Effects of Partial Replacement of Soybean Meal with Defatted Hermetia illucens Meal in the Diet of Laying Hens on Performance, Dietary Egg Quality, and Serum Biochemical and Redox Indices

Abstract

This study was carried out on 96 caged Bovans Brown laying hens at an initial age of 25 weeks, which were randomly assigned to four experimental groups of 12 replicates (cages) of two hens per cage. The control group hens received a diet containing 20% soybean meal (SBM), without Hermetia illucens larvae meal (HIM) content. The hens in the experimental groups received a diet containing defatted HIM at levels of 5, 10, and 15% (HIM 5%, HIM 10%, and HIM 15%, respectively), at the expense of a proportionally decreasing content of SBM. During the 12-week experiment, the laying performance, biochemical and redox blood indices, and liver condition were examined. The cholesterol level, fatty acid profile, and malondialdehyde content in egg yolks were also evaluated to determine the dietary quality of the eggs. The inclusion of HIM at any level in the diet did not affect the laying performance parameters (p > 0.05). Increased serum Ca and uric acid contents were observed. There was no effect on the redox indices in plasma. The number of hepatocytes was decreased in the HIM-fed groups. The level of cholesterol in yolks was reduced, and the fatty acid profile showed significant changes. Despite the high lauric acid content in the H. illucens meal, it was present in trace amounts in yolks. In the HIM-fed groups, the levels of saturated fatty acids increased significantly, whereas those of unsaturated fatty acids decreased in the yolks in the same groups.