Abstract
The study was conducted to assess the effect of breed, age and sex ratio on fertility and hatchability of Saudi Arabian Baladi breed of poultry and to compare its' performance with that of Leghorns which, were maintained under similar conditions. 396, twenty week-old pullets of Baladi and Leghorn were randomly divided into three experimental groups of three replicates each and were assigned to one of the following cock to hen ratio 1:6, 1:10 and 1:14. The birds were randomly allotted to 9 2mx2m floor pens in an environmentally controlled house. 35 eggs of each replicate were collected at the last week of each production period and used for the study. Fertility (F) and hatchability of total eggs (HT) percentages were significantly affected (P < 0.05) by breed (B), treatment (T), age (A) and TxA interaction whereas other studied traits were not affected. Leghorn hens had significantly (P < 0.05) (9. write 0.05) higher F and HT and tended to have higher FH and lower TEM compared to their Baladi counterparts. F and HT of 1: 6 were significantly (P < 0.05) the highest followed by 1:10 and that of 1:14 sex ratio were the lowest at all studied age periods. Baladi and Leghorn hens had similar response to the different sex ratios used in the experiment though Leghorn hens tended to have higher values. From the results reported herein we suggest that breed, age and sex ratio significantly affect fertility and hatchability of total eggs but not fertile hatchability and embryonic mortality. The highest fertility and hatchability values were achieved by 1: 6 sex ratio and early age periods. The study also showed that lower sex ratio might enhance old hens' ability to be fertilized.