Growth Performance and Nutritional Content of Tropical House Cricket (Gryllodes sigillatus (Walker, 1969)) Reared on Diets Formulated from Weeds and Agro By-Products.

Abstract

The tropical house cricket (Gryllodes sigillatus) can convert organic diets formulated from weeds and agro by-products into high-quality biomass. This study assessed the potential of diets developed from weeds and agro by-products as a feed source for G. sigillatus. We compared the development and nutritional value of crickets fed these alternative diets with control crickets fed chicken feed. Ten different diets with varying protein contents were used, including chicken feed (Control) with a protein content of 215 g/Kg dry matter (DM) basis), Cassava-Sugar Diet (250 g/Kg DM protein) Desmodium-Bran Diet (245 g/Kg DM protein), Morning Glory-Bean Diet (240 g/Kg DM protein), Morning Glory-Cassava Diet (235 g/Kg DM protein), Morning Glory-Cowpea Diet (225 g/Kg DM protein), Mixed Weed-Bran Diet (Optimal) (215 g/Kg DM protein) Cassava-Gallant Soldier Diet (200 g/Kg DM protein), Wheat-Bran Diet (145 g/Kg DM protein), and Maize-Cassava Diet (135 g/Kg DM protein). The weight and length of the crickets were measured for 9 weeks from day 1 after hatching to day 56. Then, the crickets were harvested and analyzed for dry matter, crude protein, fat, ash, fiber, minerals, and fatty acid composition. Cricket developmental time, survival rate, weight and length, yield, proximate components, and mineral and fatty acids differed depending on the diet provided. The Mixed Weed-Bran Diet (Optimal) resulted in the crickets developing faster (48.8 days), with a higher survival rate (88.1%), greater adult length (19.2 cm) and weight (0.44 g), and a nutrition content richer in minerals and unsaturated fatty acids when compared to other treatments. Oleic, linoleic, and palmitic acids were the major fatty acids. The highest protein content (64.4 g/100 g) was observed in the Mixed Weed-Bran Diet (Optimal) and Morning Glory-Cassava Diet treatments, while the Maize-Cassava Diet treatment crickets possessed the highest quantities of fats (19.1 g/100 g) and ash (15.4 g/100 g). The fatty acid profile of G. sigillatus revealed the cricket to have high unsaturated fatty acids except in crickets fed Morning Glory-Cowpea Diet and Wheat-Bran Diet. Generally, G. sigillatus grew best and had the most nutritious body composition on the Mixed Weed-Bran Diet (Optimal). The findings indicate that diets developed from weeds and agro by-products have great potential to be used as an alternative feed source for crickets and are capable of replacing expensive chicken feed, enhancing the circular farming potential of insect farming.