Acceptance, tolerance and apparent nutrient digestibility of complete diets based on larvae meal of Hermetia illucens in cats

Abstract

Insect meal can be used as a component of cat food for several reasons. In addition to veterinary indications, particularly for animals suffering from food allergy, economic or ecological reasons might be relevant. Because no data in cats are available on the acceptance, tolerance or nutrient digestibility of a diet based on insect protein, it was the aim of the present study to evaluate these aspects more closely. Ten healthy, adult cats received two different diets (A, B) based on larvae meal of the black soldier fly (Hermetia illucens) for 6 weeks each. At the end of each feeding period, the faeces of the cats were collected and analysed. Both diets contained titanium dioxide as an indigestible marker to calculate the apparent nutrient digestibilities. The results demonstrated a generally good food tolerance and acceptance. However, one cat displayed emesis after the ingestion of diet A and subsequently refused the diet, thus this animal was removed from the study. With regard to diet B, no emesis of the cats was observed. However, three cats displayed a low feed intake or refused the diet, thus these cats were also removed from the study. The calculation of the apparent nutrient digestibilities revealed a high crude fat digestibility (96.0 ± 1.26 % for diet A and 92.7 ± 1.53 % for diet B). However, the apparent digestibility of crude protein (77.0 ± 3.48 % and 73.4 ± 3.73 % for diets A and B, respectively) and of the specific amino acids was only moderate. Both diets based on larvae meal of Hermetia illucens were generally tolerated by most of the cats. However, individual differences were also present. Because the apparent crude protein digestibility was only moderate, it is recommended to consider an adequate safety margin when formulating diets based on insect protein to prevent nutrient deficiencies.