الفهرس | Only 14 pages are availabe for public view |
Abstract The aim of the present study was to obtain the main effects such as birth sex, birth year, birth season, birth type and the interaction between year and season for some growth traits (body weight at birth, 30, 60, weaning, 120 and 180 day) in Zaraibi goats. Estimate the genetic and phenotypic parameters for the same traits by fitting different models including direct, maternal and maternal permanent environmental effects. Estimate the genetic, maternal and phenotypic trends for studied traits. The present results indicated that all fixes factors had significant effects on all body weights except the effect of birth season on live body weight at 30 day , 60 day and weaning weight. Direct heritability estimates ranged from 0.23 to 0.43, 0.28 to 0.41, 0.20 to 0.31, 0.17 to 0.34, 0.15 to 0.32 and 0.24 to 0.28 for body weight at birth, 30, 60, weaning, 120 and 180 day, respectively. Corresponding maternal heritability for mentioned traits tends to decline from (0.21) for birth weight to (0.07) for body weight at 180 day. Annual direct genetic trends for body weight at birth, 30, 60, weaning, 120 and 180 day were 6.22, 16.64, 7.731, 33.501, 31.986 and 72.419 g/year, respectively. Corresponding maternal genetic trends were -5.200, 22.51, 15.215, 24.59, -24.05 and -23.805 g/year, respectively. Phenotypic trends for growth traits by year of calving were 3.05, 39.74, 27.75, 55.99, 8.24 and 59.82 g/year, while the maternal permanent environmental trends were 0.024, 0.1012, 0.1149, 0.1435, 0.2261 and 0.1464 g/year for mentioned traits respectively. |