Discussion Committee:
Dr. Maen Samara - Chairman
Professor Dr. Adnan Shqueir - External Member
Dr. Rateb Aref - Internal Member
Authors:
Othman Hashem Hassan Shahadi
Abstract:
An experiment with broiler breeder pullet's was carried out to determine the effect of pattern of light stimulation and pullets body weight at 20 wk of age on body weight and age at onset of egg laying. Two light stimulation treatments were used: abrupt light stimulation (ALS) in which hours of light were increased to 10 hr at 21 wk, 12 hr at 5% egg production, 14 hr at 35% egg production, and finally to 16 hr at 65% egg production; and step-up light stimulation (SLS) in which hours of light were increased to 12 hr at 21 wk of age, then by half an hour weakly until 16 hrs of light are attained at 29 wk of age.
Pullets were randomly assigned to one of three body weight groups: low weight (1800 g), medium weight (2200 g), or heavy weight (2600 g) at 20 wk of age. The results obtained indicated that pattern of light stimulation and weight at 20 wk did not markedly affect egg production, however, pullets exposed to SLS or ALS produced the lightest eggs. A numerical advancement occurred in age at first egg due to SLS. Significant weight gain occurred in low weight pullets due to SLS. The results of this experiment indicated that SLS of low weight broiler breeder pullets represents a viable means for advancing onset of lay, and increasing weight gain at onset of lay