Estimates of direct and maternal effects for early growth traits of zaraibi goats
Abstract: Records of growth traits of 10,374 Zaraibi kids were used to estimate variance-covariance component and genetic parameters. Traits analyzed were birth weight (BW), weaning weight (WW), 180-d weight (W 180), pre weaning daily gain (PRWG) and post-weaning daily gain (PSWG). Variance-covariance components were estimated using restricted maximum likelihood with an animal model. Four different animal models were fitted in order to determine the most appropriate model for each trait. In addition to the additive direct effect of the animal, model 2 included the additive maternal effect while model 3 included the permanent maternal effect. The fourth model included the additive direct effect of the animal, the additive maternal and the permanent maternal environmental effects. Introducing the additive maternal effect to model 2 reduced the estimate of additive heritability by (10, 7, 9, 0 and 2%) for BW, PRWG, WW, PSWG and W180, respectively. When permanent maternal effect was replaced with the additive maternal in model 3, additive direct effect was reduced by 16, 8, 11, 2 and 1% for BW, PRWG, WW, PSWG and W180, respectively. When additive and permanent maternal effects were added to the direct additive in model 4, direct heritability was reduced by 9, 7, 9, 0 and 2% for BW, PRWG, WW, PSWG and W180, respectively. The correlation between direct and maternal genetic effects was negative for BW, PRWG and WW and positive for PSWG and W180. Maternal effects (additive and permanent) should be accounted when estimating genetic parameters for growth traits.
Keywords: growth traits, heritability, variance component, maternal effect, Zaraibi goats
Publication year 2013
Pages 7-14
Availability location معهد بحوث الانتاج الحيواني- شارع نادي الصيد- الدقي- جيزة
Availability number
Organization Name
Country Egypt
serial title Egyptian Journal of Sheep and Goat Sciences
ISSN 2090-0368
Volume 8 . 1
Author(s) from ARC
Agris Categories Animal husbandry
AGROVOC
TERMS		 Genetic parameters. Goats. Growth factors. Growth rate. Heritability. Mothers.
Proposed Agrovoc growth traits;variance component;Zaraibi goats;
Publication Type Journal
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