Effect of inorganic or organic selenium supplementation on nutrient intake and rumen microbial population and protein content in cattle and buffaloes

A study was conducted to monitor the effect of supplementation of inorganic or organic form of selenium (Se) on nutrient intake, rumen microbial mass and protein of microbial origin in cattle and buffaloes. For this, 3 rumen cannulated animals each of crossbred cattle (228.00 +/- 16.04 kg) and Murrah buffaloes (166.67 +/- 6.67 kg) were randomly distributed in 3 x 3 latin square (switch over) design. In treatment T-1, the animals were given a basal diet (0.456 ppm Se) consisting of maize fodder and concentrate mixture (71: 29) to meet the nutrient requirements. The animals in other 2 groups were fed on similar diets as in T-1 but were supplemented with 0.5 ppm Se either in the form of sodium selenite (inorganic Se; T-3) or selenomethionine (organic Se; T-3). The results showed no significant differences in nutrient intake, rumen bacterial and protozoal population and microbial protein among the treatments in both species. The mean DM, CP and TDN intakes were 2.29 +/- 0.07 and 2.31 +/- 0.07 kg/100 kg, 256.86 +/- 6.60 and 260.98 +/- 9.14 g/100 kg and 1.42 +/- 0.03 and 1.43 +/- 0.05 kg/100 body weight in cattle and buffaloes, respectively. Water intake was also comparable. The intake of nutrients was similar in cattle and buffaloes. However, in comparison to cattle, buffaloes showed significantly higher bacterial counts (10.74 +/- 0.45 vs. 9.51 +/- 0.67x10(9)/ml; P < 0.01), protozoal number (7.43 +/- 0.31 vs 6.36 +/- 0.31 10(5)/ml; P < 0.05) and microbial protein concentration (122.7 +/- 3.7 vs 114.3 +/- 3.5 mg/100 ml; P < 0.01) in the rumen fluid. Hence, supplementation of 0.5 ppm Se either in inorganic or organic form did not show any significant effect on nutrient intake, rumen microbial population and protein synthesis in cattle and buffaloes.