Apparent total tract digestibility of calcium and phosphorus from partially defatted Hermetia illucens larvae meal in pigs

Insect meals, which have emerged as a sustainable protein source in animal nutrition, are also rich in calcium and phosphorus and thus might be a valuable source for supplying these minerals in farm animals. The aim of the present study was to determine the apparent total tract digestibility (ATTD) of these minerals from commercially available partially defatted meals of Hermetia illucens (HI) larvae in growing pigs. According to a difference approach, twenty male growing pigs with an average body weight of around 30 kg were divided into five groups of four pigs each and fed either a basal diet or the basal diet blended with one of three HI meals or monocalcium phosphate (MCP, as a positive control) for 14 days. Calcium and phosphorus ATTD were determined, by using the indicator method with acid-insoluble ash as an indigestible marker. Calcium ATTD on average of the three HI meals was 71.2%, ranging from 60.7% to 77.0%, and the ATTD of phosphorus was 80.6%, with a range of 70.8% to 88.9%. Calcium and phosphorus ATTD of MCP were 95.0% and 82.8%, respectively. The study shows that calcium and phosphorus from HI meals exhibit a relatively high ATTD in pigs, similar to that observed from inorganic mineral sources. Thus, HI meal could substantially contribute to the supply of calcium and phosphorus to pigs, thus opening the possibility to conserve scarce minerals resources such as phosphate-rich rocks for pig nutrition.