GENETICAL STUDIES ON CHICKENS A comparative study on the efficiency of different methods for live body weight selection in the fowl

Abstract

Two experiments were carried out at Borg Elarab Poultry Research

Station, Ministry of Agriculture.

In the first experiment, two lines (selected and control) from Baheij chickens had been developed from two way cross of chickens including two strains (Alexandria and Silver Montazah). One line was selected for improving body weight, breast width, keel length and shank length at 8 weeks of age using independent culling levels and the second line was an unselected control line which was drawn at random and kept without any selection. In the second experiment, three lines (high, intermediate and low) from

Baheij chickens were classified according to the specific gravity of their body weights The purposes of the present study were

1. Studying the efficiency of selection for body weight, keel length, shank length and breast width, using the independent culling level method in a population of Baheij chickens.

2. Studying the efficiency of selection for live body density as a non­ traditional method for improving the performance of Baheij chickens.

The main results and conclusions can be summarized in the following :

1. After two generations of selection, the divergence in body weight between selected and control females (118 g) was significantly higher than that in the base generation (64 g). 2. The mean divergence between selected and control lines forbreast width, keel length and shank length were .5, .8 and .6 em for males in .the base generation of selection and decreased after two generations of selection to -.1, .3 and .2 em, respectively. The same trend was observed for females.