Improving egg quality in laying hens using calcium salt of black soldier fly larvae oil

Abstract Black soldier fly larvae (BSFL) oil has gained attention as a potential substitute for vegetable oil in feed formulations designed to improve productivity and product quality. This study aimed to investigate the impact of supplementation BSFL oil calcium salt (BSFLO-SCa) on the egg quality and gene expression involved in fat metabolism in laying hens. A total of sixty 40-wk-old ISA Brown laying hens were divided into three distinct groups: a control group (T0) that received a basic diet, and two treatment groups that were supplemented with 1% (T1) and 2% (T2) BSFLO-SCa. Each group consisted of 5 replicates, with 4 laying hens per replicate. The study indicated that the inclusion of 2% of BSFLO-SCa significantly increased egg albumen weight, height, ratio, eggshell weight, and thickness ( ). The inclusion of 1 and 2% of BSFLO-SCa increased the yolk lightness (L*) and yellowness (b*), but redness (a*) was decreased ( ). Moreover, BSFLO-SCa supplementation with 1 and 2% reduced ( ) egg fat and cholesterol. Analysis of fatty acid profiles showed significantly increased medium-chain fatty acid (MCFA) and polyunsaturated fatty acid (PUFA) ( ), while monosaturated fatty acid (MUFA) reduced ( ) with 2% BSFLO-SCa. Gene expression related to lipid metabolism, such as fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC), as well as cholesterol synthesis gene expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) were downregulated ( ). In conclusion, the inclusion of 2% BSFLO-SCa in the diet improved quality and reduced fat and cholesterol content in eggs from laying hens. This improvement was accompanied by downregulation of key genes involved in lipid metabolism.