Histological findings of the bursa of fabricius in broiler chicks supplied with the methionine supplement methio grow

الملخص EN

The study aimed to determine the effects of higher levels of methionine supplementation than the recommended NRC level in the diets on the weight and histomorphology of the bursa of Fabricius as indicators for the immune status of broiler chickens.

A total of 60, one-day-old, broiler chicks were divided into 4 groups (Control, T1, T2, and T3 groups) and accommodated in separate pens at the College of Agricultural Engineering Sciences, University of Sulaimani.

The chicks were fed on a starter diet for the first 11, a grower diet on days 12-25 and a finisher diet on days 26-42.

The methionine supplement MethioGrow was added daily to the drinking water of the treatment groups T1, T2, and T3 by the levels 0.

25, 0.

50, 0.

75 ml per liter respectively for 42 days, whereas those of the control group were provided with additives-free drinking water.

On day 42, the chicks were euthanized and the bursa of Fabricius was excised, weighed by a sensitive balance and 5μm thick tissue sections were obtained, stained by Hematoxylin and Eosin stains and examined by a light microscope to examine the histological findings.

The weights' mean of the bursa of Fabricius on day 42 was significantly higher in groups T2 and T3 than in the control group and the microscopic examination of the bursa of Fabricius revealed slight increase in numbers of lymphocytes in the medullary region of the lymphoid follicles in chicks of the treatment groups 1 and 2 (T1 and T2) and slight increase in lymphocytes in both the cortical and medullary regions of the lymphoid follicles in chicks of the treatment group 3 (T3) in comparison with chicks of the control group.

In conclusion, the obtained results revealed that supplementation of higher levels of methionine in the broiler diet than the level recommended by the NRC has positive effects on the immune status of the broilers and they support the suggestions of previous reports that referred to the insufficiency of methionine requirements of broiler based on recommendations of NRC to meet the real requirements of the commercial poultry farms.