Oussama Mohammad Al sheblak
General Commission for Scientific Agricultural Research
Animal wealth Research Administration
Faculty of Agriculture, Damascus University
This study was carried out at AL. yadoda research station ,Daraa center .GCSAR, to analyze weight data of local cattle (Akshi,Shami,Golani)-101 ahead of calves were weighted on several ages (birth, one and half month, three month, six month, twelve month, eighteen month). The general liner model was used to characterize the growth curve by using Brody growth function ,and to study non-genetic effects on growth traits.Statistical program SAS was to analyze variance to study the effect of gender, birth year, breed, and interaction between gender and breed in growth traits, and Duncan test were used to compares means. Results show that the real weight of local cow sets, from birth,1.5month, 3month, 6month,12month, 18month,were (23.0±0.46) kg, (40.25±0.51) kg, (64.26±1.03) kg, (110.8±2.24) kg, (216.43±3.91) kg, (277.82±1.97) kg respectively. Growth function constant a,b were analyzed and the estimates of growth function a , b were (14.07) kg, (0.56) kg respectively and the value of coefficient fitting model was R2=0.98. This study proved that Brody function is fitting to treats growth curve of local cattle, sets in southern Syria from birth to 18 months age. Results of variance analyze showed non-significant effect of gender in (a) and (b) treats, model fitting to weigh increase (R2), weigh in birth and weigh at 1.5month, No-significant differences found between males and females for these treats, but Significant effect of gender in weigh at 3month, 6month, 12moth, 18month, and the higher weight for males. Results of variance analyze showed non-significant effect of year birth in (a) and (b) treats, model fitting to weigh increase (R2), weigh in birth and at 3month, 6month, 12month, No-significant differences found between study years for these treats, otherwise year of birth effected significantly in weigh at 1.5month, 18month, and significant differences found between study years for these traits. Results of variance analyze showed a significant effect of breed in (a) and (b) traits, model fitting to weigh increase (R2), weigh in birth and weigh at 3month, 12month, and significant differences found between local cow groups(Akshi,Shami,Golani), but non-Significant effect of breed in weigh 6month, 18month,and non-significant differences between that groups for these traits. This study proved that function was fitting to describe growth curve of local cow groups in south Syria from birth up to 18 months old, although a little number of parameters (a,b) which can be explained biological and this is very important for selection besides to some non-genetic factors effect such as (gender, year birth, breed) in growth traits.
Key Words: local cattle groups, growth curve, function growth, weight, Syria.