DOI: 10.36871/vet.zoo.bio.202107006
UDC 636.2.084
Authors
N. A. Popov
Doctor of Biological Sciences, Professor, Chief Scientist,
All-Russia Research Institute of Animal Husbandry
named after Academy Member L. K. Ernst,
Dubrovitsy, Russian Federation
Abstract
The aspects of reasonableness in developing the line breeding strategy at the current status stage
of dairy breeds and its significance as a factor for genetic variability have been reported. The
value for milk production of the first-calf heifers within the line-bred pedigree Red-and-White cattle
is estimated. Particular characteristics of the progeny produced from mating in the inbred and
crossbred lines are recorded. The lower trait variability of traits was found with selecting within the crossbred lines than that in the inbred lines. Thus, the variables for the milk yield, the mass fraction
of fat (MFF) in milk, and the mass fraction of protein (MFP) were less by 4–13% of the mean
square deviation, 11,3–20,6%, and 14,3%, respectively.
Livestock breed differentiation between the breeding lines was previously executed with the artificial
elements of isolation systems. At present, the breeds widely distributed in the Russian Federation
are usually “improved” with the use of Holsteins. Therefore, their genealogy and breeding
structures depend on the foreign gene pool. Selection strategies for the improvement of milkability
traits were implemented along with selection of bull sires capable of improving the conformation. In
addition, certain herd bulls were used repeatadly. The variables for genetic values for milkability
traits, which changed over time, were monitored. The herd milk production within the lines over
a generation increased by 624–786 kg milk (P<0,001), while the MFF deacresed by 0,18–0,25%
(P<0,001). Depending on the types of breeding, the differences in the milk yields and the MFF of
the first-calf heifers between the lines comprised 178–444 kg (P<0,001) and +0,01%, respectively.
However, a statistically significant difference between the lines was recorded only for the MFP,
which comprised 0,03% (P<0,001).
Keywords
line breeding, milk production, variability, breeding value, bull sires, breeding program, trait value
