مقارنة بين تأثير نظامي الإضاءة (المتناقصة و الثابتة القصيرة)‎ للفراخ في بعض المؤشرات الإنتاجية لدجاج البيض

Abstract EN

The aim of this study is to compare between the decreasing and the short – constant lighting system during the growth phase of chicks and the effect of the two lighting system on productivity indicators in laying hens .

The study which employed 504 chicks of the hybrid ( Babcock B- 300 )that produce white egg was carried out in the poultry house of the faculty of agriculture Damascus university .

The chicks were kept from age day 1 up to 60 weeks .

The chicks were randomly divided into two group each containing 252 chicks .

Each group contained three replicates each of which contained 84 chicks.

All the chicks were subjected to similar nutritional , health and rearing conditions.

As for the lighting system employed on two groups during the growth phase (from day 1 up to 18 weeks ) was rather different and as follows : decreasing lighting system was employed during the growth phase .

Short – constant lighting system was employed during the growth phase .

However , during the productive period( 19 – 60 weeks ) both groups were subjected to the increasing lighting system .

The results showed that : The sexual maturity age was significantly 10 day earlier for group G2.

The egg laying rate for the whole production phase was significantly higher by 5% for G2 .

The average egg production / hen (H.D ) for the whole production period for G2 was significantly higher by 14.6 egg .

The average egg weight for the whole productive period was significantly higher by 1 g .

The average egg mass produced / hen for the entire production phase was significantly higher for G2 by 632 g.