Effect of energy source on some hydrolytic enzymes activities in different fractions of rumen liquor and N retention in sheep fed diet containing heat-processed broiler litter

This research was carried out to investigate the effect of adding different energy sources (i.e., corn, barley and molasses) into diet containing heat-processed broiler litter (HBL; as nitrogen supplement) on activities of some ruminal hydrolytic enzymes in different fractions (i.e., particulate material, extra cellular or cellular) of rumen liquor and nitrogen retention in sheep. The assessed enzymes were included carboxymethyl-cellulase, microcrystalline-cellulase, filter paper degrading activities and α-amylase. Fifteen Moghani male sheep were used in a completely randomized design with three treatments and five replicates. The experimental diets were corn diet (alfalfa, wheat straw, HBL, corn grain), barley diet (alfalfa hay, wheat straw, HBL, barley grain) and molasses diet (alfalfa, wheat straw, HBL, molasses). For carboxymethyl-cellulase and filter paper degrading activities, the particulate material, extracellular, cellular and total (sum of all of three fractions) activities were higher (P<0.05) in those sheep fed diet contained molasses compared with other treatments. Moreover, the particulate material, cellular and total α-amylase activities and nitrogen retention enhanced (P<0.05) in molasses diet than starchy (corn or barley) diets. Dietary treatments had no effect (P>0.05) on microcrystalline-cellulase activity. Overall, results of this study showed that supplementing HBL containing diet with molasses increased the activities of rumen hydrolytic enzymes and nitrogen retention in sheep.