EFFECT OF DIETARY CHOLECALCIFEROL LEVELS AND GIBBERELLIC ACID ON PRODUCTIVE AND REPRODCTIVE TRAITS, SERUM PROFILE AND BONE MINERLIZATION OF LAYING QUAIL

Abstract

An experiment was conducted to investigate the effect of supplemental cholecalciferol (CC) separately or in combination with gibberellic acid (GA3) on productive and reproductive traits, bone mineralization and serum profile of aged female quail. For this purpose 128 females and 64 males (at 42 week of age) were assigned to eight experimental groups. For ten weeks, each of the first four groups was fed on one of the following four graded levels of CC, 450, 900, 1350 or 1800 IU/kg diet. While, the other four were received the same CC levels plus 5 ppm GA3. The main results indicated that, egg production percentage and egg mass were negatively affected by supplemental CC at 450 IU/kg. However, addition of GA3 improved egg production and egg mass at all levels of CC. Feed conversion ratio (g feed / g egg) improved linearly with increasing CC levels and the improvement was more remarkable with supplemental GA3. Feed consumption values were not affected neither by CC levels nor by GA3. Gibberellic acid supplementation significantly reduced serum concentration of albumin. Similarly, values of albumin to globulin (A/G) ratio indicating better immune response. While, serum globulin was not affected. Concentration of both calcium and phosphorus were significantly increased in blood serum, as well as tibia of GA3 groups. Hatchability percentage was reduced but, early and late embryo mortality were increased due to feeding suboptimal level of CC (450 IU/kg), while GA3 supplementation caused an improvement in hatching traits. Egg shell percentage improved with adding GA3 into diets, this improvement may be related to increase calcium solublization. Tibia weight was improved by increasing CC level and GA3 administration. Tibia ash percentage adversely affected by low CC level while GA3 addition caused a slight increment. It can be concluded that, supplemental 1350 IU CC with GA3 is needed for better productive and reproductive performance of old quail hens.