Partial Replacement of Spray-Dried Blood Plasma with Alternative Animal and Insect Protein in Weaned Pig Diets: Effects on Growth Performance, Digestibility, and Gut Health

This study was to evaluate the effects of partially replacing spray-dried blood plasma (SDP) with alternative insect- and animal-derived protein meals on growth performance, diarrhea incidence (DI), nutrient digestibility, intestinal responses, and oxidative status of weaned pigs. A total of 135 pigs (21 d of age; 6.56 ± 0.79 kg body weight [BW]) were assigned to five treatments for 20 d. The control diet contained 40 g/kg SDP, whereas the other diets contained 20 g/kg SDP plus 20 g/kg black soldier fly larval meal (BSF), fish meal (FM), pork crackling meal (PCM), or hydrolyzed chicken protein (HCP). HCP maintained growth and energy and crude protein utilization comparable to SDP. PCM reduced final BW and average daily gain (ADG; p < 0.05), while average daily feed intake tended to decrease (p = 0.084). BSF and FM reduced DI (p < 0.05). BSF showed the lowest energy and crude protein digestibility (p < 0.05), whereas FM reduced crude protein digestibility and tended to reduce jejunal PepT1 mRNA abundance (p = 0.052). BSF and PCM reduced jejunal TNF-α mRNA abundance, while FM and PCM reduced ZO1 mRNA abundance (p < 0.05). Overall, HCP showed the greatest potential to partially replace SDP while preserving growth performance and nutrient utilization.