Estimation of genetic and phenotypic parameters for growth traits of Egyptian buffaloes using mtdfreml program
Abstract: Data on growth traits for pre and post weaning on 1003 Egyptian buffalo calves (527 males and 476 females) progeny of 214 dams mating by 70 sires during the period from 2001 to 2012 at Mahallet Mouse Farm was used in this study. Restricted Maximum Likelihood analysis method was used with animal model to estimate covariance components for weight at birth (WB), weight at weaning (WW), weight at 12 month age (W12) and weight at 18 month age (W18). Model included month and year of birth, parity (birth sequence), farm and sex of calf as fixed effects. Random effects were animal, direct and maternal genetic effect, maternal permanent environmental effect and residual effect.
Overall means and standard errors for WB, WW, W12 and W18 were 36.30±6.19, 91.31±10.27, 212.32±25.37 and 301.59±51.03 kg, respectively. Direct heritability (h2 a) for WB, WW, W12 and W18 were 0.30, 0.32, 0.40 and 0.52, respectively. Corresponding maternal heritability (h2 m) were 0.38, 0.26, 0.18 and 0.09, respectively.
Estimates of maternal permanent environmental variance as a proportion of phenotypic variance were 0.23, 0.18, 0.18 and 0.11 for WB, WW, W12 and W18, respectively. Antagonism was observed between additive direct and maternal genetic effects and it were negative in all traits investigated, ranging from -0.71 to -0.28. Genetic and phenotypic correlations between all studied traits were positive and ranged from 0.38 to 0.80. The positive maternal genetic correlations (0.54 to 0.92) of birth weight with later weights indicateted that maternal influences on the later weights are partly originating from the prenatal period. The present results show that the direct genetic heritabilities and residual effects increases with aged increased. Vice-versa in the direct maternal and permanent effects were decreases' as, aged increased. Our data results suggest that all growth traits and mainly W12 and W18, have clear potential for yield improvement through direct genetic selection.
Keywords: Growth traits, Egyptian buffalo calves, maternal effect, direct effect, direct heritability, maternal heritability and direct-maternal genetic correlations.
Publication year 2014
Availability location معهد بحوث الانتاج الحيوانى- شارع نادى- الصيد- دقى- جيزة
Availability number
Organization Name
Country Egypt
City كفر الشيخ
serial title Journal of Agriculture Research Kafr EI-Sheikh University
ISSN 1110-032x
Volume 40 . 4
Author(s) from ARC
Agris Categories Animal husbandry
AGROVOC
TERMS		 African buffaloes. Birth weight. Calves. Genetic correlation. Genetic covariance. Genetic parameters. Growth. Heritability. Mothers. Weaning weight.
Proposed Agrovoc direct effect;
Publication Type Journal
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