Bangar Yogesh Chandrakant, Magotra Ankit, Yadav Abhay Singh
Department of Animal Genetics and Breeding, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar, Haryana, 125004, India.
Trop Anim Health Prod. 2020 Sep;52(5):2291-2296. doi: 10.1007/s11250-020-02248-z. Epub 2020 Mar 6.
The aim of the present study was to estimate the (co)variance components and genetic parameters for various growth traits (weight at birth (BWT) and 3 (WT3), 6 (WT6), 9 (WT9), and 12 (WT12) months of age), average daily gain (ADG1, 0-3; ADG2, 3-6; and ADG3, 6-12 months of age), and Kleiber's ratio (KR1:ADG1/WT3 and KR2:ADG2/WT6) by using records of 526 lambs of 41 sires and 186 dams in Harnali Sheep maintained at Department of Animal Genetics and Breeding, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar (Haryana), India for the period of year 2014-2019. Restricted maximum likelihood procedure (REML) was employed for estimation of covariance components and genetic parameters by considering direct effects with or without maternal effects. The estimates of direct heritability for BWT, WT3, WT6, WT9, WT12, ADG1, ADG2, ADG3, KR1, and KR2 were 0.10, 0.45, 0.32, 0.36, 0.23, 0.43, 0.02, 0.001, 0.38, and 0.02, respectively. It was observed that maternal effects had significant influence on BWT trait only, and corresponding estimate of maternal heritability was 0.16. This indicated the importance of maternal ability in Harnali sheep for initial growth performance. Moderate estimate of direct additive heritability of weaning weight (WT3) and moderate genetic correlations of it with other traits indicated that the current practice of selection at 6 months may be replaced by early selection at WT3 in order to improve the growth performance in Harnali sheep.
本研究的目的是利用印度哈里亚纳邦希萨尔市拉拉·拉杰帕特·莱伊兽医与动物科学大学动物遗传与育种系在2014年至2019年期间饲养的41头公羊和186头母羊的526只羔羊的记录，估计各种生长性状（出生体重（BWT）、3月龄（WT3）、6月龄（WT6）、9月龄（WT9）和12月龄（WT12）的体重）、平均日增重（ADG1，0至3月龄；ADG2，3至6月龄；ADG3，6至12月龄）和克莱伯比率（KR1：ADG1/WT3和KR2：ADG2/WT6）的（协）方差分量和遗传参数。采用限制最大似然法（REML），在考虑有或无母体效应的直接效应的情况下估计协方差分量和遗传参数。BWT、WT3、WT6、WT9、WT12、ADG1、ADG2、ADG3、KR1和KR2的直接遗传力估计值分别为0.10、0.45、0.32、0.36、0.23、0.43、0.02、0.001、0.38和0.02。观察到母体效应仅对BWT性状有显著影响，母体遗传力的相应估计值为0.16。这表明母体能力对哈纳利羊初始生长性能的重要性。断奶体重（WT3）的直接加性遗传力估计值适中，且与其他性状的遗传相关性适中，这表明为了提高哈纳利羊的生长性能，目前6月龄的选择做法可能会被WT3时的早期选择所取代。
