Kamel Fattal*(1) and Khaled Elnajjar(2)
(1). Breeding Shami Goats Research Station, Agricultural Research Center in Aleppo, General commission for Scientific Agricultural Research (GCSAR), Aleppo, Syria.
(2). Animal Wealth Research Administration, GCSAR, Damascus, Syria.
(*Corresponding auathor: Dr. Kamel Fattal,. E-Mail: kamel1960@gmail.com).
Received: 23/04/ 2015 Accepted: 16/09/ 2015
Abstract
This study was conducted to study the productivity performance of Shami goats for milk production, and litter size weight at birth and weaning. Also to estimate the litter size at birth and weaning, and age, weight of goat when insemination. And determine the effect of some genetic factors (parents) and non-genetic (year of birth, parity, kids sex, age and weight at insemination) of the studied traits. And estimate some genetic parameters (heritability and genetic correlations) of the studied traits. Data was collected from the records at Hememah Research Station of Al Shami Goat Improvement, General Commission for Scientific Agricultural Research (GCSAR), Aleppo/Syria. during 2001 to 2010. Statistical analysis was made of the studied traits to figure out the genetic and environmental effects on it using SAS program. Duncan test was used to compare the means of the factors affecting the studied traits, and also the animal model was used to estimate the genetic parameters. Milk production, and litter size weight at birth and weaning were 424.46±67.24, 8.42±0.53 and 19.49±2.94 Kg, respectively. The litter size at birth and weaning, and age and weight at first insemination were 2.98 ± 0.04, 2.20 ± 0.19, and 46.73±0.57 kg, and 19.24±0.26/ month, respectively. It was found that the parents has a highly significant effect on the production of milk and insignificant effect on the litter size weight at birth and weaning. The effects of year of birth and parity were highly significant on all traits (milk production and litter size weight at birth and weaning). The impact of gender on the production of milk was not significant, while highly significant on birth litter size weight at birth and weaning. The linear model of the mother goat birth and its age at insemination any significant effects on the studied traits. The weight of goat at insemination had highly significant effect on milk production and the litter size weight at birth, while there were no significant differences in the weight of the goat at insemination on litter size weight at weaning. Estimates of heritability for milk production, and litter size weight at birth and weaning were 0.14, 0.08, 0.20, respectively. The values of genetic correlations between milk production, and the litter size weight at birth and weaning were -0.17 and -0.01, respectively. While the genetic correlation between the litter size weight at birth and at weaning was 0.09. The study concluded that, the genetic correlation between milk production, and the litter size weight at birth and weaning was negative. This indicates that the increase in litter size weight at birth and weaning will lead to stress the body of the goat and this negatively affects the production of milk, although the study concluded a positive genetic relationship between litter size weight at birth and at weaning. According to that, litter size weight at weaning will considered as a selection breeding criteria, because it achieved the highest genetic variation compared with milk production and the litter size weight at birth. During selection it is very important to take into consideration the differentiation between the parents to increase the production of milk of female’s goats. The environmental conditions should be taken into account because of they affect all traits, especially goats weight at insemination, because of its big role in the values of traits.
Key words: Genetic parameters, Shami goats, Milk production, Litter size at birth and weaning, Syria.
Full paper in Arabic:التقويم الوراثي لصفات إنتاج الحليب وكتلة البطن عند الميلاد والفطام في الماعز الشامي
