UTILIZATION OF CASTOR STRAW AS ROUGHAGE SOURCE IN COMPLETE DIETS OF GROWING CROSSBRED CALVES

Three complete diets (40 roughage and 60 concentrate) containing casto r (Ricinus communis) straw (whole plant after removing fruits) at 0,10 and 20% levels in place of sorghum straw were tested on 18 crossbred (Ongole x Holstein) male calves (5-6 months), 6 in each group using co mpletely randomized design in a growth-cum-metabolism experiment. The daily feed and water intake and fortnightly body weights were recorded . A metabolic trial was conducted at the end of 6 months growth trial. The DM intake was comparable on all the diets. However, digestibility of DM, OM and CP decreased (P<0.05) for every increase in the proport ion of castor straw in the diet. Digestibility of CF and NFE on diet 2 did not differ significantly from diets 1 to 3. In spite of decreased trend from 1 to 3, the positive N,Ca and P balances recorded on all t he diets indicate that the diets provided required quantities of these nutrients. Though the DCP and TDN were lesser than the suggested leve ls, the calves met the TDN requirements. The ADG decreased while DM in take /kg gain and cost of feed/kg gain increased for every increase in the proportion of castor straw from diets 1 to 3. These results indic ate that castor straw can be utilized as roughage source in complete d iets of growing calves up to 20% level without any deleterious effect in spite of increased cost of feed /kg live weight gain due to incorpo ration of castor straw.