Digestibility of insect meals for dogs and their effects on blood parameters, faecal characteristics, volatile fatty acids, and gut microbiota

Abstract

To evaluate the effects of the inclusion of three insect meals in dogs’ diets (Madagascar cockroach, MC; cinerea cockroach, CC; and superworm, SW) at two different levels (7.5 and 15%) on nutrients digestibility, blood parameters, faecal characteristics, volatile fatty acids, and gut microbiota, a digestibility trial was performed in a 3×2 factorial scheme in Latin square design 6×6. Experimental diets consisted of insect meals replacing the reference diet (dry and moist commercial feeds) on each of the two levels. Apparent metabolised energy of dry matter (AMEDM) was higher for dogs fed with SW than MC meal in both inclusion levels and, with CC meal at 7.5% of inclusion. The digestibility for dry and organic matter and protein was higher for dogs fed with SW than for MC meals. The faecal pH was lower for the dogs fed with CC than for the MC meal. Butyrate was higher for dogs fed with CC than MC and SW meals. Phenol was higher for dogs fed with MC than SW meal. The relative abundance of the phyla Proteobacteria and the genus Sutterella were higher at 7.5% of inclusion than 15%. Dogs fed with SW meal had a greater abundance of Prevotella, Faecalibacterium, and an unidentified genus in the family Ruminococcaceae than dogs fed with MC meal. The abundance of Allobaculum was higher for dogs fed with SW meal than CC meal. Even though all the insect meals evaluated can be included in adult dogs’ diets, the superworm meal appears as a highly digestible ingredient for dogs with lower negative impacts on intestine fermentative products and microbiota profile.