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

Abstract

This study aimed to evaluate the genetic potential of the Jamunapari goat and formulate a selection strategy for improving lactation traits. The data set included 4049 phenotypic records for across parity milk yield at 90days (MY90), 140days (MY140), total milk yield (TMY), and lactation length (LL) obtained from the progeny of 83 sires and 1643 dams between the period 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 across parity 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 influence (c2) was significant in milk yield attributes, whereas direct maternal genetic effects were absent. As the early selection criteria based on first parity records are essential, we analyzed the data for the first parity separately and obtained moderate h2 estimates, viz., 0.26 ± 0.05, 0.16 ± 0.06, and 0.25 ± 0.06 for MY90, MY140, and TMY, respectively. These estimates augur further 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 first parity MY90 as a single trait selection criterion for genetic improvement of all lactation traits in Jamunapari goat.