Performance, nutrient digestibility and selected gut health parameters of broilers fed with black soldier fly, lesser mealworm and yellow mealworm

Abstract

This study aimed to investigate the effect of feeding three types of insect meal on broilers’ performance and selected gut health parameters. Day-old straight-run Ross 308 broilers (n=600) were group housed in 24 pens and fed diets containing 10% of either Tenebrio molitor (yellow mealworm, YMW), defatted Hermetia illucens (black soldier fly, BSF) or Alphitobius diaperinus (lesser mealworm, LMW), or a control (CTRL) diet for 35 days. Feed intake and gain were recorded at days 14, 28 and 35. On day 13, four broilers from each pen were placed in metabolic cages to determine apparent total tract digestibility after adaptation to 100% of one of three types of insect meal. Birds were killed, and intestinal content was collected on days 22 and 36 for determination of pH, selected groups of intestinal bacteria and short chain fatty acids (SCFA). Footpad lesions were scored on day 36. Birds fed LMW and YMW ate less than birds fed BSF or CTRL, but feed conversion ratio (FCR) was improved when birds were fed LMW. Dry matter digestibility was similar among insects, but differences were observed in ash and fat digestibility and nitrogen retention in which the BSF meal gave the highest digestibility of these nutrients. Birds fed any type of insect meal diet had higher levels of Clostridium perfringens in caecal and ileal digesta. Footpad dermatitis severity was similar between CTRL and insect-supplemented diets. Total SCFA levels as well as butyrate in digesta of birds fed BSF was lower than the levels of these SCFA in the other treatments. The propionate concentrations in caecal and ileal digesta were high for all diets containing insect meal. In conclusion, gain was maintained when feeding BSF but not LMW and YMW due to lower feed intake. Insect meal did not affect indicators of broilers’ gut health.