Effect of different planes of nutrition on urea molasses mineral block intake, nutrient utilization, rumen fermentation pattern and blood profile in Murrah buffaloes (Bubalus bubalis)

In order to investigate the effect of plane of nutrition on intake and nutrient utilization from urea molasses mineral block (UMMB), rumen fermentation pattern and blood biochemical constituents, 20 intact and 12 rumen fistulated male Murrah buffaloes aged about 3 years and weighing 320.3±13.11 kg were randomly distributed into four groups of eight animals in each, thus each group having five intact and three rumen fistulated buffaloes. All the animals were fed individually for 40 days. Animals in group I (control) were fed ad libitum wheat straw alone along with mineral mixture and common salt, group II, III and IV were given ad libitum wheat straw alongwith increasing levels of energy from UMMB alone (group II), UMMB+700 g concentrate mixture (group III) and UMMB+1400 g concentrate mixture (group IV). Crushed barley fortified with mineral mixture and common salt was the concentrate mixture used. At the end of feeding trial, a metabolism trial of 7 days duration was conducted on intact animals to determine the digestibility of nutrients. Rumen fermentation study was carried out on 12 rumen fistulated animals following the metabolism trial, blood was collected from intact animals to estimate the nitrogenous constituents in blood serum of animals fed on different planes of nutrition. The intake of total dry matter (DM) and total digestible nutrients (TDN) was non-significantly and intake of digestible crude protein (DCP) was significantly (p<0.01) higher in treatment groups over control group. Apparent digestibility of DM, organic matter (OM), and crude protein (CP) increased significantly (p<0.01) in group II to IV over group I, whereas, the digestibility of neutral detergent fibre (NDF), acid detergent fibre (ADF), cellulose and hemicellulose tended to be higher in UMMB fed groups. Nitrogen intake and its balance increased significantly (p<0.01) with the increase in plane of nutrition. Significantly (p<0.01) higher concentration of total volatile fatty acids (TVFA), total nitrogen (TN) and its fractions were observed due to increased plane of nutrition. The rumen pH reduced significantly (p<0.01) due to concentrate feeding in group III and IV, but rumen fluid volume and digesta flow rate were unaffected. The concentration of blood serum urea increased significantly (p<0.01) in experimental groups as compared to control but ammonia–N and total protein concentrations were unaffected due to feeding of animals on different plane of nutrition. Results indicated that additional energy supplied through concentrate in group III and IV, respectively, resulted in higher intake of protein and energy than the maintenance requirement (Kearl, L.C., 1982. Nutrient Requirements of Ruminants in Developing Countries. International Feed Stuffs Institute, Utah State University, Logan, UT, 82 pp), whereas wheat straw supplemented with UMMB was sufficient to meet the maintenance requirements of adult buffaloes. Higher plane of nutrition did not have any positive effect on intake of wheat straw and UMMB.