Insects represent a sustainable protein source with high nutritional value that can be used in pig’s diet. The aim of this study was to evaluate the effects of the inclusion of Tenebrio molitor larvae meal, as a partial replacement for soy protein concentrate, on performance, diet digestibility, and modulation of gut microbiota in growing pigs. A total of 14 growing pigs (80 ± 2 days of age) were randomly divided into two groups (7 animals/box) for 28 days: the control group (CTRL) received a complete and balanced diet consisting of a complementary formula (95%) supplemented with 4% fermented soy protein concentrate and 1% soybean oil; the treatment group (TRT) was fed with the same complementary formula supplemented with 5% T. molitor larvae meal in replacement of fermented soy protein concentrate and soybean oil.
Animals were weighed weekly and fecal and blood samples were collected for evaluation of nitrogen digestibility and serum metabolic profile by enzymatic chemical and colorimetric analysis, respectively. Microbial DNA was extracted from rectal swabs to evaluate the gut microbiota by 16S rRNA gene amplification and sequencing. No differences were observed in growth, feed efficiency and diet digestibility for protein and lipid components during the trial. Comparable results between the two groups were observed for serum concentrations of albumin, globulin, urea and interleukin-6, suggesting a good health status of pigs. The TRT group showed an increase in beta diversity index after 28 days of trial, suggesting a modulation of the fecal microbiota induced by the inclusion of T. molitor (p < 0.05). These results suggest that 5% T. molitor meal can be successfully used as a partial replacement of soy protein concentrate in the diet of growing pigs.