Fermented Rice Straw as a Source of Nutrients for Ruminants

The study was undertaken to assess the effect of fermented (FRS) and unfermented rice straw (RS) based complete diets on the rumen metabolites and availability of nutrients in buffaloes. Adult male buffaloes (10; 441.37±34.62 kg BW) divided in to 2 equal groups were offered either unfermented rice straw supplemented with high protein (CP 21.2%) concentrate mixture or fermented rice straw supplemented with low protein (CP 17.1%) concentrate mixture. Simultaneously, rumen studies were conducted on 3 rumen fistulated male buffaloes which were offered one diet at a time. Bacterial and protozoal population in the rumen of animals fed FRS was higher than those fed RS. The dry matter intake and digestibility of nutrients were higher (P<0.01) in animals fed fermented rice straw as compared to those fed unfermented rice straw. The low ammoniacal-N concentration (P<0.05) in the rumen of animals fed fermented rice straw, indicated efficient utilization of available nitrogen and resulted in considerably higher TCA-N concentration as compared to the diet containing unfermented rice straw. The higher nitrogen intake in the FRS group (P<0.01) animals (due to higher DM intake) was partitioned towards higher (P<0.01) faecal-N resulting in lower (P<0.05) N-retention. The study conclusively revealed that rice straw could be fed to ruminants after urea fermentation with no adverse effects on rumen profile and digestibility of nutrients. This practice would not only prevent burning of straws in the field but also add to the ever depleting feed resources.