The researchers saw that using BSF to replace 25% of SBM in diets could improve digestive parameters, immune function, and intestinal microbiota, and thus improve growth performance of piglets. However, they said using BSF to fully substitute SBM in the piglets’ diets showed an adverse effect on piglet performance citing as a possible reason the fact that piglets cannot secret enough chitin degrading enzyme.
“Piglets might have the ability to degrade chitin to release the nutrients encapsulated by chitin and produce chito-oligosaccharides as prebiotics to improve health status.
“The chitin content in diets of the BSF100 group might be too high for piglets to degrade and utilize, which may explain why piglets from the BSF100 group showed poor performance,” noted the authors in a paper published in Animal Nutrition.
The scientists said they wanted to fully assess the effects of BSF on piglet performance and provide new knowledge on the application of BSF in pig diets.
They set about exploring the impact of varying degrees of BSF meal supplementation on weaned piglet growth performance, appetite hormones, digestive enzyme activities, the level of chitin-degrading enzyme and tight junction proteins, intestinal morphology, and microbiota.
A total of 180 Duroc × Landrace × Yorkshire piglets were allocated to one of five. The piglets were raised on plastic slatted floors. Pens were also equipped with duckbill drinkers and adjustable feeders, and the animals had ad libitum access to feed and water. The humidity and temperature in the room were automatically kept at about 70% and 25 °C, respectively, explained the research team.
Full-fat BSF with a crude protein (CP) level of 36.69% was used in the trial.
A corn-soybean basal diet (BSF0) was formulated, and BSF was used to replace 25% (BSF25), 50% (BSF50), 75% (BSF75), or 100% (BSF100) of the protein provided by SBM.
The findings show that average daily gain (ADG) and average daily feed intake (ADFI) of piglets changed quadratically with the increase of the ratio of BSF replacing SBM in diets, said the authors.
Compared with BSF0, BSF25 significantly increased ADG of piglets, and this result was consistent with previous work, they added. The scientists also reported that the improved ADG of piglets might be due to the increase of ADFI, and insect meal has been thought to increase diet palatability.
In comparison with BSF0, piglets from the BSF25 group showed a higher duodenal ratio of villus height to crypt depth, increased jejunal sucrase activity, serum neuropeptide Y and ghrelin levels, elevated ileal immunoglobulin (Ig) A, IgG and IgM contents and a lower leptin level, and piglets from the BSF100 group exhibited an increased relative weight of kidney, they observed.
However, no significant differences were observed in the expression level of tight junction proteins and chitin-degrading enzyme, said the researchers.
Additionally, compared with BSF0, they saw that the abundance of short chain fatty acid producing bacteria such as Ruminococcaceae, Faecalibacterium and Butyricicoccus increased, and potential pathogenic bacteria decreased in piglets from the BSF25 group, whereas piglets from the BSF100 group had a greater abundance of harmful bacteria.
Source: Animal Nutrition
Title: Endogenous chitinase might lead to differences in growth performance and intestinal health of piglets fed different levels of black soldier fly larva meal
Authors: D Li et al