Long-Lived Cows: Genealogy, Genotype, Productivity

For the first time we conducted a research on the cows of the modern population of the Holsteinized Russian Black Pied cattle of the Vologda Region, which were removed from the herd at the age of 6 calvings and more, to study the signs of duration of use and the influence of genetic and paratypic factors on these signs. The research base on, 1684 retired long-lived cows was formed on the basis of data from the information-analytical system “SELEX. Dairy cattle”. We found that the predominant number of long-lived cows (73.4) belonged to the Holstein breeding lines and 26.6% – to the lines of the Russian Black Pied cattle. Animals of the Russian Black Pied cattle lines significantly (P ≤ 0.001) surpass cows of the Holstein selection in age by 0.5 calvings, life span – by 201 days, productive life – by 130 days. At the same time, the cows of the Holstein lines have better indicators on productivity traits: on lifetime milk yield more by 455 kg of milk, on milk yield for 305 days of the first lactation – by 584 kg, maximum lactation – by 645 kg, on mass fraction of fat in milk for the first lactation – by 0.03%, maximum lactation – by 0.05% (P ≤ 0.001). The paper reveals that with increasing the degree of bloodlines on the Holstein breed decreases the value of the index of age of retirement in calving. We found that the maximum lifetime milk yield was obtained from long-lived cows with genotype 75% of the Holstein bloodlines – 53,415 kg. With increasing milking intensity of cows in the first lactation, there is a clear trend of decreasing age at calving, whole life and productive life of the cow in days, but lifetime milk yield increases. The conducted studies have shown that different approaches to breeding work in the population of the Holsteinized Russian Black Pied cattle can be used for different breeding purposes.