Response of laying hens to dietary vitamins A, E and selenium supplementation during summer months

الملخص EN

The current study aimed to investigate the effects of extra dietary supplementations of vitamins A, E and Selenium and their interactions on the performance of laying hens during summer months.

A total of 243 Bovans laying hens 42 weeks old were randomly distributed into a factorial design experiment (3×3×3); including 3 levels of vitamin A (0, 8000, 16.000 IU/kg diet), 3 levels of vitamin E (0, 250, 500 mg/kg diet) and 3 levels of inorganic-selenium, (0, 0.25, 0.50 mg/kg diet).

Results obtained showed that most values of live body weight and change in live body weight did not significantly differ due to A, E and Se supplementations and their interactions at all ages studied.

Increasing the level of supplementations was associated with the decrease in feed intake and improving feed conversion.

The effects of supplementations and their interactions were highly significant (P≤0.01) on feed intake and feed conversion.

Increasing the level of vitamin A up to 16000 IU/kg diet had the highest (P≤0.05) monthly egg number and egg mass.

Vitamin A increased (P≤0.05 and 0.01) each of egg length at 46 and 50 weeks of age and haugh units at 54 weeks of age.

The higher level of supplemented dietary vitamin E led to a significant (P≤0.05) decrease in shell thickness and haugh units.

Most of the egg quality traits fluctuated significantly (P≤0.05 and 0.01) with the high level of Se.

The interactions among supplementations did not significantly affect egg quality traits.

In conclusion, the results of the present study demonstrate that it may be suggested use each of vitamins A and E (together) at extra levels up to 16000 IU/kg diet of vitamin A and 500 mg/kg diet of vitamin E.

Se levels need more investigations to detect its suitable level alone or with vitamin E in laying diets to reduce the negative effects of summer months.