Desempenho zootécnico e metabólico de girinos de rã-touro (Lithobates catesbeianus Shaw, 1802) submetidos a diferentes dietas

Abstract

The development of raniculture in Brazil and in the world is dependent on scientific knowledge and training of skilled labor, since there is a great lack of this area, to act in assisting producers. The meat of the frog stands out from the others for its high nutritional value, its high digestion capacity and is indicated for medical treatments. The Bull Frog Lithobates catesbeianus is one of the main species cultivated worldwide, being a critical point in the production the absence of specific rations for the different phases of development of the crop. The objective of this work was to evaluate the zootechnical performance and metabolic and enzymatic profile of tadpoles submitted to different feeding sources, consisting of four treatment groups; 1) rabbit ration, 2) fish ration, 3) rabbit ration with 50% spinach external supplementation, 4) fish ration with 50% external spinach supplementation. First 60 animals were weighed allocated in 60 individual 01 liter aquarium, distributed randomly in the 4 groups of treatments. In the second, 16 animals were weighed and distributed in 4 aquariums of 4 liters in density of 1 animal / liter corresponding to the four treatment groups. After 40 days of experiment, the animals were weighed to verify the rate of weight gain, subsequently anesthetized and sacrificed for the collection of muscle, liver and intestinal tissue to perform biochemical tests for important metabolic pathways. In order to identify alterations in amino acid metabolism, transaminase activity analyzes (TGO and TGP) of muscle and liver were performed. To identify possible interferences in the antioxidant defense system, analyzes of lipid peroxidation (LPO) and activity of the catalase enzyme, both in liver and muscle, were performed. For the identification of possible influences on carbohydrate metabolism, the activity of the digestive enzymes amylase, sucrase, maltase and lactase in intestine and glycogen concentration in liver and muscle were performed. The diets given to the animals did not interfere in the development and, in the weight gain rates, either in the individual culture assay or in pooled assay. However, in the treatment with fish feed, with and without spinach, the largest weights were observed and mortality of tadpoles was observed. No differences were observed between treatments in relation to the activity of TGO, TGP, catalase, LPO levels, glycogen concentration and in the digestive enzymes disaccharidases, maltase, lactase and sucrase, but less activity of the amylase enzyme was observed in animals treated with ration Rabbits in relation to fish meal and rations supplemented with spinach. It is concluded that the diet can be used to feed tadpoles without altering the metabolism or growth of the animals. Considering that rabbit ration presents lower cost and that spinach can be grown on the property, the study demonstrates that more economical cultivation alternatives can be selected, contributing to the economic development of raniculture. To prove this alternative, studies must be carried out on a commercial scale.