Indian Journal of Animal Nutrition

Four types of urea molasses mineral blocks (B₁, B₂, B₃ and B₄) were manufactured using cold process. B₁ and B₂ contained 17 percent deoiled rice bran (DORB) whereas B₃ and B₄ contained 17 percent wheat bran (WB). Further, B₁ and B₃ contained 10 percent mustard cake (MC) whereas B₂ and B₄ contained 10 percent, deoiled sunflower cake (SFC). Other feed ingredients (molasses, 55; urea, 8; calcium oxide, 4; guar gum, 2; dicalcium phosphate, 1; phosphoric acid, 1; trace mineral mixture, 1 and common salt, 1) were similar in all the four groups. These blocks (5 kg) were offered ad lib to four adult rumen fistulated Murrah buffalo steers (84 month, 500 kg) in a 4x4 latin square switch over design. Wheat straw was offered ad lib as the sole source of roughage. After an adaptation period of at least 3 weeks on each treatment, samples of rumen liquor were obtained to study nitrogenous metabolites in the rumen of buffaloes. Daily DM intake through wheat straw (kg/day) was significantly (P<0.05) higher in treatment Bl (6.525), B3 (6.510) and B4 (6.588) than B2 (5.562). The intake through UMMB (kg/day) was higher in B2 (2.24) followed by B3 (2.13), Bl (2.04\) and B4 (1.74) with a non-significant difference. Total-N, NPN, microbial-N and NH₃-N values consistently increased after offering the basal feed and water in the morning and the maximum values were recorded at 9 h of sampling. The mean values of total-N (mg/100 ml) in strained rumen liquor (SRL) were: 92.61, Bl; 95.44, B2; 102.65, B3 and 93.40, B4; and the corresponding values for NPN were 40.75,37.21,43.86 and 37.31. The mean values of NH₅-N (mg/100 ml) in SRL were 14.58, 14.42, 17.06 and 15.75 in treatments Bl, B2, B3 and B4, respectively. It may be concluded that feeding of UMMB encourages optimal fermentation and microbial protein synthesis in the rumen of buffaloes maintained on wheat straw based diet