DIRECT RESPONSE DUE TO SELECTION FOR BODY WEIGHT AT EIGHT WEEKS OF AGE IN DANDARAWI CHICKEN: BODY WEIGHT AND CONFORMATION.

This study was carried out at the Poultry Farm of Poultry Production Department, Faculty of Agriculture, Assiut University, through two successive generations to study the effect of selection for high body weight at eight weeks of age on body weight and body conformation measurements (shank length and keel length) in Dandarawi chicken. The study involved 2932 pedigreed chicks obtained by mating 96 sires with 935 dams through two successive generations. The chicks in each generation divided into two lines, line (S) selected for high body weight and line (C) is the control line. Chickens were weighed from 0 to 20 weeks of age, shank length from 4 to 20 weeks of age and keel length from 8 to 20 weeks of age was measured for the two lines over generations.

The results showed that body weightsat zero,4, 8 and 20 weeks of agewere significantly different (P≤0.01) between the two generationsthat improved by the individual selection. Also, there were highly significant differences between linesin body weight from zero to 20 weeks of age (P≤0.01) and the selected line had higher body weight than the control line over generations.There were highly significant differences between sexesin body weight from 4 to 20 weeks of age (P≤0.01) which male body weights from 4 to 20 weeks of age were higher than that of females in the two lines over generations. Sexual dimorphism was gradually increased from 4 to 20 weeks of age.There were highly significant differences (P≤0.01) between generations, lines and sex in shank lengthand keel length at all agesin the present study. It found some significant interactions between the main effects considering the different studied traits which mean that the effect did not due to the main effects, but it may refer to other factors than the main effects. Also, there were insignificant interactions between the main effects which mean that the variations between the studied traits were due to the main effects.
It concluded that by using selection at 8 weeks of ageled to improve body weight and body conformation in Dandarawi chicken.