Intestine histology, nutrient digestibility and body composition of Nile tilapia (Oreochromis niloticus) fed on diets with both cotton and sunflower seed cakes

Physiological response of Nile tilapia to diets with both sunflower (SFSC) and cotton seed cakes (CSC) at increasing proportions (10%CSC25%SFSC; 15%CSC20%SFSC; 20%CSC15%SFSC; 25%CSC10%SFSC and a control that was a commercial tilapia diet) was investigated in two trials using diets containing 25% crude protein. Trial 1 run for 120 days in 15 happas of 1 m super(3) stocked with 35 fish of 5.72 g. Each treatment had three replicates. Fish were fed 4% of their body weight per day. The number and length of intestinal folds was investigated. Trial 2 was run for 60 days in 24 tanks with 60 L of water and 30 fish of 3 g. Each treatment had six replicates fed to apparent satiation. Nutrient digestibility and body composition were determined. The test diets did not negatively affect the number and length of intestinal folds as they were similar to the control. The diets with 10%CSC25%SFSC and 20%CSC15%SFSC had the most efficiently digested protein, and highest protein deposition implying that the dietary protein was effectively used. The formulations with 10%CSC25%SFSC and 20%CSC15%SFSC could be used for making Nile tilapia diets.