Evaluation of in vitro and in vivo digestibility of potential feed ingredients for juvenile Yellowtail Snapper

Abstract

Objective: The carnivorous Yellowtail Snapper Ocyurus chrysurus has the potential for production in aquaculture. However, there is a lack of studies investigating the digestibility of ingredients needed to formulate balanced diets for this species. Methods: The in vitro protein digestibility of fish meal (FM), poultry by-product meal (PBM), poultry meal (PM), protiblend, canola meal (CM), soybean meal, and wheat gluten was evaluated using the pH-stat technique. The in vivo digestibility was determined by formulating test diets with a 70:30 ratio of the reference diet and the test ingredients. Result: In terms of in vitro digestibility, FM, PBM, and PM exhibited the highest degree of hydrolysis (DH). Conversely, PBM displayed the lowest apparent digestibility coefficient of protein (ADCprotein) in the in vivo digestibility test. Meanwhile, FM, PM, and CM demonstrated higher values of protein digestibility. Beta regression between ADCprotein and the DH and ash content of the ingredients resulted in a high correlation (R2 = 0.94). Conclusion: The results of the present study indicate that Yellowtail Snapper efficiently digested and absorbed FM, PM, and CM ingredients, which contain a lower content of ash.