Investigation of aging physiology in broiler breeder roosters and possibilities of delaying aging

In this thesis, effects of calorie restriction, supplementation of bee products (royal jelly+apilarnil) and ad-libitum feeding on aging of broiler breeder roosters were investigated and these effects were comparised with commercial restricted feeding programme used routinely. Within the scope of the thesis, body weight, feed consumption, mortality, semen production and quality, some biochemical properties of blood (blood lipids, glucose) and hormones (insulin, corticosterone, testosterone), lipid peroxidation, oxidative stability and parameters of welfare (tonic immobility, feather score) were investigated. Fifty-six weeks old commercial broiler breeder roosters were used in the project. The study continued for 18 weeks. The following treatment groups were established in the experiment. 1. Group - Control- Commercial restricted feeding programme (135 g/day) 2. Group – Ad libitum feeding programme (ADL) 3. Group - Royal jelly (200mg/day/bird) and apilarnil (5g/day/bird) added diet (BP). 4. Group - Calorie restriction was applied about 45% of standard feed composition (CR). During the experimental period, the highest average live weight was determined in ADL group. The lowest average live weight during the first 14 weeks was determined in KS group. Low body weight was compensated in KS group. During the trial, mortality of roosters in ADL and CR groups were found significantly higher than other groups. Ad libitum feeding, bee products supplementation and calorie restriction treatments did not cause a significant oxidative stress during the experiment. However, MDA level and SOD activity were increased significantly in ADL rooster's retina at the end of experiment. This finding indicated that there was oxidative damage in retina of ADL roosters. Ad libitum feeding, bee products supplementation and calorie restriction treatments did not significantly affect blood lipids (triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol) and glucose levels. Ad libitum feeding, bee products supplementation and calorie restriction treatments affected semen production and quality significantly. At the end of the experiment the lowest semen volume and sperm motility and highest dead sperm % were found in roosters of ADL group. The highest semen volume and sperm motility and lowest dead sperm % were obtained in BP group. As a result, it has been determined that dietary apilarnil and royal jelly supplementation may be an effective method to prevent age-related decrease in sperm production and quality in broiler breeder roosters. Keywords: Broiler breeder rooster, reproductive performance, aging, lipid peroxidation, royal jelly, apilarnil, caloric restriction.