Replacing soybean meal with black soldier fly larvae meal or fishmeal: impacts on broiler growth performance and, Cecal MAO and COMT enzyme activities

Authors: Wickramasuriya, Samiru; Lyte, Joshua

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/8/2025
Publication Date: 1/26/2026
Citation: Wickramasuriya, S.S., Lyte, J.M. 2026. Replacing soybean meal with black soldier fly larvae meal or fishmeal: impacts on broiler growth performance and, Cecal MAO and COMT enzyme activities. Meeting Abstract. International Poultry Scientific Forum, Atlanta, Georgia. January 26-27, 2026.

Interpretive Summary:

Technical Abstract: Despite the numerous studies that have evaluated how alternative protein sources influence broiler growth, far less is known about how these dietary proteins affect neurochemical pathways within the intestinal tract during early development. Considering enteric neurochemicals contribute to a wide range of production-relevant functions including growth, health, behavior, and food safety, clarifying how different protein ingredients shape gut neurochemical profiles is essential. Thus, the present study examined whether partial replacement of soybean meal with black soldier fly larvae meal (BSFLM) or fishmeal (FM) alters growth performance and the quantitative abundance of cecal monoamine oxidase (MAO-A and MAO-B) and catechol-O-methyltransferase (COMT) in chickens at 4 days of age. Experimental design: Male, day-old by-product breeder chicks were randomly assigned to three dietary treatments containing soybean meal (SBM), BSFLM, or FM. Chicks were housed in floor pens and managed under standard, age-appropriate conditions. Body weights were recorded, and cecal samples were collected from six birds per treatment group at 4 days of age. A protease inhibitor cocktail was first added to the tissues, which were then homogenized and supernatant collected. Total protein was quantified using the Bradford assay. A series of commercially available primary antibodies were first tested and validated for use in chickens using intestinal and positive control tissues, including chicken brain regions. Target protein quantification was performed in cecal tissue lysates to assess abundances of MAO-A, MAO-B, and COMT. The cecal protein lysate samples were then diluted and analyzed using the Jess capillary immunoassay system with the Jess Separation module, incorporating a fluorescent standard, as per the manufacturer's instructions. Protein normalization was performed following manufacturer guidelines. Statement of statistical analyses: All data were analyzed using one-way ANOVA followed by Tukey’s post-hoc. Statistical significance was set at p<0.05. Results: At 4 days of age, body weight did not differ among chicks fed the three dietary treatments (p > 0.05). Chickens fed with the SBM diet exhibited significantly higher MAO-A levels than those fed the FM diet (p < 0.05), while MAO-A expression did not differ between the SBM and BSFLM treatments (p > 0.05). MAO-B levels were similar across all dietary treatments (p > 0.05). Membrane-bound COMT expression was higher than soluble COMT activity in all groups; however, no differences in COMT expression were detected among the three protein-source treatments. Conclusions: Partial replacement of soybean meal with black soldier fly larvae meal did not influence growth or the activity of cecal monoamine oxidase or catechol-O-methyltransferase in broilers by 4 days of age. Additional studies are underway evaluating long term impact of these dietary formulations on bodyweight and intestinal neurochemistry at ages following 4 days of age.