Authors : Najari Sghaier , Gaddour Amor , Ouni Mabrouk , Abdennabi Mouldi and Ben Hamouda Mohamed
Abstract: During four years, a weighing program allowed collect about 4900 of data of 722 indigenous kids raised in 9 herds in the Tunisian arid zone under pastoral husbandry mode. A Gompertz model was applied to estimate kids` weights at some standard ages 10, 30, 60, 90, 120, 150 and 180 days. A GLM procedure was applied to decompose the total variance of the kid’s traits. A means comparison test (SNK, = 0.05) was applied to identify homogenous class by factor. Results show that the GLM determination coefficient R� remains lower than 87% of all studied traits due to the observed data structure. All traits seem to be affected by the significant effects (p< 0.001 or 0.05) of the factors related to the restrictions and the irregularity of the technical and natural environment of pastoral husbandry. The non-genetic factors impact increases with kids’ age and requirements. Growth traits varied with year, herd, month of birth and natural region. The year factor plays an important role upon the kid’s weight and it evolution till 6 months age. The sex, birth mode and mother age acts only during first 2 months age. Regarding the birth season effect, regrouping kidding period allows improving herd productivity. So, arid environment affects both quantitatively and qualitatively individual kid’s growing behaviour and have to be considered for local goat rational genetic improvement modelling and planning.
Najari Sghaier , Gaddour Amor , Ouni Mabrouk , Abdennabi Mouldi and Ben Hamouda Mohamed , 2007. Indigenous Kids` Weight Variation with Respect to non Genetic Factors under Pastoral Mode in Tunisian Arid Region . Journal of Animal and Veterinary Advances, 6: 441-450.