Defatted black soldier fly larvae meal in lactating sow and pre-weaning piglet diets: impacts on growth performance, fecal microbiota, and metabolic pathways
To address the underexplored use of black soldier fly larval (BSFL) meal in pig farming for sustainable development, this study examined the effects of substituting conventional protein with defatted BSFL meal in the pre-weaning diet of piglets farrowed from sows fed defatted BSFL diets (0%, 2.3%, and 4.6%). Fifty-four piglets (18 piglets in each treatment) were housed with sows until 28 days of age and fed a pre-weaning diet containing 0%, 12.5%, or 25% defatted BSFL meal based on their respective sows' dietary treatments (0%, 2.3%, and 4.6% defatted BSFL diets) from 21 to 35 days of age. The growth performances and fecal microbiota of piglets were investigated. The results showed that sow diets and defatted BSFL meal-incorporated pre-weaning diets did not have a significant effect on the growth performance of piglets (P > 0.05). However, piglet growth tended to decrease with increasing defatted BSFL meals in the pre-weaning diets. Additionally, piglets nursed by sows fed defatted BSFL diets showed higher fecal short-chain fatty acid and lower ammonia levels at 21 days of age than those nursed by sows fed a control diet (P < 0.05). Furthermore, defatted BSFL meal-incorporated pre-starter diets decreased fecal amino acids and modified the gut microbial metabolic pathways associated with stress response. These findings suggest that the appropriate inclusion of defatted BSFL meal in the diets of lactating sows and piglets did not adversely affect the growth performance of piglets and may potentially improve the health of piglets at weaning; however, attention should be paid to the chitin content in BSFL diets, which may affect nutrient digestibility. Incorporating 2.3% defatted BSFL to sow and 12.5% to pre-weaning piglet diets may serve as a feeding strategy in pig farming. The results obtained will aid the application of BSFL meal in the swine industry and the study of its dietary effect on weaning stress in piglets.