PHYSIOLOGICAL BASIS CONTROLLING EGG SHELL QUALITY IN DIFFERENT BREEDS OF LAYING HENS

Abstract

Three breeds of chickens were used in the present study (Fayourni, Rhode Island Red and Golden Montazah). All birds of each breed (300 birds) were used to determine the productive performance. Blood samples were taken from 30 birds of each breed at sexual maturity and at the peak of egg production. -Major results can be summarized as follows: 1- Breed had no significant effect on serum progesterone level at sexual maturity and at the peak of egg production. Productive status had no significant effect on serum progesterone level.

2- Breed had significant effect on serum estradiol level at sexual maturity but breed had no significant effect on serum estradiol level at the peak of egg production. Productive status had significant effect on serum estradiol level. 3- Breed had no significant effect on serum alkaline phosphatase level at sexual maturity but breed had significant effect on serum alkaline phosphatase level at the peak of egg production. Productive status had significant effect on serum alkaline phosphatase level. 4- Breed had no significant effect on serum calcium level at sexual maturity and at the peak of egg production. Productive status had significant effect on serum calcium level. 5- Breed had significant effect on serum phosphorus level at sexual maturity and at the peak of egg production. Productive status had no significant effect on serum phosphorus level. 6- Breed had significant effect on serum total protein level at sexual maturity and at the peak of egg production. Productive status had no significant effect on serum total protein level. 7- Breed had significant effect on serum total lipids level at sexual maturity and at the peak of egg production. Productive status had significant effect on serum total lipids level. 8- Breed had significant effect on productive traits (body weight at sexual maturity, first egg weight, first 10 eggs weight, egg number, egg weight, egg mass) and egg shell quality (shell weight, shell thickness and shell calcium percent). Breed had no significant effect on age at sexual maturity and shell weight percent.