Reproductive qualities of daughters of Ayrshire bulls-carriers of the fertility haplotype AH1

UDC 636.22 / 28.082
DOI: 10.36871/vet.zoo.bio.202112010

Authors

Olga V. Tulinova,
Russian Research Institute of Farm Animal Genetics and Breeding – Branch of the L.K. Ernst Federal Research Center for Animal Husbandry, St. Petersburg, Pushkin, Russia

Abstract

An analysis of the reproductive qualities of the retired cows of Ayrshire breed, first calving in the period 2009–2016, was carried out, of which 7278 heads are daughters of bulls tested for carriage of the AH1 fertility haplotype: carriers (AH1C) – 16 heads and free (AH1F) – 41 heads at the number of offspring is 1391 and 5887 heads, respectively. It was found that the relative number of cows in the two analyzed groups did not differ – the difference did not exceed 1,0% (from –0,9 to +0,8%). It was found that abortions in the AH1C group are 0,13% lower, and stillbirths by 0,18% higher. The difference between the bulls and heifers born (in favor of bulls) is greater in the first group of animals (9,38 versus 7,64%). Data analysis showed that the age of the 0,4st insemination and calving was 0,05 months (p≤1) significantly later in the offspring of AH0,05C bulls. The number of insemination after the 0,04st calving in this group of animals is also significantly higher (p≤0,05) by 6 doses. Significant differences (p≤3) were revealed in the duration of intercalving and dry period for the highest lactation, which were 10 and 21 days, but on average for all completed lactations, a significant difference was not established for all studied characteristics. For the last completed lactation, there was a large difference in the number of milk days and days of pregnancy for incomplete lactation (–16 and –1 days, respectively). The term of productive use is 1 days longer in the group of descendants of bulls АНXNUMXС, bu t the difference is not significant. Productive use is XNUMX days longer in the group of bulls АНXNUMXС, but the difference is not significant. It can be concluded that the use of AHXNUMXC bulls for cows can be allowed if the economic effect of productivity covers the costs for a later period of the start of productive use (the cost of raising a heifer to the XNUMXst calving), from the loss of calves (stillbirth) and due to a decrease in the number of heifers for herd reproduction and pedigree sale.

Keywords

ayrshire breed, AH1 fertility haplotype, productive use, reasons for retirement, stillborn, abortion, number of insemination, service period.