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Genetic determination of individual birth weight, litter weight and litter size in Mukota pigs |
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| Authors: | M. Chimonyo K. Dzama E. Bhebhe |
| Affiliation: | aDepartment of Livestock and Pasture Science, Faculty of Science and Agriculture, University of Fort Hare, P. Bag X1314, Alice 5700, South Africa bDepartment of Animal Sciences, Stellenbosch University, P. Bag X1, Matieland 7602, South Africa cDepartment of Paraclinical Veterinary Studies, University of Zimbabwe, P. O. Box MP 167, Mount Pleasant, Harare, Zimbabwe |
| Abstract: | Genetic parameters for individual birth weight (IBWT), total number of pigs born (NBT), number of pigs born alive (NBA), number of pigs born dead (NBD) and litter weight at birth (LBWT) were estimated using 1961 Mukota pigs kept at the University of Zimbabwe Farm, Harare, Zimbabwe. Variance components were estimated for IBWT based on a direct-maternal genetic effects model. The genetic relationships among NBT, NBA, NBD and LBWT were assessed using a multi-trait direct effects model. For LBWT, the direct, maternal and common environmental litter proportions on the phenotypic variance were 0.090, 0.033 and 0.009, respectively. After adjustment of IBWT for NBA, phenotypic fractions were 0.091, 0.034 and 0.011 for direct, maternal and litter effects. The correlation between the direct and maternal genetic effects of IBWT was − 0.354 and − 0.295, with and without adjustment for NBT. Heritabilities for NBT, NBA, NBD and LBWT were 0.020, 0.030, 0.088 and 0.196, respectively. Differences in the maternal heritability and the heritability for LBWT, a trait of the dam, are different due to accumulation of observations per litter. Maternal genetic effects are, therefore, of less importance than in highly selected European breeds. |
| Keywords: | Heritability Maternal effects Birth weight Litter size Mukota pigs |
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