Apparent faecal digestibility and nitrogen retention in piglets fed whole and peeled Cambodian field cricket meal

Abstract

This study evaluated diets including whole or peeled (legs removed) crickets (Teleogryllus testaceus) in terms of diet digestibility, growth and nitrogen retention, using pigs as an animal model. The experiment included three iso-nitrogenous diets (18.4% crude protein) including either whole cricket meal (WC), body cricket meal (legs removed, BC) or fish meal (control) as the main protein source. Castrated male piglets (n=21, 30-45 days) with initial body weight 13.0±0.3 kg were allocated to one of the dietary treatments (7 piglets/treatment) in a fixed block design. The piglets were kept in single bamboo/wooden stalls with slatted floors and were adapted to the feeds and the housing for 5 days before starting the 25-day experiment. The diets were offered ad libitum, but close to appetite (approximately 5% of body weight). Feed intake was recorded and piglets were weighed every 5 days. During days 20-25, total collection of faeces and urine was performed. Dry matter and nutrient intake were higher for piglets fed the WC and BC diets than for those fed the control diet. From day 10, piglets fed BC and WC were heavier than piglets fed the control diet, but there were no differences between WC and BC. Dry matter digestibility was highest for diet WC, and ash, crude fibre and crude fat digestibility was higher for BC and WC than for the control diet. Feed conversion ratio was lower for the WC and BC diets than for the control diet, and nitrogen retention (% of digested) was higher. We concluded that field cricket meal is a nutritious feedstuff for mono-gastric animals, and most likely also for humans. Removal of legs did not facilitate or improve the digestibility values and nitrogen retention. Thus, in order to minimise food waste, crickets should not be peeled in this way if they are going to be processed into meal.