TY  - JOUR
T1  - Specificities of the Local Kids’ Genotypes Expression Towards Arid Conditions in Southern Tunisia
AU - , Mouldi Abdennebi AU - , Amor Gaddour AU - Najari, Sghaier AU - , Mabrouk Ouni 
JO  - Research Journal of Biological Sciences
VL  - 2
IS  - 3
SP  - 301
EP  - 306
PY  - 2007
DA  - 2001/08/19
SN  - 1815-8846
DO  - rjbsci.2007.301.306
UR  - https://makhillpublications.co/view-article.php?doi=rjbsci.2007.301.306
KW  - Southern Tunisia
KW  -environmental factors
KW  -kid’s growth
KW  -genetic specificities
KW  -Local goat
AB  - About 5000 kid’s weights registered during four years in 9 herds raised in the Tunisian arid area were used in the aim to identify some genetic specificities of the local population productive behaviour towards harsh conditions. The analysis of kid’s growth under arid regions conditions shows a particular aspect of the genotypes expression in arid environment. The nature of the non-genetic factor effects on kid’s phenotypes distribution and parameters reveals a direct impact on the application of quantitative genetic methodologies for animal improvement. The expression of the "best" genetic potentialities seams to be limited by a maximum level defined by environmental factors. The normal distribution of kid’s performances is not verified, especially in dry years, where the right tail of the bell curve disappeared. The statistical importance of certain parameters such as the means and the variance is modified. The construction of the mixed model could, in this special case, induce a bias or increase the variance of the prediction error. These considerations impose a revision of hypotheses and methodologies of the quantitative genetics for the livestock improvement in arid regions.
ER  -