Effect of Body Weight Uniformity on the Productivity of Broiler Breeder Hens

Abstract

Measurements on hen-day and hen-housed egg production, hatchability, fertility, 
total hatching eggs, mortality and cracked eggs were made on eight flocks belonging to the 
Arab Company for Livestock and Development. There were 6000 females and 600 male 
parent broilers in each flock. Uniformity was calculated by taking a random sample of 7% 
of the birds in each pen and weighing them on a weekly basis. The flocks were assigned to 
uniformity groups ranging from 55% to 80%. The high uniformity group (75%-80%) 
consistently had the highest hen-day and hen-housed production overall ages, while the 
low uniformity group had the lowest hen-day production. The analysis of variance showed 
that the effects of age and uniformity group on all studied traits were highly significant. 
The effect of age x uniformity group was significant only for total hatched eggs. Percentage 
hatchability of settable eggs varied from 69.19±1.93 in the 55%-59% group to 83.93±1.65 
in the 75%-80%. The highest levels of uniformity had the highest percentage of cracked 
eggs (0.30±0.01), while the medium range of uniformity had the lowest percentage of 
cracked eggs (0.182±0.011 in the 65%-69% group). The highest fertility (86.53±1.56) was 
found in the 65%-69% uniformity group. The study demonstrates the importance of 
controlling body weight and the use of restricted feeding to achieve optimum production 
and fertility in broiler breeder hens.