Effect of urea supplementation to urea molasses mineral block (UMMB) lick on nutrient utilization and rumen fermentation pattern in crossbred cattle

The effect of incremental urea supplementation on intake of urea-molasses m ineral blocks (UMMB), nutrient utilization and rumen fermentation was inves tigated on 16 adult crossbred cattle. They were divided into 4 equal groups following a completely randomized design. Animals were offered wheat straw and UMMB lick ad lib, and crushed maize grains to meet out the energy requ irements. In addition to this, animals in groups 1 to 4 were offered urea @ 0, 15, 30 and 45 g/animal a day, respectively. A metabolism trial of 6 day s duration was conducted. Results revealed that intake and digestibility of all the nutrients were alike except that CP intake was significantly (P<0. 05) more in urea supplemented groups. However, the intake of UMMB was highe st in group 2 where urea was supplemented @ 15g/day. Balances of N linearly increased due to various levels of urea supplementation. A fermentation st udy was carried out on 4 rumen fistulated adult cattle following 4 x 4 lati n-square design. Strained rumen liquor was collected and analyzed for pH, a mmonia nitrogen, total-N, TCA precipitable-N, rumen fluid volume and rumen fluid flow rate. Total N, ammonia-N and TVFA were significantly affected du e to urea supplementation. There was no significant change in various blood biochemical constituents. It can be concluded that 15g urea supplementatio n is sufficient to maintain the optimum intake of UMMB and fermentation pat tern.