Interaction between barley grain processing and source of dietary nitrogen on digestibility, nitrogen metabolism and microbial protein synthesis in Mehraban sheep

In order to evaluate the effect of barley grain processing and dietary nitrogen source on digestibility, microbial protein synthesis and nitrogen retention in sheep, an experiment was conducted as 2×2 factorial under a completely randomized design. The experimental diets included 1) whole barley grain urea, 2) whole barley grain soybean meal, 3) cracked barley grain urea and 4) cracked barley grain soybean meal. During the digestibility experiment, total urine of sheep was collected, and blood samples were taken at 1 and 7 hours after morning feeding at the last day. Results showed that barley grain processing decreased dry matter digestibility (from 73.82 to 71.58 percent) and organic matter digestibility (from 74.94 to 72.84 percent) of diet (P