Exploring the potential of cotton leafworm (Spodoptera litura) as a sustainable and efficient alternative protein source in broiler feed
In recent times, poultry nutritionists have shown increased interest in incorporating insect meal as an alternative source to fulfil the protein needs of poultry, driven by sustainability issues related to conventional protein sources like soybean meal and fish meal. The present study shows the effects of replacing 4, 8 and 12% soybean meal (SBM) with cotton leaf worm (Spodoptera litura) on growth performance, blood haematology, intestinal histomorphology and meat quality of Ross 308 broiler. We also evaluated commercially available black soldier fly (Hermetia illucens) larvae for comparison. A total of 350 one-day-old chicks were randomly divided into seven dietary treatments (5 pens/treatment and 10 birds/pen). The results showed that the broiler fed on 12% S. litura or H. illucens had notably (P < 0.05) higher live weight, average daily weight gain and better feed conversion ratios. The diets containing 12% S. litura or H. illucens significantly (P < 0.05) improved broiler blood haematology (haemoglobin, red blood cells, haematocrits, mean corpuscular volume, lymphocytes, heterophils, platelets and total leucocytes as well as serum bio-chemistry traits i.e. total protein and globulin) and gut histology (villus height (Vh), crypt depth (Cd), villus width (Vw), and Vh/Cd ratios). The broiler fed on a 12% S. litura or H. illucens diet indicated a higher L* (lightness) and b* (yellowness). It was concluded that replacing soybean meal up to 12% with either S. litura or H. illucens improves the growth performance, blood haematology, gut histomorphology, and meat quality traits of broiler and thus can be used as an alternate source of protein in broiler feed.