The effects of partially replacing animal protein sources with full fat black soldier fly larvae meal (Hermetia illucens) in nursery diets on growth performance, gut morphology, and immune response of pigs

Abstract

One hundred and forty-four newly weaned pigs (6.74 ± 0.23 kg initial BW; 21 days of age) were used to determine the effect of partially replacing animal protein sources with black solider fly larvae meal (BSFLM) in nursery diets on growth performance, gut morphology, and immune response. After weaning, pigs were placed in 24 pens (6 pigs per pen) and pens were randomly assigned to one of four dietary treatments (study d 0; n = 6), which were fed over 3 phases (phases I, II, and III were fed for 7, 14, and 21 days, respectively). Two nursery diets were formulated with 25% (LowFF) and 50% (HighFF) of the animal protein sources replaced by full fat BSFLM. Conventional nursery diets including animal protein sources without (CON-) and with antibiotics (220 mg Aureomycin per kg of complete feed; CON+) served as controls. On day 8, two pigs per pen were sacrificed to collect organ weights and for intestinal histomorphological measurements. On days 9 and 23, two pigs per pen were vaccinated with the novel antigen ovalbumin (OVA). Blood samples were collected on days 9, 23, and 38 to assess concentrations of plasma haptoglobin and OVA-specific immunoglobulins G (IgG) and IgG1. On day 38, the same two pigs per pen underwent a dermal hypersensitivity test and skin-fold thickness was measured at 0, 6, 24, and 48 h post-intradermal injection with OVA. Pigs fed the CON- had greater ADFI and lower G:F in phase 2 versus those fed CON+ and HighFF diets (P < 0.05 and P < 0.05); intermediate ADFI was observed for pigs fed the LowFF diet. Overall in the nursery period, ADG (496 ± 13 g), ADFI (743 ± 23 g), G:F, and final BW (27.61 ± 0.66 kg) were not different among dietary treatments. There were no differences in organ weights, jejunal or ileal villus heights, or crypt depths among dietary treatments. There were no differences in OVA-specific IgG, IgG1, or plasma haptoglobin among dietary treatments at any of the blood sampling times. Although not different, pigs fed the LowFF, HighFF, and CON+ diets had respectively 2.0, 1.7, and 1.4× greater dermal hypersensitivity response to OVA versus those fed CON-. Both inclusion levels of BSFLM in nursery diets supported growth performance, gut morphology, and indices of immune function not different from the CON+, which suggest that full fat BSFLM can replace at least 50% of animal protein sources in nursery diets of pigs without any deleterious effects on pig growth.

The effect of deoxynivalenol-contaminated corn and an immune-modulating feed additive on growth performance and immune response of nursery pigs fed corn- and soybean meal-based diets

“…With respect to humoral immunity, OVA-specific IgG were detected in all pigs that were vaccinated with OVA, with an expected greater response observed on day 38 than on day 25. This indicated that the immunization protocol was efficacious; other researchers have also used a similar protocol in pigs ( Crawley et al, 2005 ; Huber et al, 2018 ; Crosbie et al, 2021 ). Previous research demonstrated that DON contamination can compromise the immune responses in nursery pigs ( Bondy and Pestka, 2000 ; Pestka et al, 2004 ; Cheng et al, 2006 ), but DON contamination can also have an immunostimulatory effect, depending on concentration and exposure duration ( Bondy and Pestka, 2000 ).…”

Insect as feed ingredients for pigs

“…Weaning [36] Growing [37] North America Canada BSF larvae (Hermetia illucens) Weaning [39] BSF larvae (Hermetia illucens) Growing [38] BSF, black soldier fly; HF, house fly.…”

“…In weaning pigs, 50% of animal proteins, including fish meal, spray-dried blood meal, and blood plasma replaced with full-fat BSF larvae meal (d 0 to 7: 14.76%, d 7 to 21: 7.5%, d 21 to 42: 1%) had no impact on the final body weight (BW, d 42) and average daily gain (ADG) for the overall period (d 0 to 42) of weaned pigs, whereas it improved gain to feed (G:F) ratio for d 7 to 21 by 12% without any effects on weights of liver and gastrointestinal tract and histomorphology for jejunum and ileum at 8 d postweaning [39]. Inclusion of partially defatted BSF larvae meal at 10% to replace SBM increased average daily feed intake (ADFI) of weaned pigs for d 24 to 61 due to increased diet palatability [32].…”

“…The full-fat BSF larvae meal was used for feeding trial study with growth performance and immune response of weaned pigs [ 38 ]. The full-fat BSF larvae meal and defatted BSF larvae meal were used for evaluating the standardized ileal digestibility (SID) in growing pigs [ 39 ]. Unfortunately, it was hard to find any published articles or data from Latin American countries conducting swine research with those insect species (BSF, HF, and mealworm).…”

Assessing the Effectiveness of Providing Live Black Soldier Fly Larvae (Hermetia illucens) to Ease the Weaning Transition of Piglets

“…Some observed benefits of BSFL inclusion (in different amounts of full-fat or defatted meal) in weaner pig diets are increased growth, increased beneficial bacteria in the gut, and increased villus height in the jejunum (43)(44)(45). In other cases, however, BSFL meal inclusion did not affect weaner pig performance (43,46). In our previous study, piglets that were provided with small amounts of live BSFL for 11 days after weaning showed high levels of larvae-directed exploration, decreased levels of pig-directed oral manipulation and fighting, and decreased neophobic responses toward an unfamiliar object (41).…”