MATERNAL COMPONENTS AS RELATED TO DIRECT COMPONENTS FOR SOME GROWTH TRAITS OF FRIESIAN CALVES IN EGYPT

Records of growth traits from birth to weaning on 1713 Friesian calves (813
males and 900 temales) daughters of 703 dams and 93 sires during the period from
1982 to 2001 at Sakha and EI-Karada farms were used in the analysis. (Co)variance
components were estimated with REML using an animal model that indu ed the fixed
effects of month and year of birth, sex, farm and birth sequence. Random effects were
animal, direct and maternal genetic effects, matemal permanent environ ental effect
and random effect. Weight of dam at calving was included in the model as a covariate.
Direct and maternal genetic effects and other parameters for birth weight (8W),
weaning weight 0N'N) and daily gain (DG) from birth to weaning were estimated.
Overall means and standard deviations for BW, WN and DG were 30.8 ± 5.1 kg, 96.5
± 10.2 kg and 547 ± 89 g/day, respectively. Direct heritability of the me tloned traits
was 0.32, 0.34 and 0.37, respectively. Heritabilities of maternal effects of BW (O.H),
VVW (0.14) and DG (0.09) were smaller than direct heritabilities. Estimates of
permanent environmental variance as a proportion of phenotypic variance were 0.12,
0.08 and 0.04 for 8W, WN and DG, respectively. Estimates of direct-mat~rnal genetic
correlations in all traits studied were negative ranging from -0.59 to -0.02. Genetic and
phenotypic correlations between BW and DG were small and negative, -0.14 and-
0.22, respectively, while genetic and phenotypic correlations between WN and DG
                were high and positive, 0.84 -and 0.93, respectively.