Estimates of Parameters for Genetic Relationship between Reproductive Performances and Body Condition Score of Hanwoo Cows

S B Choi,J W Lee,Y H Choy,N S Kim,K J Na

doi:10.5713/ajas.2005.909

Abstract

This study was conducted to estimate phenotypic and genetic parameters of body condition score (BCS) and reproductive traits in Hanwoo cows. DFREML procedures were applied to obtain variance-covariance components and heritability estimates with single or two-trait models. Estimates of phenotypic correlations of BCS at service with BCS at calving was 0.16 and 0.26 with calving interval, 0.08 with gestation length, and 0.06 with number of services per conception, respectively. Estimates of phenotypic correlation of BCS at calving was 0.10 with calving interval, 0.13 with gestation length, and 0.10 with number of services per conception, respectively. Estimates of phenotypic correlation were low and negative, -0.11 between calving interval and gestation length and -0.13 between gestation length and number of services per conception. Estimates of direct genetic correlation were -0.06, between BCS at service and BCS at calving, 0.37 between BCS at service and BCS at weaning, and -0.18 between BCS at calving and BCS at weaning. Estimates of direct genetic correlation of days from calving to the 1st service were 0.17 with number of services per conception and -0.21 with BCS at service. Estimates of direct genetic correlation for BCS at calving were -0.02 with number of services per conception and -0.08 with BCS at service. Estimates of direct genetic correlation for BCS at weaning were 0.02 with number of services per conception and -0.07 with BCS at service. Estimates of direct heritability from single trait analyses were 0.13 for BCS at service, 0.20 for BCS at calving, 0.02 for BCS at weaning, and 0.20 for number of service per conception, respectively. Estimates of direct heritability were 0.20 for birth weight and 0.10 for weaning weight. (Asian-Aust. J. Anim. Sci. 2005. Vol 18, No. 7 : 909-914)

Highlights

Body condition of cows around calving season is Arango et al (2002) suggested that body condition closely related with efficiency of cows’ reproduction such score might be useful for evaluating cow weight at constant as recurrence of heat, milking, days open, calving interval, fatness
Over-conditioned cows, The objective of this study was to estimate genetic on the other hand, required more times of services for parameters of and between days from calving to first conception and obese cows often failed maintaining normal service, number of services per conception, calves’ birth reproductive cycle (Rasby and Gosey, 1998)
Body and weaning weights and BCS of cows and heifers at condition of immature heifers is especially important for services, at calving or at weaning which might vary with their normal body growth and for their successful reproductive and physiological status, season and nutrition

Summary

Introduction

Body condition of cows around calving season is Arango et al (2002) suggested that body condition closely related with efficiency of cows’ reproduction such score might be useful for evaluating cow weight at constant as recurrence of heat, milking, days open, calving interval, fatness. Body and weaning weights and BCS of cows and heifers at condition of immature heifers is especially important for services, at calving or at weaning which might vary with their normal body growth and for their successful reproductive and physiological status, season and nutrition. Reproduction in the future as well as stayability in breeding We expect that results from this study would be directly herd. Female reproductive traits such as age at first service, applied for better reproductive and feeding management of age at first calving, calving interval, number of services per cows and heifers. Conception or days from calving to first service are lowly heritable and, are affected greatly by environments

Objectives

Methods

Results