The Nutritional Value of Extruded Beans (Phaseolus vulgaris) and Extruded Mixtures of Beans and Soybeans in Chick Diets

Two experiments were conducted to evaluate extruded small red beans (Phaseolus vulgaris) (recleaned culls) and extruded mixtures of beans and soybeans as protein sources in chick diets. In Experiment 1, protein efficiency ratios (PER) were determined for week-old chicks fed diets for 2 weeks containing all the protein (13%) from either soybean meal, extruded soybeans, autoclaved (121 C for 15 min) beans, 135 C extruded beans, or 150 C extruded beans. All of the bean treatments, with or without supplemental methionine, resulted in lower (P<.05) PER than the soybean treatments similarly supplemented. No differences (P>.10) in PER were noted between autoclaved or 150 C extruded bean treatments; however, 135 C extruded bean treatments resulted in lower (P<.05) PER. In Experiment 2, day-old chicks fed diets containing one-half of the total dietary protein from extruded beans had lower (P<.01) 2-week gains and gain-to-feed ratios than chicks fed soybean meal. Chicks fed diets containing an extruded mixture of one-third beans plus two-thirds soybeans with supplemental methionine had similar 2-week gains and higher (P<.05) gain-to-feed ratios compared to chicks fed the soybean meal diet with supplemental methionine. Chicks fed diets containing an extruded mixture of two-thirds beans plus one-third soybeans with supplemental methionine had decreased (P<.05) 2-week gains but similar (P>.10) gain-to-feed ratios. The method of extrusion (separate or together) or moisture pretreatment during extrusion (dry or wet extrusion) of the bean and soybean mixtures had no effect (P>.10) on chick performance when fed. In both experiments, supplementation of diets with methionine resulted in greater increases in weight gain and gain-to-feed ratios for chicks fed the bean containing diets compared to chicks fed the soybean diets. It appears that dry extrusion of beans and soybeans together, especially if the proportion of beans in the mixture is one-third or less, offers a practical and easy method for heat processing cull beans for use in poultry diets.