An investigation on faecal N and lipid excretions in growing broilers fed false yam (Icacina oliviformis) tuber meal

Abstract

This study was conducted to determine the effect of False Yam (Icacina oliviformis) on the growth performance, some biochemical alterations of growing broiler. For this experiment, 50, 20-day old growing broilers were randomly allocated to five dietary treatments: Raw tuber- (without alcohol treatment) @ 6%, raw tuber (70% alcohol treated) @ 6%, raw tuber @ 9%- were incorporated in a maize-soy based diet while commercial practical diet was used as control diet. Both control and treatment group were fed 60 gm feed daily (restricted feeding) up to the end of the experiment. The completely randomized design of the experiment was used. Pre-treatment of the meal with ethanol resulted in a significant increase in N intake and apparent digestibility and as well as the body weight gain. However, the Blood Urea Nitrogen (BUN) was found to be increased as compared to those non-alcohol and control groups. Broilers fed on diet based on 9% of the soaked tuber showed an elevated level of fat excretion as compared to those of others. Although, false yam supported the growth, however, apparent N retention could not have been improved by pre-treatment with alcohol and thus, the growth well below those expected. This was partly due to depression in digestion of the false yam protein and possibly to the presence of ant-nutritional factors in the meal that interfered with digestion, absorption and retention of N and lipid. The results showed that there was a significant decline (p<0.05) in the values of weight gain as the levels of false yam was increased in the diet. The results also showed that false yam may be added to broiler diets less than 6% without any detrimental effects. Furthermore, false yam may have contained potentially nephrotoxic agents that have been made- available for absorption due to ethanol treatment. Possible involvement of fibre and flatus compounds may have been linked to reduced N retention in broilers.