| Popis: |
The diet of dairy bulls contains little high-quality protein. This primarily affects the main indicators of feed growth and conversion. Poor-quality protein in the diet leads to excessive formation of ammonia in the rumen. Increased concentrations of ammonia, does not participate in the synthesis of microbial protein and is excreted in the urine, which is an energy-consuming process and negatively affects the gains. Ammonia has a toxic effect, when an excessive amount of it enters the bloodstream, where it causes hyperamonymy, and creates an additional load on the liver. Aims: The aim of the study is to create an optimal structure of the diet, in which the protein will be completely utilized by the rumen microbiota and animal protein will be reproduced on its basis to create the growth potential of fattening bulls. The development of this diet will allow creating a technology for fattening steers for meat that is economically profitable with a high proportion of healthy animals with high productivity. Methodology: The studies were conducted on calves of the Kholmogorsky breed raised in the VNIIFBIP vivarium, aged from 1.5 months to 14 months. At the age of 1.5 months, the animals were intensively accustomed to the introduction of concentrates and coarse feeds. Feeding with a milk substitute was carried out up to the age of 70 days with free access to mixed feed and hay. Results: During the study, the main factors responsible for the metabolic processes in bull calves were identified. The factors of digestibility in the rumen were studied. Physiological and biochemical parameters were established to assess the reduction of the risks of hyperammonemia. The use of concentrated feed against the background of strict proportional administration together with coarse feed with intensive cultivation and fattening of dairy bulls and the normal course of enzymatic processes in the rumen and throughout the body allows you to achieve an average daily increase of up to 1420 g by 14 months of age and reduce feed conversion. Conclusion: The results obtained make it possible to increase the productivity of fattening steers in regions with a large number of dairy cattle and the availability of concentrated feed. |
