Carbohydrates use as protein-sparing effect for surubins (Pseudoplatystoma corruscans)

• Grant number: 12/13526-8
• Support type: Scholarships in Brazil - Master
• Effective date (Start): March 01, 2013
• Effective date (End): February 28, 2014
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal researcher: Leonardo Susumu Takahashi
• Grantee: André Fernando Nascimento Gonçalves
• Home Institution: Universidade Estadual Paulista (UNESP). Campus Experimental de Dracena. Dracena , SP, Brazil

Abstract

The carbohydrates accurate use in the diets of carnivorous fish has reduced the dietary protein fraction for energy purposes and has improved its use for growth, in a process known as protein-sparing effect. The surubim is a carnivorous catfish, with potential for aquaculture, besides the use for sport fishing. Anatomy and histology of digestive system of surubins demonstrate that they have particularities similar to omnivorous which could promote better carbohydrates utilization in the diet. Due to the lack of studies in native species in general, the present study will evaluate the protein-sparing effect, through diets with decreasing protein levels and increasing carbohydrate levels, evaluating the growth performance, the efficiency in nutrients retention, the dynamics of tissue energy reserves, the metabolites profile in the blood and the activities of the amylase enzymes. In order to assess the hepatic metabolic pathways, the activity of glucokinase (GK)/hexokinase (HK), and pyruvate kinase (PK); 1.6-fructose-bisphosphatase (gluconeogenesis pathway) and glucose-6-phosphate dehydrogenase (lipogenesis pathway) will be determined. (AU)