Estimation of genetic parameters for early reproduction traits in Beetal goat

Summary The evaluation of early reproduction traits in Beetal goat was performed for possible effects of genetic and non-genetic factors on litter size at birth (LSB), litter size at weaning (LSW), litter weight at birth (LWB), litter weight at weaning (LWW) and age at first kidding (AFK). The data records consisted of information of pedigree and targeted traits pertained to 223 does born to 25 sires and 122 dams between the years 2004 to 2019. A general linear model was used for assessment of non-genetic factors such as period of birth, type of birth and dam’s weight at kidding on studied traits. Genetic evaluation of targeted traits was done to estimate variance components and genetic parameters under dyadic mixed modelling. The estimates of least-square means for LSB, LSW, LWB, LWW and AFK were observed as 1.27 ± 0.03, 1.25 ± 0.03, 3.24 ± 0.07 kg, 13.08 ± 0.30 kg and 27.56 ± 0.58 months, respectively. Only the period of birth showed significant (P < 0.05) effects for targeted traits in this study. The estimates of direct heritability for LSB, LSW, LWB, LWW and AFK were low in magnitude as 0.08, 0.03, 0.10, 0.03 and 0.06, respectively. The moderate to high genetic and phenotypic correlations among litter traits indicate simultaneous improvement for these traits. It was concluded that low ranged direct heritability estimates for targeted traits indicated modest scope for genetic improvement of reproductive efficiency in Beetal goat through selection and, therefore, adoption of improved managerial practices is necessary to improve reproductive efficiency of Beetal goat.

Molecular investigations on the Rajanpuri strain of Beetal goat breed of Pakistan by complete mtDNA displacement region and microsatellite markers

The mitochondrial DNA sequences of DNA-D loops (mtDNA) from 105 individuals (11 Beetal goat Rajanpuri strains and 94 sequences extracted from GenBank) from 19 geographically and phenotypically defined domestic goat breeds in Pakistan were analysed in this experiment. In this study, we examined variability and molecular phylogeny of breeds. A total of 81 haplotypes were observed in 105 individuals, with a haplotype diversity of 0.984±0.006 and nucleotide diversity of 0.03953±0.00843. Phylogenetic analysis based on the mtDNA hyper variable segment (HVI) of the control region (481 bp), showed four mtDNA haplogroups (A, B1, C, and D) identified in Pakistani domestic goats, in which haplogroup A (84.11%) was dominant and widely distributed among all investigated breeds. The study revealed that all Rajanpuri strain haplotypes belonged to haplogroup A. The Rajanpuri is a rare local strain of Beetal goat breed located in western Punjab province of Pakistan. The results of genetic diversity based on 11 microsatellite loci revealed allelic diversity (3.6363) and high genetic diversity (0.8342) in the examined Rajanpuri goat breeds. The analysis for signature bottleneck events, using three models, revealed significant deviation of Rajanpuri goats from mutation drift equilibrium. The qualitative test of mode shift analysis also supported the results obtained under three models, indicating the presence of a recent genetic bottleneck in the Rajanpuri strain. This study provides the first information on the mtDNA architecture, genetic diversity and bottleneck analysis, which will be useful in the conservation and management of the highly valued Rajanpuri goat.