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

Black soldier fly larvae (BSFL) oil has garnered interest as potential substitute for vegetable oil in feed formulations aimed at enhancing 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 inclusion 2% of BSFLO-SCa significantly increased egg albumen weight, height and ratio, eggshell weight, and thickness (P < 0.05). The inclusion 1 and 2% of BSFLO-SCa increased the yolk lightness (L*) and yellowness (b*), but redness (a*) was decreased (P < 0.05). Moreover, BSFLO-SCa supplementation with 1 and 2% reduced (P < 0.05) egg fat and cholesterol. Analysis fatty acid profiles showed significant increased medium chain fatty acid (MCFA) and polyunsaturated fatty acid (PUFA) (P < 0.05), while monosaturated fatty acid (MUFA) reduced (P < 0.05) 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 (P < 0.05). In conclusion, inclusion at 2% of BSFLO-SCa in diet improved the egg quality and reduced fat and cholesterol egg of laying hens. This improvement was accompanied by downregulation of key genes involved in lipid metabolism.