Feeding of Nile tilapia Oreochromis niloticus and white shrimp Litopenaeus vannamei with different diets supplemented with Yucca schidigera and Quillaja saponaria extracts (saponins).

摘要

Yucca (Yucca schidigera) and Soapbark (Quillaja saponaria), both native desert plants, are major commercial sources of saponin extracts. Yucca schidigera is native to the southwestern United States and to the arid Mexican desert, and Quillaja saponaria is found in arid areas of Chile. Saponins have detergent or surfactant properties with both water-soluble and fat-soluble components.;The use of natural saponins from yucca and soapbark as an additive in the diet, has improved production in aquatic organisms. The purpose of this study was to evaluate the effect of inclusion of Nutrafito plus (NTF+), which is a mixture of Yucca and Soapbark extracts, on growth, survival, and development of Nile tilapia Oreochromis niloticus and the effect on growth, survival, development, and digestive enzyme activities for juvenile Pacific white shrimp Litopenaeus vannamei.;The extracts were included at different levels in the diets of tilapia and shrimp in four experiments. In experiment 1, at the end of 6 weeks there was no significant difference (p > 0.05) between growth rates of tilapia fed 6 different diets, with no mortality nor abnormal behavior in any of the treatments. Water quality parameters were determined weekly and remained within recommended limits for Nile tilapia culture.;In the second trial, at the end of 40 days, there was no significant difference (p > 0.05) between growth rates of fish fed 7 different diets with various levels of Nutrafito. There were no mortalities during the experiment.;In the third trial, 20 tanks (140 L each) were stocked with 10 shrimp each. Tanks were divided into 5 treatments with 4 replicates each. There was significant difference (p 0.05) between growth rates of shrimp fed 5 different diets, with higher growth rate at higher levels of inclusion.;In the fourth trial, 15 tanks (140 L each) were stocked with 10 shrimp each. Tanks were divided into 5 treatments with 3 replicates each. There was significant difference between growth rates and feed conversion ration of shrimp fed 5 different diets. In addition, an analysis for digestive enzymes activity was done and no significant difference (p > 0.05) was found between treatments.