EFFECT OF SELECTION FOR BODY WEIGHT ON BODY MEASUREMENTS AND CARCASS TRAITS IN EL-SALAM STRAIN OF CHICKEN IN EGYPT
Journal of Animal and Poultry Production
This work was carried out at Sakha, Poultry Production Research Station, Animal Production Research Institute, Ministry of Agriculture, during three successive generations to study the effect of the individual selection for high body weight at marketing age (12 weeks) on body measurements (shank length, keel length and body circumference), carcass traits (dressing, breast meat, thigh meat percentage, giblets, and offal percentages of live body weight) in El-Salam strain of chicken. Also,
... icken. Also, estimates of the genetic parameter for these studied traits. A total number of 789 pedigreed birds obtained from 697 dames mated by 92 sires through three successive generations. The chicks in each generation divided into two lines, first is the selected line and second is the control line. The pullets were transferred to individual laying cages until the end of production phase. Artificial insemination was used during the production season by eight females to each male. In base and later generation, checks were selected according to body weight as equal or greater than average of the flock at 12 weeks of age. Number of 36 checks (18 males and 18 females; 6 from each generation) from selected line and 18 checks (9 males and 9 females; 3 from each generation) from the control one at 12 weeks of age were slaughtered to measure the previous carcass traits. Results showed that body weight at 12 weeks of age, increased (p˂0.05) by generations in selected line more than the control line. Also, there were significant differences between generations, lines and sex in body weight and body measurements such as shank length, keel length and body circumference. Selected and unselected males were better than females within and between lines for the most of the studied traits. Chicken males had higher body weight than females in all generations. There were significant differences between generations, lines and sex in carcass traits [dressing, breast meat, thigh meat, giblets (gizzard, heart, and liver) and offal (blood, head, wings, shanks, feather, and viscera) percentages]. Heritability estimates for body weight, shank length, keel length and body circumference at 12 weeks of age were 0.55, 0.44, 0.51 and 0.48, respectively. Heritability estimates for dressing, breast meat, thigh meat, giblets, and offal percentages were 0.48, 0.47, 0.45, 0.52 and 0.47, respectively. All genetic correlations among body weight, body measurements, and carcass traits were positive, ranging from 0.11 to 0.91. All phenotypic correlations between different studied traits were positive ranging between 0.29 and 0.43. It could be concluded that the selection should be carried out to improve body weight, body measurements and carcass traits at marketing age (12 week) in El-Salam strain of chicken in Egypt.