ISSN : 1225-2964(Print)
ISSN : 2287-3317(Online)
ISSN : 2287-3317(Online)
Annals of Animal Resource Sciences Vol.32 No.2 pp.16-22
DOI : https://doi.org/10.12718/AARS.2021.32.2.16
DOI : https://doi.org/10.12718/AARS.2021.32.2.16
Genetic Parameters of Direct and Maternal Effects for Calving Ease in Hanwoo
Abstract
This study evaluated genetic parameters of direct and maternal effects for calving ease in Hanwoo. A total of 2,102 records for calving ease were collected from 2018 to 2020 from the Hanwoo Genetic Improvement Center in Korea. The calving ease score was rated from 1 to 4 (1=unassisted delivery, 2=assisted easy calving, 3=assisted difficult calving, 4=mechanical or caesarean section) as categorical data, and the data were converted using a truncated normal distribution for linear model analysis. To evaluate the genetic parameters, the birth year-season of calving, the sex of the calf, parity, and the age of the dam at calving were considered as fixed effects, and genetic and maternal effects were considered random effects. The genetic parameters were evaluated using the program BLUPF90. The calving ease scores for male calves, first parity cows, and currently calving cows were much higher than for females, later parities, and past calving cows. The direct genetic variance (0.0164) was higher than the maternal genetic variance (0.0018), and the estimated heritabilities of the direct and maternal effects were 0.055 and 0.006, respectively. The parameters determined here should help with the genetic evaluation of calving ease in Hanwoo.