Dairy productivity of cows - daughters of bull producers

Abstract

In the Sverdlovsk region, in herds of Holstein black-and-white cattle of the Ural type, up to 98% of cows are descended from bull producers of foreign selection. Assessment of the influence of a bull producer on the productive qualities of daughters is relevant and of practical importance, especially in conditions of increased blood in the Holstein breed. The daughters of the breeding bull Gavano had the highest indicators in terms of milk production, the daughters of the breeding bull Das were in second place. It should be noted that the milk yield for 305 days of lactation in all studied animals was within the range of 6583 (daughter of bull Cassio) - 8106 (daughter of bull Gavano) kg, which indicates a high potential for productivity in the cows of this herd. The superiority of the daughters of bull Gavano in milk yield ranged from 445 to 1523 kg or 5.5 - 18.8% and was reliable in favor of the former (P≤0.05 - P≤0.01). The highest rates for fat mass fraction in milk were found in the daughters of bull De-Su. 4,0 and 4,01% of fat was in milk of cows-daughters of the Sayan, Mers and Cassio bulls. In terms of protein mass fraction in milk, cows differed from bull De-Su for the worse. In the milk of cows-daughters of other bull producers the protein mass fraction was in the range of 3.13-3.17%. The yield of milk fat and milk protein was more influenced by milk yield in 305 days of lactation. Most of the nutrients were obtained from the milk of the cows-daughters of bull Gavano. The daughters of bull Sayan were in second place, only slightly inferior to them were the daughters of bulls Das and De-Su. Less nutrients were obtained with milk from the daughters of bull Cassio. All cows had a dairy production direction, as evidenced by a high milk yield ratio from 1186 to 1432 kg of milk per 100 kg of live weight of a cow. The farm uses daughter cows from Holstein bull producers with a high genetic potential for productivity.

Influence of kappa-casein genotype on milk yield of cows and on culling of cows

“…A large array of Holsteinized black-and-white mottled cattle was derived in many regions of our country. Those breeds differ among themselves in economically useful traits and exterior features; the differences and features are related to the breeding zone and breed resources used in the crossing [7][8][9][10][11][12].…”

“…(7)(8) 2022 Agrarian science Аграрная наука ISSN 0869-8155 (print) ISSN 2686-701X (online) BREEDING, SELECTION, GENETIC РАЗВЕДЕНИЕ, СЕЛЕКЦИЯ, ГЕНЕТИКА…”

Dynamics of reproductive qualities of cows depending on the productive longevity

“…Food safety in any country imposes large challenges for farmers to increase production and improve the quality of agricultural products, including those of animal origin [1][2][3][4][5]. Great importance is referred to the development of dairy farming as a branch of animal husbandry, where the national economics gets milk -the valuable food product and raw material for the food industry [6][7][8][9]. For its production, highly productive dairy cattle are used; the main livestock is represented by related breeds of Dutch origin -Holstein, black-and-white mottled, etc.…”

“…For its production, highly productive dairy cattle are used; the main livestock is represented by related breeds of Dutch origin -Holstein, black-and-white mottled, etc. [8][9][10][11][12].…”

“…(7)(8) 2022 Agrarian science Аграрная наука ISSN 0869-8155 (print) ISSN 2686-701X (online) PRIVATE ZOOTECHNICIAN, ANIMAL NUTRITION…”