Diferentes intervalos de coleta na determinação da digestibilidade aparente da proteína e da energia de ingredientes comuns para o apaiari (Astronotus ocellatus).

This study evaluated the apparent protein and energy digestibility of common feed ingredients (soybean meal, fish meal, wheat meal and corn) by juvenile oscars using two different sampling intervals (30 min. and 12h). The 160 juvenile oscar fish tested (22.37 ± 3.06 g BW) were divided into four cylindrical plastic net cages, each one placed in a 1000 L feeding tank. The experiment was completely randomized in a 2 x 4 factorial design (2 feces collection intervals and 4 feed ingredients) with four replications. The statistical tests did not detect an interaction effect of sampling interval and type of ingredient on digestibility coefficients. Sampling interval did not affect protein and energy digestibility. The physical characteristics of juvenile oscar feces likely make them less susceptible to nutrient loss by leaching and can therefore be collected at longer intervals. Protein digestibility of the different ingredients was similar, showing that apparent digestibility of both animal and plant ingredients by juvenile oscars was efficient. Energy digestibility coefficients of fish meal and soybean meal were higher than those of wheat meal and corn. Carbohydrate-rich ingredients (wheat meal and corn) had the worst energy digestibility coefficients and are therefore not used efficiently by juvenile oscars

Morphometric Growth Characteristics and Body Composition of Fish and Amphibians

Describing animal growth through the nonlinear models allows a detailed evaluation of their behavior, besides revealing important information of the response to a particular treatment. In this chapter, the parameters of mathematical models (Gompertz, Von Bertalanffy, Logistic and Brody) for live weight, feed and protein intakes, total and standard lengths and nutrient deposition are described systematically and comprehensively. Also the relative growth and allometric coefficients of body components in relation to body weight of fish and amphibians are described, explaining better the use of the allometric equation and classifying the growth of the body components