DIGESTIBILITY OF ORGANIC SUBSTANCES IN DIFFERENT SECTIONS OF THE DIGESTIVE TRACT OF BULLS WITH A REDUCTION OF THE AMOUNT OF SOLUBLE PROTEIN IN THE DIET

Abstract

On the bulls of red steppe breed with duodenal and ileocecal cannulas when feeding iso-enery and isoprotein diets with different amounts of soluble protein (SP) and degradable protein (DP) studied conversions of dry matter (DМ), organic matter (OM) and crude protein (CP) separately in the complex stomach, small (SI) and large (LI) parts of the intestine. Evaluated the nitrogen balance by the amount of protein absorbed into the SI, the losses of nitrogen with urine – by the proportion of urea nitrogen. The diet consisted of awnless bonfire hay, pea deer, and mineral supplements. Various amounts of SP in the diets were achieved by feeding natural pea dough (control) and roasted pea dough at a temperature of 105°C (experiment). In a compound stomach, the digestibility CP on the experimental diet with a reduced level of SP was by 10 % less. In the control diet with a high level of SP is more in SI received of ammonia nitrogen. In SI digestibility of DM and OM on the experimental diet are by 8–10 % more. Amounts of DM, OM and CP in LI on a control diet decreased by 5.6–7.5 %, in the experimental diet – not changed. On an experimental diet with an increased level of NSP, the SI received more nitrogen and was digested by 10 % more than in the control. The calculated nitrogen balance according to the classical scheme did not reflect the true amount of it assimilated in the body. On the control diet with an increased level of SP, there was the devaluation of the protein in the feeds and oblasting due to the larger release in urea by 40 % of the nitrogen in the form of urea.