Effects of moist heat and dry heat on the nutritional value of velvet beans (Mucuna pruriens Var. Utilis) for the laying hen-

Abstract

A 112-day feeding trial was conducted to compare roasting and autoclaving as methods of heat treatment for improving the nutritional value of velvet beans (Mucuna pruriens) for the laying hen. One batch of beans was autoclaved at 211 for 30 minutes. Another batch was mixed with an equal amount of sand and evenly roasted in an open pan. Representative samples of both beans were analysed for crude protein, fibre fat, ash, calcium, and phosphorus. The chemical analysis showed that velvet beans contained 27.1% CP, 3% CF, 8.9% Fats, 3.1% Ash, 4.6% Ca and 1.4% P. The beans were subsequently incorporated to constitute l0 and 20 percent of the experimental diets and fed to laying hens. The results revealed an overall improvement in the performance of laying hens when fep autoclaved beans. The addition of autoclaved beans up to the level of 20 percent had no detrimental effect on egg production and egg quality characteristics. But when roasted beans constituted 20 percent of the diet, there was a significant (P < 0. 05) reduction in egg production, egg mass out put and per cent marketable eggs. It was concluded that autoclaving was a better method of heat treatment than roasting, for velvet beans fed to the laying hens.

Keywords: Heat treatment, velvet beans, nutrition, hens

Tanzania J. Agric. Sc, (2000) Vol. 3 No. 2, 123 -128