Effects of dietary methionine source on productive performance, blood chemical, and hematological profiles in broiler chickens under tropical conditions

This study was conducted to investigate the effects of supplementation of dl-methionine (DLM) and liquid dl-methionine hydroxy analog free acid (MHA) in diets on productive performance, blood chemical, and hematological profiles in broiler chickens under tropical conditions. In all, 216 commercial male broiler chicks were used to compare two dietary methionine sources, DLM and MHA. Chicks were raised for 35 days in battery cages situated in high ambient temperature and relative humidity open-side housing. The chicks were divided into three treatments in six replications with 12 chicks each. A completely randomized design was used. The treatment groups were (1) control group (methionine and total sulfur amino acid deficient diet), (2) supplementation of DLM as the methionine source in diet, and (3) supplementation of MHA as the methionine source in diet. The productive performance of DLM and MHA was not significantly different. Both supplementation of DLM and MHA significantly improved final body weight, body weight gain, average daily gain, and feed conversion ratio when compared to the control group (P < 0.01). Both DLM and MHA supplementation significantly increased the plasma cystine concentration level (P < 0.05). The use of DLM enhanced the plasma methionine concentration (P < 0.01) and increased the heterophil/lymphocyte ratio (P < 0.05). While MHA elevated the plasma taurine and uric acid concentration levels (P < 0.05). In conclusion, under tropical conditions, there was no significant difference between DLM and MHA supplementation on productive performance; plasma methionine concentration was increased by DLM supplementation, while plasma taurine and uric acid concentration were significantly increased by MHA supplementation.