Quillaja saponaria and/or Yucca schidigera ameliorate water quality, growth performance, blood health, intestine and gills histomorphology of Nile tilapia, Oreochromis niloticus

Abstract

This study aimed to evaluate the synergistic effects of Quillaja saponaria (QS) and Yucca schidigera (YS) on water quality, growth performance and health status of Nile tilapia. Fish (n = 120, 11.97 ± 0.497 g) were randomly distributed into four experimental groups in triplicates. (1) Control group (CG), fish received basal diet; (2) Yucca schidigera group (YS); fish received basal diet and 0.11 ml/m3 per week YS extract in water; (3) Quillaja saponaria group (QS), fish received basal diet supplemented with 300 mg/kg QS extract; (4) Mixed group (QS/YS), fish received basal diet supplemented with 300 mg/kg QS and 0.11 ml/m3 per week YS extract in water. Results revealed an improvement of water quality parameters in QS/YS, YS and QS compared with CG (p ≤ 0.05). Fish received QS and/or YS showed higher growth performance and lower feed conversion ratio than CG (p ≤ 0.05), with the best findings being reported in QS/YS. Using QS and/or YS improved gill health, increased intestinal villi length and goblet cell number compared with CG (p ≤ 0.05). Lymphocytes, total protein, globulin and lysozyme activity were increased, while cholesterol, triglycerides, glucose and creatinine were decreased in fish received QS and/or YS compared with CG (p ≤ 0.05), with the best results being observed in QS/YS. QS and/or YS supplementation increased lipase, amylase, superoxide dismutase, catalase while reduced malonaldehyde activity compared with CG, with the highest activity being recorded in QS/YS. Conclusively, Nile tilapia received QS and YS prompted synergistic effects that improved water quality, growth performance, immune-oxidative status, digestive enzymes, gills and intestine histomorphology.