Effect of Feeding Whole or Cracked Barley Grain Accompanied by Soybean Meal or Urea on Nutrients Digestibility and Parameters of Rumen in Mehraban Sheep

This research was conducted to investigate the effects of feeding of barley grain (whole or cracked) combined with two different protein sources (urea or soybean meal) on nutrients digestibility and rumen parameters (pH and ammonia concentration). Four rumen fistultated Mehraban sheep was used that the mean body weight of sheep was 36.5±0.5 kg. The the experiment was conducted in change over design with four periods of 14 days (4 × 4). Four different experimental diets were; 1) whole barley grain (%70) with urea (T1), 2) cracked barley grain (%70) with urea (T2), 3) whole barley grain (%70) with soybean meal (T3) and 4) cracked barley grain (%70) with soybean meal (T4). DM, OM, and CP digestibility were not affected by treatments but digestibility of neutral detergent fiber (NDF) was affected by treatments with the highest value obtained for soybean fed animals (P<0.05). Although average rumen pH was not different among treatments, determined pH on 2 h after feeding was differed among treatments (P<0.05). Also, urea supplemented diets increased ammonia concentration compared to soybean meal fed diets. The rumen ammonia concentration for treatments T1 and T2 increased dramatically for both hours 2 and 3 after feeding. So, protein source supplementation has more effects on digestibility compared to processing methods and soybean meal showed greater digestibility compared to urea. More over cracking the barley did not affect nutrients digestibility and only showed some effects on rumen parameters.