Ayham Bakri
General Commission for Scientific Agricultural Research-
Ura Research Station
Faculty of Agriculture, Damascus University,
2010

Abstract

The study was carried out on records of Jabaly and Shami breeds of goats and their crossing at Ura research station to study their productive and reproductive performance. Records of  the year 1987-2007 were analyzed to study the effect of some genetic and non-genetic factors, such as breed group, year of birth, season of birth, type of birth, parity, sex of kids and the interaction on kid performance and milk production.
Studies traits were included: birth weight, weaning weight, milk yield and lactation period. The results obtained from the analysis of these records showed that:
-*The genotype significantly affected milk production. Type of birth, year of birth and parity were highly significant on milk production. the interaction between type of birth and parity also affected milk production. The interaction between breed groups and type of birth had insignificance on milk production. The least squares means of milk production. 50% Jabaly was the first in terms of milk production. For milk production the order of genotypes as follows: 75% Jabaly, (G75), 75% Shami, (SG50), G, (GS50).
-*Heritability of milk production on Jabaly goats was 0.39±0.11.
-*The genotype and type of birth and sex affected highly significant birth weight. While parity was insignificant. The interaction between genotypes and sex, the interaction between sex and type of birth, and the interaction between sex and parity had insignificant effect on birth weight. While the interaction between type of birth and parity was significant on birth weight, and the interaction between genotypes and type of birth highly affected birth weight.
-*The difference between breed groups, type of birth, sex and parity were highly significant on weaning weight. the interaction between breed groups and sex had significance on weaning weight, and the interaction between sex and type of birth and the interaction between sex and parity had an insignificant effect on weaning weight. While the interaction between breed groups and the type of birth had a significant effect on weaning weight.
-*The difference between genotypes and parity had insignificant effect on lactation period, while the type of birth and year of birth had significant effect on lactation period. The interaction between type of birth and parity was insignificant on lactation period, and the interaction between breed groups and type of birth had significant on lactation period.
-*The value of change in milk production for all crossing generations in comparison with Jabaly goats was 33.40, 17.88, 3.83 for F1, F2, F3, respectively. So F1 higher than Jabaly goats at percentage 15.09%, while F3 was higher than Jabaly goats at 1.73%, and F2 at 8.08%.
-*The value of change in birth weight for all crossing generations as compared with Jabaly goats was 0.04, 0.14, 0.20 for F1, F2, F3, respectively. So, F2 was higher than Jabaly goats at 4.33%, while F1 at 23%, and F3 at 5.88%.
-*The value of change in weaning weight for all crossing generations as compared with Jabaly goats was -2.27, 0.19 and 0.40 for F1, F2 and F3, respectively. So F2 was higher than Jabaly goats at 1.55%, while F1 decreased by 19.12%, and F3 was higher than Jabaly goats at 3.36%.
-*The value of change in lactation period for all crossing generations in comparison with Jabaly goats was -4.38, -1.31 and 1.53 for F1, F2 and F3, respectively.
-*The least squares means of milk yield and lactation period were 209.89 kg, 177.37 day, respectively.
-*The individual and maternal and the crossing maternal and the recombination had significant effect on milk production.
-*The estimates of genetic variability in milk production showed negative individual crossing (gI) so breed groups were better than Jabaly goats in milk production. There were negative values for crossing maternal (hm), so breed groups were less than mother husbandry for kids, and there were negative values for maternal crossing (gm), so breed groups mother goats were better than Jabaly mother goats on milk production. There was a negative value for crossing individual crossing (hI), so there was insignificance for crossing individual (hI) in milk production. In breed groups the type crossing (S.GS) 75% Shami, (G. SG) 75% Jabaly, are the best by crossing process. So, we can maintain genotype S.GS, G. SG by intersex mating.