Densidade de estocagem de Pangasius hypophthalmus (Sauvage, 1878) criado em sistema raceway

• Autor(a) principal: Rodrigues, Juliano Silva
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/10413
• topic: Estresse; Hemograma; Metabolismo de teleósteos; Perfil bioquímico sérico; Rendimentos corporais; Siluriformes; Carcass yields; Hemogram; Metabolism of teleost; Stress; Serum biochemical profile; Siluriformes; ZOOTECNIA::PRODUCAO ANIMAL

The adjustment of stocking density for fish with potential for fish farming, characterizes the beginning of technological package development activities, which can help in the creation of new species. The objective of this study was to evaluate the effect of stocking density on the productive and physiological parameters of the Pangasius hypophthalmus during the production period. 700 fish with initial weight of 527.91 ± 73, 40g were distributed in a completely randomized design, consisting of five treatments and four replications. The fish were housed in 20 polyethylene boxes with a volume of 500 liters of water, which corresponded to the five treatments of 30, 50, 70, 90 and 110 fish/m3 , representing 15, 25, 35, 45 and 55 fish per experimental unit. Feeding was performed twice a day, seven days a week, with commercial feed extruded to omnivorous, containing 32% of crude protein (CP) and granulometry of 4 to 6 mm. The experimental period lasted 90 days. The Growth performance was evaluated by the variables of body weight gain, feed intake, feed conversion ratio and survival rate. The temperature, dissolved oxygen, pH, nitrite, total and non-ionized ammonia were the limnological variables evaluated. As for carcass yields and biometric index, fillet yield, eviscerated fish yield, head proportion, hepatosomatic index and visceral fat index, weight of the block of viscera, relative weight of the intestine and relation body length/intestine length. Blood biochemistry was evaluated through the concentrations of glucose, chloride, lactate, total protein, total cholesterol, triglycerides, HDL, LDL and VLDL. Complete cell blood count was performed. The data were subjected to analysis of variance, test of comparison between means and application of regression models to the significance level of P< 0.05. Statistical analyses were performed using the computational program R. Feed conversion ratio and survival rate were not influenced by the rearing density. It was observed quadratic effect of stocking densitiy on fish final weight (FW) and linear effect on body weight gain (BWG), feed intake (FI), final biomass (FB) and biomass gain (BG). The limnological variables of temperature (T °C), hydrogenionic potential (pH) and dissolved oxygen (DO) were not affected by the stocking density, unlike nitrite (NO2-) levels, total ammonia (NH4+ + NH3 ) and non-ionized ammonia (NH3 ), which presented Increasing linear effect by influence of stocking density. The weight of the no edible compounds increased as the stocking density increased. The carcass yield, serum biochemical profile and hematology were not influenced by stocking density. It is concluded that for the cultivation of P. Hypophthalmus in intensive system and tropical climatic conditions, stocking densities above 87 fish/m3 , provides better fish development in the fating period of 90 days.