Affiliation:
1. Department of Animal Genetics and Breeding Lala Lajpat Rai University of Veterinary and Animal Sciences (AGB) Hisar Haryana India
Abstract
AbstractThe research utilized data from 662 Murrah buffaloes meticulously recorded over 24 years (1996–2019) from historical pedigree sheets maintained at the buffalo farm of the Department of Livestock Production and Management (LPM) at Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar. A series of six univariate animal models were employed to calculate estimates of (co)variance components and heritability for first lactation reproduction traits. Among these models, Model 2 was identified as the best fit for age at first calving (AFC) and calving interval (CI), while Model 1 proved optimal for service period (SP) and conception rate (CR). The heritability estimates for AFC, SP, CR and CI across the models were ranged between 0.11 and 0.32, 0.01 and 0.03, 0.05 and 0.06, and 0.01 and 0.06, respectively. Maternal effects (m2) were observed in AFC and CI, ranging from 0.10 to 0.20 and 0.01 to 0.03, respectively. Across all three traits, there was a consistent negative genetic correlation (−0.75 to −0.92) between direct additive and maternal effects. The breeding values for AFC, SP, CR and CI varied within specific ranges from −32.85 to 44.33 days, −15.61 to 28.42 days, −7.41 to 6.48% and −20.64 to 35.79 days, respectively. Significantly, Spearman's rank correlation analysis revealed highly significant relationships (p < .01) between the breeding values of different models, indicating strong and consistent associations within these traits. These findings underscore the stable and reliable connections observed within the breeding values for these essential reproductive traits across the various models used in the study. The majority of reproductive traits showed favourable negative trends, indicating a positive outcome. A decrease in AFC, SP and CI suggests an extended economic life for the animals. Additionally, the upward trends in CR reflect positive indications of effective management practices and skilled operational procedures.
Subject
Endocrinology,Animal Science and Zoology,Biotechnology
Reference52 articles.
1. Relationships between reproductive traits of heifers and cows and yield traits for Holsteins in Japan
2. Estimation of genetic parameters of the productive and reproductive traits in Ethiopian Holstein
using multi-trait models
3. Genetic and phenotypic variation of some reproductive traits in Egyptian buffalo
4. Heritability, genetic and phenotypic correlations of milk production and reproduction traits of Ethiopian Boran cattle with different levels of Holstein Friesian inheritance;Birhanu T.;Journal of Reproduction and Infertility,2015
5. Genetic analysis of conception rate in French Holstein cattle;Boichard D.;Acta Agriculturae Scandinavica Section A Animal Science,1994