Deposição de nutrientes na carcaça de girinos de rã-touro

Abstract

Resumo -O objetivo deste trabalho foi determinar a deposição de nutrientes na carcaça de girinos de rã-touro (Lithobates catesbeianus) por meio de modelo não linear. Foram utilizados 2.700 girinos com peso médio inicial de 0,039 g. Ração comercial farelada com 55% de proteína bruta foi fornecida ad libitum. Os animais foram pesados e avaliados a cada dez dias para análise dos conteúdos de proteína bruta, extrato etéreo, água e sais minerais. Os parâmetros do modelo Gompertz foram estimados pelo método de Gauss-Newton modificado, e as taxas de deposição (g por dia) em função do tempo foram calculadas por meio da derivada da equação. Os valores encontrados para os parâmetros da equação de Gompertz, para descrever a deposição dos nutrientes na carcaça de girinos, apresentaram interpretação biológica. A taxa máxima (t*) de deposição foi observada aos 36,2331 dias para proteína, aos 37,1420 dias para água, aos 35,2971 dias para sais minerais, e aos 41,3547 dias para gordura. O consumo de nutrientes da dieta é maior do que a taxa de deposição na carcaça dos girinos.Termos para indexação: Lithobates catesbeianus, composição corporal, modelo de Gompertz, nutrição. Nutrient deposition in bullfrog tadpole carcassAbstract -The objective of this work was to determine nutrient deposition on the carcass of bullfrog (Lithobates catesbeianus) tadpoles using a nonlinear model. A total of 2,700 tadpoles with an average weight of 0.039 g were used. Commercial ground feed containing 55% crude protein was offered ad libitum. The animals were weighed and evaluated every ten days for analysis of crude protein, ether extract, water, and mineral salt contents. The parameters of the Gompertz model were estimated by the modified Gauss-Newton method, and the deposition rates (g per day) over time were calculated by the resulting equation. The values found for the parameters of the Gompertz equation, used to describe nutrient deposition on tadpole carcass, showed biological interpretation. Maximum deposition rate (t*) was observed on the 36.2331 th day for protein, on the 37.1420 th day for water, on the 35.2971 th day for mineral salt, and on the 41.3547 th day for fat. Nutrient intake from the diet is higher than the deposition rate on the tadpole carcass.

<b>Comparing non-linear mathematical models to describe growth of different animals

“…Usually, these models consist of nonlinear functions and several studies including different mathematical models can be found in the literature. These models are usually applied for the evaluation of the growth kinetics of a wide range of animals, including birds (Aggrey, 2002;Sezer & Tarhan, 2005;Nahashon, Aggrey, Adefope, Amenyenu, & Wright, 2006), mammals (Curi, Nunes, & Curi, 1985;Silva, Alencar, Freitas, Packer, & Mourão, 2011;Franco et al, 2011), fishes (Hernandez-Llamas & Ratkowsky, 2004;Santos, Mareco, & Silva, 2013), reptiles (Bardsley, Ackerman, Bukhari, Deeming, & Ferguson, 1995) and amphibians (Rodrigues et al, 2007;Mansano, Stéfani, Pereira, & Macente, 2013). Some mathematical functions commonly used in these studies include the Gompertz, Logistic, Brody, von Bertalanffy and Richards growth models (France et al, 1996).…”

Performance of bullfrog tadpoles (Lithobates catesbeianus) fed balanced diets using alternative energy ingredients containing vegetable mesocarp

“…The water (87.29% to 88.83%), protein (6.14% to 7.35%), fat (2.69% to 3.37%), and ash (1.36% to 1.42%) content of tadpoles fed corn and peeled banana, avocado, and pumpkin meal correspond to studies that determined the protein requirement for bullfrog tadpoles (Pinto et al, 2015). Additionally, they correspond to studies that compared the nutrient content between a commercial and an experimental diet for bullfrog tadpoles (Mansano et al, 2014), and research evaluating the nutrient deposition using a commercial fish diet containing 40% crude protein (Mansano et al, 2013). Histological studies of the organs of bullfrog tadpoles have shown that diets formulated for fish can cause organ damage in the tadpoles, even those containing low protein (Seixas Filho et al, 2008a).…”

Polyculture of bullfrog tadpoles and Nile tilapia fry

“…Similar results have been described for bullfrog tadpoles fed a diet with 270 g/kg digestible protein, which showed a centesimal composition of 851.5 g/kg moisture, 87.9 g/kg protein, 44.3 g/kg fat, and 15.7 g/kg ash (Pinto et al, 2015). In another study, the same species receiving commercial feed with 550 g/ kg CP showed a centesimal composition of 881.5 g/kg moisture, 70.0 g/kg protein, 36.0 g/kg fat, and 12.4 g/kg ash (Mansano et al 2013). In an experiment using a commercial feed containing 360.00 g/kg CP, bullfrog tadpoles had a body composition consisting of 863.8 g/kg moisture,…”