Avian Production Management

FACTORS AFFECTING FERTILITY

• Age of the parent stock: There is an increase in fertility in a breeder flock between the ages of 25 to 40 weeks after which fertility gradually diminishes
• Breed: Lighter breeds like White Leghorn is more fertile than heavier breeds like the broiler breeders.
• Genetic factors: Many genes influence fertility eg: in Wyandotte the gene responsible for rose comb (RR) lowers fertility in males.
• Environmental factors: Excessive high and low temperature reduces fertility due to poor mating frequency because of the inactiveness of the birds.
• Disease conditions: Many diseases like Ranikhet disease, Mycoplasmosis, Salmonella etc., affect fertility.
• Sex ratio: Both higher and lower males to female ratio will reduce fertility. The recommended ratio in lighter breeder is 1:10-12,. In broiler breeder 1:8-10 and in J.quails 1:1-2
• The semen volume, sperm concentration and number of successful mating also alter fertility. Inseminating the birds during the after noon can lower fertility.
• Nutritional factors: Some deficiencies like vitamin A, E , Biotin, Pantothenic acid and B2 and minerals like calcium, phosphorous, sodium, Magnesium, Manganese, Zinc and Iodine lower fertility.
• Photo period: A photo period of 16 hrs per day will give optimum fertility. By either lowering the length of period to 12 hrs or increasing it to 18 hours lowers the fertility.
• Male nutrition: Male breeders should be fed with lower protein levels of 12-14% for optimum fertility.