Evaluation of Processing Methods on the Feeding Value of Grass Pea to Broilers

Abstract

Grass pea is a widely available grain legume that contains a neurotoxin ODAP that has negative effects in humans and animals. Various treatment methods were tested to select methods that are more effective. Socking and cooking at 60, 75, 90^oC and boiling temperatures were found to be relatively effective. Diets containing grass pea prepared using these methods along with diets that contained untreated grass pea and a control that did not contain any grass pea were tested in a broiler trial. Grass pea was included by replacing Noug (Guizotia abyssinica) cake. Four hundred twenty unsexed one day old Cobb broiler chicks of similar body weight were divided into seven groups of 60 and further randomly sub-divided into three replicates of 20 chicks and placed in the experimental pens were used. The study showed that total replacement of Noug cake by boiled grass pea is possible without significantly reducing performance (gain and feed efficiency). Cooking at 90^oC can also be considered pending economic evaluation since it was also similar results to the control diet (p>0.05) in terms of feed efficiency. Performance of broilers on the rations containing grass pea treated using the other methods seem to have depressed performance too much. Comparison of performance during the starter and finisher phases indicates that most of the depressing effects seem to have occurred during the starter phase. There was no visible sign of lathyrism in any of the treatment groups in this study. It is suggested that further economic analysis of using the methods be conducted. Further work on the possibility of using grass pea only during the finisher phase following the apparent reduction of the negative impacts of feeding grass pea at this stage observed in this study is also proposed.