Optimumization of Urea Treatment of Wheat Straw and Effect of Feeding Urea Treated Paddy Straw on Intake and Digestibility of Nutrients

Two experiments were conducted in this study. In experiment 1, wheat straw was treated with 4 levels of urea (3, 4, 5 & 6%), 3 levels of moisture (30,45 & 60%) and kept for 4 periods (0,1,2 & 4 weeks reaction) to determine the optimum conditions viz. level of urea, moisture and period of reaction for treatment of wheat straw. The nylon bag dry matter digestibility (NBDMD) of as such and oven dried straw and total -N were determined in treated straw kept for different reaction periods. The maximum NBDMD was found at 5 per cent urea level with 4 weeks reaction time for undried straw. Considering the nitrogen content as well as NBDMD, 5 per cent urea with 45 per cent moisture for 4 weeks reaction time, were best combination for treatment of wheat straw. In experiment 2, eighteen crossbred heifers (7–12 m) were randomly divided into 3 equal groups. Animals were fed 3 diets in different groups (T: untreated straw supplemented with 5% prea T, restricted quantity of 5% urea treated rice straw quantity equal to DM intake of untreated straw as in T and T 5% stacked urea treated rice straw ad lib. In addition to untreated/treated paddy straw each animal was given cotton seed cake to SUDDIV 1/3^ri of crude protein requirement. Two kg green Jowar 30 g mineral mixture and 30 g common salt were also fed daily to all animal. Results indicated that drv matter digestibility (DMD) of treated paddy straw ration fed ad lib. was not different from untreated straw ration however values were significantly (P<0.05) higher in T and T in comparison to treated straw fed in restricted quantity in T. Similarly the digestibility of NDF and ADF was also not different between untreated and treated paddy straw fed ad lib. while the CP digestibility of treated straw fed ad lib. was lower (P<0.05) in comparison to untreated urea supplemented straw. The voluntary intake of dry matter and digestible dry matter of urea treated paddy straw fed ad lib. was higher (P<0.05) than untreated paddy straw supplemented with urea or treated straw fed in restricted amount, urea-NH treatment of straw increased the voluntary intake from 3.12 to 4.02 kg/100 kg body weight. It can be concluded that urea-NH treatment of paddy straw is useful in increasing the voluntary intake of nutrients in crossbred heifers.