الفهرس 
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Abstract
The current study was carried out to investigate the effects of age and sex on the reproductive and productive performance as well as some physiological and immunological responses of two separate broiler breeder flocks and their offspring. (Indian River (IR) and Hubbard, aged 35 and 60 WOA, respectively), at the beginning of the trail. Blood samples were collected from 20 randomly chosen broiler breeder chickens (10 males and 10 females) to evaluate hematological parameters, antibody titers, and some plasma biochemical constituents, which were analyzed at 60, 62, and 64 WOA in the IR strain and at 35, 37, and 39 WOA in the Hubbard strain. Performance traits included feed consumption, body weight, egg production rate, egg weight, egg mass, and FCR. Also, hatchability%, fertility%, egg and chick quality, and maternal immunity at hatch were determined biweekly.
Results showed that the female breeder’s age of both strains had a significant effect (P ≤ 0.05) on body weight, egg mass, hatchability%, eggshell%, and chick length, while there was no significant effect (P > 0.05) on eggshell breakage force, Tona score (blew score 100), or egg weight loss. IR female breeders’ age significantly affected egg production rate, FCR, fertility%, Tona score (of all chicks), and yolk-free body mass (YFBM %), while Hubbard female breeders’ age did not affect them.
Plasma total protein, globulin, triglycerides, uric acid, calcium, and phosphorus concentration levels were significantly affected by flock age in the IR strain, while albumin, A/G ratio, and creatinine concentration levels were the most affected parameters in the Hubbard strain. A similar trend was recorded in albumin, triglycerides, cholesterol, calcium, and glucose according to the sex effect. A non-significant decrease in the geometric mean of antibody titers for NDV, AIV, and transfer rate was recorded in both strains as affected by female breeder age.
The sex of breeders had a highly significant effect on hemoglobin concentration, RBCs count, and packed cell volume (PCV) in the Hubbard strain.
In contrast, for the IR strain, breeder age and sex had no significant effect on blood indices, and similar results were recorded for the sex effect, but age significantly affected the blood indices.
This thesis exclusively provides baseline data on hematological and biochemical parameters for Indian River broiler breeders. In conclusion, ageing has a deleterious effect on female breeders’ immune system, which could negatively affect their progeny at an early age. In addition, both age and sex had a significant influence on some hematological and biochemical parameters in birds. Furthermore, the detrimental impacts of broiler breeders aging on productive and reproductive parameters require further investigation.