Studies on the nutrition of Siberian sturgeon, Acipenser baeri: I. Utilization of digestible carbohydrates by sturgeon

Abstract

A growth trial was conducted to study the effects of incorporation of four different carbohydrate sources (crude, gelatinized or extruded starch, extruded whole corn) in practical diets (crude protein level: 36%) for Siberian sturgeon, Acipenser baeri. Another diet incorporating gelatinized starch was formulated at a higher protein level of 42%. Based on growth performance, body composition and nutrient retention efficiencies, it was found that growing juvenile Siberian sturgeon do not utilize well complex carbohydrates like crude starch. Extruded or pregelatinized starches or extruded corn can be used as an energy-yielding ingredient in sturgeon grower diets. The level of feeding has a great impact on feed efficiency, the optimal level being 1.45% of body weight per day for sturgeon weighing between 90 and 400 g. The results indicate that the protein requirement for optimal growth of Siberian sturgeon would be around 36%, but below 42%. In absolute terms, the daily protein requirement for optimum growth would amount to 3.7 g digestible protein/kg BW per day with a protein:energy ratio of 18 mg digestible protein/kJ DE. Histological studies revealed that high levels of digestible carbohydrates adversely affect liver size, morphology and function.