Effect of Different Energy Sources on Feed Fermentation and Nutrient Utilization in Sheep Fed Mustard Straw Based Complete Diets

The study was conducted on 20 yearlings Bharat Merino rams, divided randomly into 4 groups of 5 animals each. Four complete diets were prepared using two types of mustard straw (untreated, UMS: 60% or 2% sodium hydroxide treated, TMS: 60%) as roughage source and two energy sources (barley, BR: 10% or molasses, MOL: 10%). The feeding was continued for 28 days followed by 7 days metabolism trial. Dry matter intake from complete diets containing TMS was higher (36%) than those contained UMS. Intakes of organic matter, crude protein and cell wall constituents were also higher (P<0.05) in TMS based diets than that of UMS based diets. The energy source in the form of molasses or barley did not have any effect on the intake or digestibility of nutrients. The rams fed on TMS based diets had higher (P<0.01) rumen pH than those on UMS containing diets. Addition of molasses in the diet favoured the production of propionate and butyrate in the rumen of sheep. The production of microbial nitrogen as percent of total rumen nitrogen was facilitated both by alkali treatment and addition of barley in the diets. It is inferred that treatment of mustard straw with alkali improved intake of dry matter and other nutrients. In the same way addition of energy in the form of molasses enhanced rumen fermentation with high rumen total-N and NH₃-N.