Effects of dietary Khejri, Prosopis cineraria pod and seed extracts on the growth performance, digestive enzyme activities and body composition of Labeo rohita fingerlings

Two consecutive 60-day feeding experiments were conducted to evaluate the effects of incorporating Khejri pod and seed extract into the diet on the growth, nutrient utilization, and digestive enzyme activities of rohu (Labeo rohita) fingerlings. In initial screenings, ethanolic extracts from Khejri pod and seed meal showed outstanding antioxidant properties measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and total phenolic content (TPC) assays, along with notable antibacterial effects against Edwardsiella tarda and Aeromonas hydrophila. Iso-nitrogenous and iso-caloric diets were formulated for both experiments. In the first experiment, diets were enriched with varying levels of ethanolic Khejri pod extract (KPE; 0, 5, 10, and 20 g kg−1), while the second experiment included ethanolic Khejri seed extract (KSE; 0, 5, 10, and 20 g kg−1). In both experiments fish fed diets with 5 g kg−1 of either KPE or KSE exhibited superior growth rates, feed conversion efficiencies, and apparent net protein utilization (P < 0.05). Among digestive enzymes, protease and lipase activities were found to positively correlate with the growth performance of rohu fingerlings (P < 0.05), while amylase activities showed an inverse relationship with dietary levels of KPE and KSE (P < 0.05). With the exception of crude lipid content, no significant differences in whole-body composition were observed between control and dietary treatment groups (P > 0.05). In conclusion, supplementation with 5 g kg−1 ethanolic Khejri pod or seed extract proves to be an effective growth promoter, augmenting the growth performance and digestive enzyme activities of rohu (L. rohita) fingerlings.