Performance of broiler chicken fed on graded levels of Napier grass protein as replacement for fish meal

Abstract

This experiment was carried out to evaluate the performance of broiler chicken fed on graded levels of Napier grass protein as a replacement for fish meal. In Uganda, the prices of fish meal and soybean meal, which are the most commonly used protein sources are high. Fish stocks are continuously getting depleted due to over fishing and competition imposed on the lakes by both humans and the livestock sector. The poultry sector should now focus on the utilization of locally available crop resources to provide an alternative source of protein in substitution of the fishmeal. Napier grass is a locally available tropical grass that requires less water and nutrients to grow and is not competed for by humans for food as the case with Soybean meal. A total of 300 day old Cobb500 broiler chicks were randomly distributed into 15 rearing pens, each containing 20 birds. The chicks were subjected to five treatments of diets containing different amounts of Napier grass protein. Each treatment was replicated three times. The treatments contained 0%, 25%, 50%, 75% and 100% Napier grass protein fed to the birds for six weeks. The birds were evaluated for their weight gain and their respective feed conversion rates (FCR), Protein and Energy Efficiency Ratios (PER and EER respectively). Birds were weighed on a weekly basis and their mean weight gain computed while feed intake was recorded daily. The study found out that birds weighed lesser (P<0.05) as more Napier protein was added to their diets. Birds fed on 0% NP had the highest mean weight of 1632.65g while those fed with 100% NP had the lowest mean weight of 450.8g by the sixth week. The FCR was lowest for birds fed 0% NP (1.83) for the starter phase but was however lowest for birds fed at 100% NP and 50% NP (2.26) during the finisher stage. The feed intake significantly (p<0.0001) reduced with increasing inclusion levels of NP in both the starter and finisher diets. Both PER and EER of the birds significantly (p<0.0001) decreased as more NP was added to the starter diets but no significant difference (p=0.0122) was observed for the same vi

parameters during the finisher stage. Generally, birds gained more body weight during the finisher stage with increasing inclusion levels of NP in the diet as compared to the starter phase. The highest body weight gain was registered when birds were fed on a diet containing 0% NP (992.30g) and 25% NP (736.53g) for the starters and finishers respectively. This study thus concluded that substituting Fishmeal with Napier protein should be done for finisher diets at an inclusion level of 25% NP. Further studies should be conducted on Napier grass protein on other broiler chicken production parameters such as carcass quality, gut microbial environment, hematological components and others. As well, more crop-based protein sources need to be studied following the same procedures as this study to assess their potential in substituting the expensive and highly competitive fishmeal as a protein source in chicken production industry