UDC 636.082
DOI: 10.36871/vet.zoo.bio.202309013
Authors
Natalya. I. Abramova,
Olga L. Khromova,
M. O. Selimyan,
Natalia V. Zenkova,
North-Western Research Institute of Dairy and Grassland Farming –
a separate subdivision of the Vologda Scientific Center of
the Russian Academy of Sciences, Vologda, Russia
Abstract
The current state of the herd, breeds and prospects for their development should be determined on the basis of studying the variability of the main economically useful signs and actual indicators, which allows us to identify selection and selection techniques that will ensure an increase in the productivity of animals with each new generation. The studies were carried out on a herd of Ayrshire cows on incomplete first lactation, first completed, second, third and older, taking into account the productivity of maternal ancestors. According to the results of the research, a significant variability in the milk yield of cows of the modern herd and their mothers CV=11,9–19,5 % was revealed, which allows for improving the selection of animals for the reproduction of the herd. The most effective selection was established according to the actual indicators of milk yield in mothers at the first lactation +977 kg of milk, at the highest + 456 kg of milk, with a reduction in the age of daughters in lactation. According to MJ and MDB, a weak variability of the CV=3,3–3,5 % trait was revealed in the milk of cows of the modern herd. These research results are a characteristic of the breeding situation in the herd and the possibility of its correction by directional selection and selection of animals.
Keywords
variability, correlation, heritability, breed, Ayrshire, cows, variability, selection, selection, generation, milk yield, MDJ, MDB, live weight
