Intensity of raising repair heifers under different feeding conditions

The materials of the publication reflect the results of research conducted on repair heifers of the Simmental breed in the conditions of the farm “Pchany-Denkovych” of the Stryi district of the Lviv region. The basis of the research is the task of standardized feeding of repair heifers with the same type of rations throughout the year when replacing a portion of the concentrated mixture with hay-type mono-forage. The rations of experimental animals were balanced according to detailed norms. The study was conducted on three groups of heifers with ten heads each. The analysis of the obtained results showed that different conditions of energy nutrition of experimental animals, characterizing the level of metabolism in the animal's body according to indicators of the fractional content of glutathione in whole blood, had an ambiguous effect on the development of the general physiological state. This indicator plays an important role in redox processes in the body. In particular, it plays an active part in the synthesis of proteins and is also a part of certain glycolysis enzymes. The results showed a general tendency to increase the blood glutathione content; however, this increase did not occur in one constant direction but wave-like and depended on the conditions of the feeding factor, especially the second and third research groups. If during the period of growing heifers (at the age of 8–12 months), the concentration of total glutathione of all groups was relatively low (it ranged from 19.74 to 27.02 mg%), then under the conditions of the feeding factor of the experimental groups it was set to a higher level (34.47 mg%), which indicates a positive influence of feeding conditions, namely: the use of 30 % of hay-type monoforage in the structure of the diet. So, it should be noted that our research, to some extent, reveals the biochemical basis of the growth of repair heifers depending on the feeding conditions and shows that the proposed level is as close as possible to the optimal level for repairing the young Simmental breed. Animals of this breed have a high ability to grow organisms in favorable conditions to compensate for the lag in growth and development that occurred before the age of 6 months. The positive influence of the researched feed factor was also confirmed by indicators of the enzymatic activity of rumen microflora, especially cellulolytic and amylolytic bacteria, which ensured the active synthesis of nutrients necessary for the animal body and, first of all, microbial protein, which is known to be complete in terms of amino acids. Comparing inter-group digestibility indicators, it is necessary to note the high digestibility of nutrients in the heifers of the third group, in the structure of whose diet the share of nutritional replacement of compound fodder with mono fodder was 30 %, which was associated with high activity of cellulolytic microflora of the rumen. This, in turn, positively affected the intensity of growth and development of repair heifers. Therefore, the research recommends that the farm use the developed system of feeding and repairing young Simmental breeds.