Nutrient digestibility of Mucuna (Mucuna pruriens var. utilis) bean in guinea fowl (Numida meleagris, L): Effects of heat treatment and levels of incorporation in diets

Abstract

Mucuna pruriens var. utilis is a legume, the seeds of which are scarcely used in animal diets owing to their high content of 3,4-dihydroxy-L-phenylalanine (L-Dopa). 2. Experiments were conducted on guinea fowl to assess the effects of two types of heat processing (cooking and toasting) on chemical composition and nutrient digestibility of Mucuna seeds offered alone or incorporated at three concentrations (40, 120 or 200 g/kg) in complete diets. 3. Diets containing 200 g/kg seeds had more crude fibre and less ether extract. L-Dopa content increased with the amount of Mucuna inclusion. Cooking reduced markedly L-Dopa content while toasting had no effect. When fed alone, Mucuna seeds dramatically decreased feed intake. 4. Feed intake (FI) and body weight gain (BWG) were not influenced by the complete diets. Cooking significantly increased crude fibre digestibility. 5. It is suggested that cracked and cooked Mucuna bean can be incorporated at a safe level of 120 g/kg in complete diets for guinea fowl production. INTRODUCTION Mucuna pruriens var. utilis, a member of the Leguminosae plant family, is a crop increasingly adopted in the tropics to improve fertility of agricultural soils (Ayala-Burgos et al., 2003). Besides good resistance to pests and easy growth during fallow periods, the interest of this plant lies in the high nutritive value of Mucuna seed. Unfortunately, anti-nutritional factors, the most important of which is L-Dopa (3,4-dihydroxy-Lphenylalanine), a well-known neurotoxic amine (Seigler,