Ruminal fermentation, nutrient digestibility and microbial protein synthesis in sheep fed diets with different levels of date pulp

Abstract

Four ruminally cannulated mature Kermani sheep (50 ± 2.3 kg and 40 ± 2.1 months old) were used in a 4 × 4 Latin square design to determine the effects of diets with different levels of date pulp (DP) on ruminal fermentation, nutrient digestibility and microbial protein synthesis. DP was replaced for wheat bran in diets at no DP (0 DP), 7 (7 DP), 14 (14 DP) and 21% (21 DP) of diet dry matter (DM) and were fed twice daily (0800 hours and 1800 hours). In this study, increasing the amount of DP in diets of sheep did not affect DM intake and apparent digestibility of nutrient (P > 0.05). Inclusion of DP in diets increased ruminal pH linearly (P < 0.05), but did not influence total volatile fatty acids and molar proportion of individual volatile fatty acids (P > 0.05). Ruminal ammonia nitrogen concentration (6.04 vs 10.13 mmol/L), and blood urea nitrogen (8.59 vs 13.10 mg/dL) were affected by diets (P < 0.05). Moreover, urinary nitrogen excretion was higher (P < 0.05) for Control diet (no DP) than the 21 DP diet. In this study, urinary excretion of purine derivatives and microbial protein synthesis were affected by experimental diets (P < 0.05). In conclusion, this study showed that DP at 14% can be used as an alternative feed resource in sheep nutrition especially in semiarid areas.