Histological examination and carcass characteristics of broiler chicken dosed varying levels of onion extract

This experiment was designed to determine the effect of onion extract on histological response and carcass characteristics of finisher broilers. Sixty day old chicks of Cobb 500 strain were used for this study which lasted for four weeks. The day old chicks were purchased from Ibadan, Nigeria. The chicks on arrival were brooded for four weeks using normal starter feed (New hope brand). At the expiration of four weeks brooding period the broilers were randomly assigned to three treatment groups with three replicates in a completely randomized design (CRD). The onion bulbs were purchased from Ogige market in Nsukka town, Enugu State, Nigeria. The aqueous onion extract were prepared by slicing, soaking and extracting the active ingredients from the onions. The extract was diluted at different concentrations such as; 0.5g/ml, 1.0g/ml and 1.5g/ml of clean water for T2, T3 and T4 respectively. T1 had no onion extract and as such served as control. The onion extracts were administered to the birds every 48 hours using dropper. Water and feed were given ad libitum to the birds. The result obtained showed normal hepatocytes with acinar-like arrangement and central vein with no abnormal changes in all the organs examined. In conclusion, it has been revealed that the dietary onion extract enhanced the histological features and carcass characteristics of finisher broilers without any detrimental effects on the organs. We therefore, recommend the use of T3(1.0g/ml) which had highest dressed carcass yield to farmers for optimum gain.