65.04, 45.82, 48.48, 52.48 and 55.73 for $T_1$ group. The coressponding values were 68.78, 67.80, 59.83, 71.41, 49.93, 53.37 and 57.81, respectively for $T_2$ group. The digestibility coefficients for all the proximate principles in $T_2$ were significantly (p<0.01) higher as compared to $T_1$. However, NDF and ADF digestibilities were not significantly different. Nutritive value determined in terms of DCP and TDN for The experimental ration was significantly (p<0.01) higher than control ration, the values being 7.32 and 47.34 and 9.39 and 52.40% respectively. The blood urea nitrogen levels at 0, 3 and 6 h interval after feeding were significantly (p<0.01) lower in calves fed experiment ration as compared to control. The overall results indicated that in Red Kandhari calves an optimum growth can be economically achieved by feeding 4 percent urea treated dry and mature grass as basal roughage supplemented with a concentrate mixture containing 20 percent CP, 70% TDN and 45% UDP/bypass protein.