Assessing Nursery-Finishing Pig Manures on Growth of Black Soldier Fly Larvae

Simple Summary With the increasing consumption of pork, pig manure has become an important pollution problem in the pig livestock industry. It is worth noting that the amount of manure from fattening pigs far exceeds that from breeding herds. During the fattening period, the manure's composition may vary depending on the stage of the pig's growth, from nursery to finishing, and on the variety of feed. The treatment of manure by black soldier fly larvae (BSFL), Hermetia illucens (L.), (Diptera: Stratiomydiae) is an emerging waste management technology. Although studies have shown that BSFL could be used in swine manure treatment, there is little literature discussing the nutrient discrepancies of swine manure types and their influences on BSFL growth. Thus, this study analyzed the nutrient composition of different fattening pig manure types. Furthermore, the factors that influence larval growth were identified. This could be used in further waste treatment and formulation diets for BSFL. Livestock manure is an important component of agricultural organic waste, and in recent years, with the development of research on the bioconversion of manure, BSFs have been proven to be useful in the treatment of a variety of livestock wastes. In-depth research on the composition of manure and its effect on the development of BSFL is, however, very scarce. The purpose of this study was to identify the parameters that influenced the growth of BSFL that was fed fattening pig manure. The pH, moisture, and nutrients of the fattening manures (namely, nursery, growing, and finishing pig manures) were measured. To examine the influence of manure types on larval growth, 100 larvae were inoculated in 100 g of each type of manure in triplicate. According to the findings, larvae fed finishing pig manure had the lowest dry weight (30.2 +/- 6.1 mg) compared to those fed growing (58.2 +/- 7.3 mg) or nursery (65.5 +/- 6.2 mg) pig manure. The correlation coefficients (r) between the nutrients in the manure and the weight of the larvae were calculated. Hemicellulose had the greatest |r| value (0.9569). Further research revealed that larvae raised on hemicellulase-pretreated finishing pig manure frequently weighed 21-30% (days 2-8) more than larvae raised on control manure. In conclusion, hemicellulose was a significant component that might hinder larval growth. The results of this study could be used to improve the system before it is put into use.