Effect of substituting fish meal (Rastrineobola argentea) protein with black soldier fly (Hermatia illucens) larvae meal protein on performance of broiler chickens

Abstract

The study aimed at determining level at which Black Soldier Fly Larvae Meal Protein (BSFLMP) can optimally substitute Fish Meal Protein (FMP) in broiler chicken diets and the effect of this substitution on meat quality, gut integrity and microbiology, immune response, and marginal benefits. Three experiments were conducted, each in a completely randomized design. In each experiment a starter and finisher diet were fed for 28 and 14 days, respectively. In the first experiment, chickens were fed on starter diets with varying levels of BSFLMP; 0% (control), 25%, 50% 75% and 100%, and finished on a conventional diet (no BSFLMP). In the second experiment, birds were started on a conventional diet and finished on diets containing varying levels of BSFLMP as indicated above. In both experiments the optimal level of BSFLMP inclusion was determined by measuring weight gain, feed intake, feed utilization efficiency. In addition, meat quality, and the marginal benefits of feeding BSFLMP were evaluated. In the third experiment, the optimum substitution levels obtained in the first two experiments were evaluated against a conventional diet for their effects on gut integrity and bacterial quantity, and immune response. Results from the first two experiments indicated that increasing the level of BSFLMP beyond 50% in the starter and 75% in finisher diets reduced (p<0.05) feed consumption, body weight gain and feed utilization efficiency. Chickens which showed impaired growth when fed starter diets with BSFLMP levels beyond 50% exhibited compensatory growth when finished on a conventional diet. Increasing the level of BSFLMP beyond affected meat quality by reducing (p<0.05) n-3 fatty acids and the crude protein content and increasing (p<0.05) crude fat and n-6 fatty acids, but had no effect on blood cholesterol and triglycerides. The determined optimum substitution level of BSFLMP for FMP was 54% in the starter and 76% in finisher diets. Feeding optimal levels of BSFLMP reduced villi height, increased hind gut microbes and improved the humoral immune response of broiler chickens. Increasing the level of BSFLMP in feed reduced cost of feed and increased marginal net benefits up to the determined optimal levels. In conclusion, BSFLMP can economically substitute FM in both starter and finisher diets at levels not exceeding 54% and 76%, respectively without compromising performance.