Effect of pinealectomy and exogenous melatonin administration on jejunal melatonin level and early broiler performance*

The presence of melatonin and the enzymes involved in its synthesis has been proved in the gastrointestinal tract of several species but the factors affecting the level of MT in gut tissue have not yet been ascertained. To elucidate the effect of pinealectomy and exogenous melatonin administration on jejunal melatonin level and early broiler performance, 144 one-day old chicks were divided into three groups i.e. control, sham operated and pinealectomised. Half of birds from each group were supplemented with exogenous melatonin @ 5ppm while the other half received a placebo up to 20 days. Experimental birds were sacrificed at day 10 and 20 to collect jejunum. Melatonin level in jejunal tissue was estimated using reverse phase HPLC. Results indicate that while pinealectomy do not produce any significant variation exogenous administration significantly increases (P<0.05) gut melatonin level, suggesting that during photophase most of melatonin present in gut tissue is of local origin and not of pineal origin. Feed conversion ratio in Melatonin supplemented group was also better suggesting that higher gut melatonin have a favourable effect on FCR.