In order to evaluate the effect of increasing the level of vitamin A in wheat-based diets on performance, immune system, and nutrient digestion in broiler chickens, 200 broilers of Ras 308 strain were used in a completely randomized design with 5 treatments and 4 replications.

Experimental treatments included wheat-based diets containing vitamin A at levels of 1500, 4500, 7500, 10500, and 13500 international units per kilogram (IU/kg). In order to check the immune response, the injection of sheep red blood cells (SRBC) and skin basophilic sensitivity test (CBH) were performed. Nutrient digestibility was measured at 21 days. At the age of 42 days, 2 birds were selected from each replicate and killed after blood sampling.

In order to measure the viscosity of digestive juice, the contents of jejunum and ileum were sampled. To check the antioxidant status, the concentration of malondialdehyde (MDA) was measured in serum samples. Different levels of vitamin A did not affect yield, CBH response and nutrient digestibility.

Vitamin A at the level of 13500 IU/kg increased antibody titer against SRBC. Moderate levels of vitamin A (4500 and 7500) decreased serum MDA concentration. Medium and high levels of vitamin A (7500 to 13500) decreased the viscosity of jejunum contents and also decreased the relative weight of the entire digestive system.

Vitamin A at the level of 4500 IU/kg reduced abdominal fat. Vitamin A at the level of 7500 IU/kg increased the production index. In general, according to the positive effects mentioned above, as well as according to the production index and cost per kilogram of weight gain and meat production, the use of IU7500 level is recommended.

writers:

Soghari Hatami

Fariborz is fake

Mohammadreza Akbari

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