The use of inbreeding in dairy cattle breeding

Abstract

In cattle breeding during breeding season, great importance is attached to the selection of male and female pairs. The purpose of the work is to assess the effect of inbreeding on the milk production of cows of different genotypes. It was found that the main number of animals in the herd was obtained using remote inbreeding, which is 83.8%. The use of related mating led to a decrease in the age of the first calving by 0.3 months, a lactation period by 0.4, and a slight increase in milk yield by 78 kg with a decrease in the mass fraction of fat by 0.01% and protein by 0.02%, relative to outbred cows. A significant change in the productive longevity of animals obtained by outbred breeding and the use of a moderate level of inbreeding (P≤0.05) was noted. The effect of blood on Holstein breed on the productive qualities of cows was also established. An increase in blood level to 75-91% led to an increase in milk yield and qualitative indicators of productivity. Thus, the average milk yield in the group increased by 566 kg or 9.4%, while increasing the mass fraction of fat by 0.04% and protein by 0.04%. The best indicators of productivity within the genotype groups were established with a remote level of inbreeding and a genotype of Holstein breed 91-97% blood. In the future, when developing a breeding plan, it is necessary to take into account the fact that the best quality indicators of productivity, namely the mass fraction of fat and the mass fraction of protein are higher in cows with a genotype from 76 to 91% and a moderate level of inbreeding - 3.97% and 3.08%.

Análisis de la consanguinidad sobre parámetros reproductivos en un rebaño lechero en costa central

“…Diversos estudios han demostrado que los efectos de la consanguinidad a la edad al primer parto, intervalos entre partos fueron significativos, que un incremento en 1% de la consanguinidad resulta en un incremento en el intervalo de partos de 1,88 días, más no la edad al primer parto (Silva et al, 2019;Makanjuola et al, 2020) y sobre características productivas también se observa un efecto de la depresión endogámica (Moradpour y Hamidi, 2019;Gorelik et al, 2020). Cassell et al (2003), determinaron que la depresión endogámica en el ganado Holstein y Jersey registrado fueron positivas (no deseables) pero no significativa para los días al primer servicio, pero si fue significativa el efecto sobre la producción de leche, observándose que por cada 1% de incremento de la consanguinidad disminuyó en -0,12 a -0,06 kg/d en el ganado Holstein.…”

Evaluating the growth of replacement heifers from different seed bulls

“…As a result, large, highly productive animals with a high genetic potential for productivity and well adapted to industrial milk production were obtained. They are able to have good average daily milk yield during the entire lactation, produce milk for a long time without a sharp decrease in milk yield; however, a decrease in reproductive capacity is noted, which put the issues of herd reproduction and rearing young stock into the first place [22][23][24][25][26][27][28]. The study of the dynamics of the live weight of replacement heifers from different seed bulls and its conjugation by periods and with the age of the first insemination is relevant and has practical value.…”

Comparative evaluation of russian black pied and holstein cattle breeds of foreign breeding

“…The widespread, long-term use of the valuable gene pool of foreign breeding Holstein bulls led to the creation of a large array of Holstein cattle in various climatic and ecological forage zones of the country, which also differs in economically useful and biological characteristics, which is due to the breed resources of cattle breeding zone and country of origin of seed bulls involved in crossing [19][20][21]. Purebred animals of the Holstein breed were used both for crossing with bulls of the Russian Black Pied breed, and were bred among "themselves" to obtain offspring adapted to local conditions [22][23][24][25][26][27]. A comparative study of the productive qualities of the Russian Black Pied cattle and Holstein animals of foreign selection is relevant and of practical importance.…”