Effects of partial replacement of fishmeal with isolated soy protein on digestibility and growth performance in sterlet (Acipenser ruthenus)

Fishmeal was partially replaced by isolated soy protein in diets for sterlet (Acipenser ruthenus) juveniles at an amount at which one-half or one-third of the protein was supplied by soy. Nutrient digestibility, growth, and whole body composition were determined after 79 days. Protein digestibility was significantly higher in the diet in which half the protein derived from isolated soy protein (84.9%) than in the diet in which one-third of the protein derived from soy (82.6%). Otherwise, digestibility, growth, feed efficiency, and whole body composition did not differ between the two diets.