The dissertation suggests theoretically substantiated and experimentally confirmed elements of the system of cattle raising and utilization developed for the purpose of stock growing, increasing the level of productivity and products quality. The authors established the reasonableness of feeding the heifers with colostrum with immunoglobulin content above 50 g/l on condition of consumption of 400 kg of whole milk at the milk stage, thus creating the preconditions for accelerating the calves’ growth at the age under 3 months. It has been proven, that the transition from milk feeding to the whole milk substitute from the age of 21 days provides the compensation of the negative effect of colostrum with immunoglobulin content under 50 g/l and increases the live weight of the heifers by the end of the milk stage. The authors have studied the effect of the change of heifers feeding factors at the milk stage (milk – whole milk substitute – concentrate mixture – starter feed) on their weight and linear growth at various stages of ontogenesis, the beginning of reproductive utilization and formation of milk productivity in the cows of various ages. It is established that the change of 250 of 400 kg of the whole milk in the heifers’ diet with whole milk substitute on condition of compensation of the lack of energy with the mixture of concentrates (50 % wheat + 50 % barley) does not produce negative effect on the growth of young cows, cows and heifers. Substitution of the concentrated part of the calves’ diet, that consists of the grain feed, with the starter feed is maximally efficiently combined with the whole milk feeding and increases the weight and linear growth of the cows and heifers, decreases
the age of reproductive utilization of the animals, provides the formation of higher productivity of the cows. The system of replacement heifers raising on condition of using the whole milk substitute preconditions its saving, rising the merchantability and efficacy of the milk cattle farm management. Due to its implementation, the profitability of raising the cows increases by 7,7 %, that of raising the heifers – by 21 %, and the milk merchantability rises by 1,8 %. It is established that k-casein locus heterozygosity (AB) of the cows preconditions rising of their milk yield and the content of fat and proteins of casein (k, α, β) group fracture and reduction of the content of serum fats (immunoglobulins, lactoferrin, α-lactoglobulin) in the milk and improves the breeding value of bulls in terms of milk yield and the milk fat and protein content in the daughters.
According to the study of the indices of reproductive ability of the bulls, it is established that the level of sperm productivity (ejaculate volume, spermatozoid concentration in ejaculate) of Holstein bulls depends on their individual features and pertain to a particular line. With aging of both milk and meat breed bulls, the quantitative and qualitative parameters of their sperm – ejaculate volume, motility, spermatozoid concentration, total number of spermatozoids in ejaculate, total number of spermatozoids with advanced sexual development, the number of collected sperm dozes – probably improve (on condition of reduction of rejections share).
