Egg fatty acid profiles and potential health risk from defatted insect meal in laying hens’ diets

Abstract

Insects, a staple feed for wild birds and free ranging poultry, have a relatively high protein quality and are a promising feed for commercial poultry. Replacing soybean meal with insect derived feeds potentially reduces dependency on feed imports, increasing the sustainability of egg production – but only if maintaining or enhancing their nutritional quality. This study investigated egg fatty acid (FA) profiles from replacing soyabean meal with Hermetia illucens (black soldier fly) meal (HIM) for laying hens. A three-week trial with 30 organic Lohman Selected Leghorn hens between 64-74 weeks old was repeated with four flocks at the end of their first laying cycle. In all replicate trials, ten birds were randomly allocated to each of three diets: (1) control with 360 g soybean/kg and no HIM; (2) H12 with 120 g HIM and 156 g soybean/kg; and (3) H24 with 240 g HIM/kg and no soybean. Complete replacement of soya (H24) increased saturated fatty acid (SFA) and monounsaturated fatty acids (MUFA) and decreased total polyunsaturated fatty acids (PUFA), omega-6 (n-6) and omega-3 (n-3) PUFA concentrations in eggs. The intermediate H12 diet (replacing 33% soya) gave similar n-3 and MUFA concentrations to control eggs but significantly increased SFA and reduced total PUFA. However, birds moderated the transfer of high intakes of potentially damaging C12:0 and C14:0 into eggs and although differences in eggs were highly significant and great (relative to very low levels in control eggs) concentrations were substantially lower than in insect meal itself and some commonly consumed foods.