Genetic and phenotypic parameters of body weight in west African dwarf goat and Djallonke sheep. In Genetic improvement of livestock in Tsetse infested areas in west Africa
The International Trypanotolerance Centre’s small ruminant breeding meat production and the trypanotolerance of the animals (sheep and goat) To achieve that goal, selection was based on estimated breeding values for daily weight gain from 4 to 12 months of age measured on trypanotolerance challenge. The purpose of this study was to estimate genetic parameters for growth traits and to evaluate genetic trends in west African Dwarf goat and Djallonke sheep for West African Dwarf Goat and Djallonke sheep included birth weight (BW), weaning weight (W120), yearling weight (W360), Pre-weaning (GRO-4) and post-weaning (GR4-12) growth rate. The data were analysed using an animal model that accounted for fixed effects of sex, year of birth, season of birth, parity of the dam, type of birth and the interaction year by season of birth. Estimates of heritability for BW, W120, W360, GR0-4 and GR4-12 were 0.5, 0.43, 0.32 and 0.11for goats and 0.39, 0.54, 0.21, 0.54 and 0.23 for sheep, respectively. The genetic correlation between BW and W120 was high for goats (0.74) and moderate for sheep (0.47). Genetic correlations between W120 and GR4-12 were high (0.92) for goats and moderate (0.49) for sheep. Between GR0-4 and BW the correlation was positive but low for sheep (0.26) and moderate for goats (0.60). Positive trends were found in mean estimated breeding values for animals born in the period 1995-2002, which demonstrated the effectiveness of the implemented breeding programs.
| Main Authors: | , , , , |
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| Format: | Book Chapter biblioteca |
| Language: | English |
| Published: |
2006
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| Subjects: | goats, sheep, genetics, livestock, phenotypes, body weight, dwarfs, heritability, growth, ghambia, |
| Online Access: | https://hdl.handle.net/10568/70950 |
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| Summary: | The International Trypanotolerance Centre’s small ruminant breeding meat production and the trypanotolerance of the animals (sheep and goat) To achieve that goal, selection was based on estimated breeding values for daily weight gain from 4 to 12 months of age measured on trypanotolerance challenge. The purpose of this study was to estimate genetic parameters for growth traits and to evaluate genetic trends in west African Dwarf goat and Djallonke sheep for West African Dwarf Goat and Djallonke sheep included birth weight (BW), weaning weight (W120), yearling weight (W360), Pre-weaning (GRO-4) and post-weaning (GR4-12) growth rate. The data were analysed using an animal model that accounted for fixed effects of sex, year of birth, season of birth, parity of the dam, type of birth and the interaction year by season of birth. Estimates of heritability for BW, W120, W360, GR0-4 and GR4-12 were 0.5, 0.43, 0.32 and 0.11for goats and 0.39, 0.54, 0.21, 0.54 and 0.23 for sheep, respectively. The genetic correlation between BW and W120 was high for goats (0.74) and moderate for sheep (0.47). Genetic correlations between W120 and GR4-12 were high (0.92) for goats and moderate (0.49) for sheep. Between GR0-4 and BW the correlation was positive but low for sheep (0.26) and moderate for goats (0.60). Positive trends were found in mean estimated breeding values for animals born in the period 1995-2002, which demonstrated the effectiveness of the implemented breeding programs. |
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