Devising a selection strategy for the Jamunapari goat for improving lactation performance

Abstract

This study aims to evaluate the genetic potential of the Jamunapari goat and formulate a new selection strategy for improving the lactation traits. The data set included 4049 phenotypic records for lifetime milk yield at 90 days (MY90) and 140 days (MY140), total milk yield (TMY), and lactation length (LL) obtained from the progeny of 83 sires and 1643 dams between 1990 and 2019. Animal model employing average information restricted maximum likelihood (AIREML) was used to estimate genetic parameters for milk yield traits and LL. The direct additive heritability estimates for lifetime lactation traits, that used repeatability model were 0.10 ± 0.03, 0.08 ± 0.03 and 0.12 ± 0.02 for MY90, MY140 and TMY, respectively, while it was low for LL (0.06 ± 0.02). The repeatability estimates were moderate ranging from 0.17 to 0.22 for milk yield traits and LL, indicating persistent performance over the parities. Animal permanent environment in uence (c 2 ) was signi cant in milk yield attributes, whereas additive maternal genetic effects were absent. As the early selection criteria based on rst parity records is essential, we analysed the data for the rst parity separately and obtained moderate h 2 estimates viz. 0.26 ± 0.05, 0.26 ± 0.06 and 0.25 ± 0.06 for MY90, MY140 and TMY, respectively. These estimates augurs further positive scope of selection in Jamunapari goats for higher milk yield. High and positive genetic correlation of MY90 with MY140 (0.97 ± 0.01) and TMY (0.91 ± 0.05) revealed the scope of using MY90 as the selection criterion.Based on these results, we recommend use of MY90 as a single trait selection criterion for genetic improvement of all lactation traits in Jamunapari goat.

Optimizing selection strategy for enhancing reproduction efficiency in Indian crossbred goats using milk productivity as a selection criterion

“…These maternal heritability estimates were influenced by a large negative estimate of covariance between additive genetic and maternal effects. Similar findings regarding the significance of the maternal component have been reported in previous studies, such as in the estimation of total lactation yield in Jamunapari goats (Rout et al, 2017) and lactation length (Dige et al, 2022).…”

“…Higher heritability estimates as compared to the present study for lactation traits have been reported across several breeds ranging from 0.22 to 0.30 (Boichard et al, 1989;Dige et al, 2022;Rout et al, 2017;Singh et al, 2021;Valencia et al, 2006). These findings underscore the variability in heritability estimates for these traits, which can be influenced by factors such as breed, selection pressure and the genetic makeup of the studied populations.…”

“…The positive and relatively high genetic correlation among three traits (except DIM) indicates that selection for one trait can lead to correlated responses in others. Comparable findings for correlation among these traits have been reported in different breeds of goats (Dige et al, 2022;Prajapati & Mandal, 2017;Roy & Ajoy, 2010;Yadav et al, 2004). Yadav et al (2004) found strong phenotypic correlations, with 90-day milk yield (90MY) exhibiting a significant positive relationship with 150MY (0.91), total milk yield (TMY) (0.88), and parity yield (PY) (0.75).…”

“…Dige et al. (2022) confirmed high genetic correlations, such as 0.97 between 90MY and 140MY and 0.91 between 90MY and TMY. However, in contrast to our finding, Singh et al.…”

“…Various workers reported the average 150DMY (kg) in different dairy goat breeds such as Jakhrana, Jamunapri, Marwari, Kutchi and Sirohi ranged from 83.52 to 113 (Dige et al., 2022; Dudhe et al., 2016; Rai, Khan, & Yadav, 2001; Rai, Tiwari, & Khan, 2001; Yadav et al., 2004). Even the estimates for DIM and TMY (236.42 ± 3.04 days, 269.62 ± 4.52 kg) in the current study were significantly higher than that of other Indian goat breeds.…”