Evaluating the impact of bird manure vs. mammal manure on Hermetia illucens larvae

Abstract

Sound manure management plans enable limitation of manure accumulation, potential detrimental effects, and environmental pollution. Black soldier fly larvae play an important role in organic waste management for achieving a circular economy, sustainable development, and eco-friendly technology in developing countries. The present study evaluated the effects of bird manure vs. mammal manure as a substrate on the nutrient values of black soldier fly (BSF) larvae. Poultry and quail manure were used as bird manure, and goat and pig manure represented mammal manure. Quail manure and goat manure are new substrates for rearing BSF larvae. The percentages of water content, dry matter, total protein, total fat, fatty acids (FAs), and amino acids of different pre-pupae were analysed. The values of the essential amino acid index (EAAI) of pre-pupae were calculated to match the requirements of meat-type and laying hens, growing and breeding quail, growing pigs (20–50 kg), shrimp, fish and brood-stock Atlantic salmon compared with fish meal and soybean meal. The results indicated that the pre-pupae that fed on bird manure had higher body weights than mammal manure. The pre-pupae of pig manure took the longest to develop (36 days), and the pre-pupae of poultry manure and goat manure required the same development time (26 days). Thirty days were needed for pre-pupae to grow on quail manure. The percentages of total fat and dry matter were higher in the pre-pupae of bird manure (31.62 ± 1.53% and 35.04 ± 1.44%, respectively), and the percentage of the water content of pre-pupae was higher using mammal manure as a substrate (69.04 ± 2.11%). There were no significant differences in total protein between the pre-pupae (ranged from 39.88 ± 0.58% to 42.81 ± 1.17%). The percentages of saturated and polyunsaturated FAs were increased in pre-pupae of quail manure and poultry manure (69.70 ± 1.77%, 10.37 ± 0.42%; respectively), and the pre-pupae of pig manure recorded the highest value of monounsaturated FAs (35.52 ± 1.84%). All the pre-pupae had an ideal amino acid profile for the requirement of feeding different animals, and these values were higher than fish-meal and soybean meal. The nutritional values of BSF larvae reared on bird manure were better than larvae reared on mammal manure. The economic benefits of manure to feed BSF larvae will alleviate the increasing pressure on animal feed, which makes the production of BSF a realized revenue for economical industrial waste management.