Abstract:
The African poultry industry is characterized by high feed prices due to the limited availability of sufficient, high-quality protein. This has led to significant shortages, driving up the costs of poultry products and stagnating the sector's growth. Protein is the most expensive component of poultry feed, and its quality and availability are the limiting factors. This study investigated the effects of black soldier fly (Hermetia illucens L.) larvae meal (BSFLM) on growth performance, profitability and gene expression in 200 Ross 308 broiler chickens. Soybean meal (SBM) and fishmeal (FM) were substituted with varying levels of the BSFLM, resulting in five dietary treatments: SBM only, FM only, FM + BSFLM (1:1), SBM + BSFLM (1:1), or BSFLM only. Growth rates, organ weights, immune genes; interleukin-2 (IL-2), interleukin-6 (IL-6), tumor necrotic factor alpha (TNF-α), interferon-gamma (IFN-γ) and growth-related genes; chicken growth hormone (cGH), insulin growth factor 1 (IGF-1) expression were measured by quantitative Polymerase chain reaction (qPCR). Our results demonstrate that birds fed FM+BSFLM had significantly higher final body weight (p < 0.001), average daily weight gain (p < 0.001), and a low feed conversion ratio (p < 0.001). Birds fed FM+ BSFLM had significantly higher carcass weight (p = 0.026), while those fed SBM only yielded the lowest carcass weight. There were no significant differences in all the profitability parameters across the five treatments. The IL-2, IL-6, TNF-α, IFN-γ, IGF-1 and cGH gene expressions were significantly upregulated in the liver and spleen of birds fed diets containing BSFLM. Growth-related genes (cGH) positively correlated with live weight, body weight gain, and ADG. In conclusion, BSFLM at partial inclusion levels enhances broiler growth without significantly affecting profitability. Additionally, the inclusion of BSFLM in broiler diets upregulates the expression of genes associated with growth and immunity, leading to improved productivity in broiler production. It is recommended to use BSFLM as a partial replacement for soybean and fishmeal to improve growth and immune gene expression in broiler chickens.
Keywords: black soldier fly larvae meal, profitability, immune modulation, gene expression, and poultry nutrition.
