Pedigree analysis is required to assess the genetic diversity and population structure of a close breeding population in order to effectively manage the breeding program and keep inbreeding under acceptable limits. Saanen x Beetal is a crossbred population of goats, reared at National Dairy Research Institute (NDRI) Karnal for the last five decades. This germplasm has been acclimated to a tropical climate and has a higher milk potential and prolificacy. Objective of this study was to elucidate the genetic diversity, population structure, and inbreeding in the flock of the Saanen x Beetal goats. The data were collected from the Animal Genetics and Breeding Division of ICAR-NDRI, Karnal for 2603 animals from the year 1971–2021. Animals born between 2014–2017 were considered as a reference cohort. Results revealed that the average generation interval was 3.44 years for the complete pedigree. The average inbreeding coefficient and the average relatedness were 4.20% and 6.87%, respectively, for the complete pedigree and 10.78% and 10.80%, for the reference population. Higher inbreeding coefficient and average relatedness in the reference cohort demonstrated impact of enclosed gene pool and demands immediate intervention for managing diversity in the closed nucleus under study. Ancestors contributing 50% of the gene pool were 8 and 3 for the complete pedigree and reference cohort, respectively, which illustrates the fact that very few ancestors were responsible for genetic diversity in the flock, which results in the decline of effective population size. Effective number of founders (fe), ancestors (fa), and founder genome equivalents (fg) were 15, 7, and 3.11, respectively. The (fe/fa) ratio in the reference population was 2.14 indicating the occurrence of the bottleneck effect in the flock. We observed that inbreeding was non-significant for all reproductive traits except for age at first service and age at first kidding. To lessen inbreeding and augment genetic diversity in the flock, the stratified breeding plan needs to be followed, where, mate sele ction would be based on relatedness. Furthermore, introduction of unrelated Saanen and Beetal crosses will help alleviate the inbreeding accumulation.

No abstract

The study of reproductive traits is crucial for improving genetic potential of goats because of their significant utility in meat production. Hence, genetic analysis was conducted for reproductive traits on Alpine × Beetal goats using animal model for first parity data. Information on 1462 reproductive records were collected over five decades from ICAR‐National Dairy Research Institute, Karnal, Haryana (1971–2021). Single‐trait and multi‐trait animal models were used for genetic analysis. Estimates of (co)variance components and genetic parameters were obtained using Gibbs Sampler for Animal Model due to non‐normal distribution of data. Six single‐trait animal models (including or excluding maternal and environmental effects) were fitted and best models were determined based on Deviance Convergence Criterion values. The prolificacy for the A × B goats for first parity data was 32%, having 68% single births, 31% twins and 1% triplets/quadruplets. The least squares mean for age at first service (AFS), age at first kidding (AFK), service period (SP), dry period (DP), gestation length (GL), kidding interval (KI), litter weight (LW), number of kids born (NKB) and number of females kids born (NFKB) in first parity were 546.15 ± 4.10 days, 679.05 ± 4.07 days, 226.51 ± 4.02 days, 67.96 ± 2.76 days, 150.74 ± 0.13 days, 362.53 ± 3.35 days, 3.99 ± 0.04 kg, 1.32 ± 0.02 and 0.64 ± 0.02, respectively. The heritability estimates obtained from best model for AFS, AFK, GL, KI, SP, and DP were 0.12 ± 0.00, 0.10 ± 0.00, 0.09 ± 0.01, 0.03 ± 0.00, 0.04 ± 0.00, and 0.05 ± 0.00, respectively. For NKB, NFKB and LW, heritability estimates were 0.16 ± 0.01, 0.03 ± 0.03, and 0.04 ± 0.00, respectively. These results imply lower heritability estimates for reproductive traits, and hence meagre scope for selection for further improvement. Maternal effects contributed significantly for traits such as GL, NKB and NFKB. Genetic correlation for number of female kids born was negative with SP and DP which is favourable. Furthermore, genetic correlation was negative for dry period and litter weight which is favourable as number of kids born and litter weight are traits of direct economic importance. Results reveal high genetic potential of this breed for meat industry owing to high prolificacy, provided consistent efforts are made for the genetic improvement of this germplasm.