Document Type : Original Article
Authors
1
College of Agriculture, University of Baghdad, P.O. Box 19009, IRAQ.
2
International Center for Agricultural Research in the Dry Area, P.O.Box 5466, SYRIA.
3
IPA Agricultural Research Center, P.O. Box 39094, Baghdad, IRAQ.
Abstract
ABSTRACT
Animal model approach was applied to evaluate 309 does and 998 kids for milk yield and
body weight, respectively. The does belonging to four genetic groups: Local (L), Damascus (D),
Damascus X Local (DL) and Saanen X Local (SL) were evaluated over four milking seasons
(1995, 1997, 1998 and 2000). The kids were L and D purebreds and 2- and 3-way crossbreds
between Local (L), Damascus (D) and Saanen (S). All kids were born at the Agargouf Goat
Breeding Station between 1994 and 2000.
Heritability (h2) and repeatability (r) were estimated by REML after adjusting records for
the fixed effects. An Animal Model program was used to predict breeding values for animals and
their parents. Genetic and phenotypic trends of the traits studied were estimated by regression of
breeding and phenotypic values on birth years, respectively.
Genetic trends of total, test day and post weaning milk yield were 1.060 (P<0.01), –0.003
(P<0.05) and –0.105 kg/year, respectively. The phenotypic trends of the same traits were –9.275,
-0.031 and –7.303 kg/year (P<0.01), respectively. Genetic trends of body weights at 6, 12 and 18
months of age were 0.166, 0.415 and 0.310 kg/year (P<0.01), respectively, while, the phenotypic
trends were 0.161 (P<0.05), 0.751 (P<0.01) and 1.106 kg/year (P<0.01), respectively for the three
ages.
It was concluded that the breeds studied lack effective directional selection and thus a
breeding program should be activated to increase goat productivity.
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