Effect of iodine supplenentation to low energy diets on productive and reproductive performance in laying hens of local Sinai strain [electronic resource].

Includes reference.

A total number of 297 Sinai hens (270 females and 27 males) 42-wks-old were used, weighed and divided into nine treatment groups, three replicates each, to investigate the effect of Iodine supplementation to low metabolizable energy (ME) layer diets in a factorial design (3x3) on laying performance, egg quality parameters, reproductive performance and nutrients digestibility as well as some blood constituents during the late stage of laying period (42-58 wks of age). The dietary ME of treatments were 2766 (as control); 2655 and 2565 kcal ME/kg, with three iodine levels of 0.3 (as control); 1.2, or 2.4, mg iodine/ kg diet. Results obtained could be summarized as the following: 1- Decreasing ME content in the Sinai layer diet resulted in a significant decrease in body weight and body weight gain (BWG) while diet supplemented with 2.4 mg/ iodinekg diet had the highest BWG compared to other groups. Also, BWG was significantly affected due to the interaction between iodine and ME. 2- Laying rate percentage and egg mass (g/hen) was significantly decreased by dietary contained 2565 Kcal/Kg diet Conversely, the hens fed diet 1.2 and 2.4 mg 1/Kg diet significantly improved the laying performance. Also, the superiority of the diet contained 2655 Kcai/Kg with 2.4 mg iodine /Kg diet where it was significantly greater laying performance than all other treatments. 3- No significant effect was observed on reproductive performance by feeding different levels of ME, while hatchability percentage was significantly improved as dietary supplemented with 1.2 and 2.4 iodine/ kg diet. Also, the best significant value of hatchability was recorded by the interaction between 2655 Kcal ME/kg and 2.4 mg iodine/ kg diet. 4- Decreasing ME content from 2766 to 2655 and 2565 Kcal/kg diet showed linear significant higher feed consumption. While, only the low level of ME (2565Kcal/Kg diet) significantly decreased feed conversion ratio compared to the control.

Summary in Arabic.

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