Composição corporal de tambatingas juvenis (♀ Colossoma macropomum × ♂ Piaractus brachypomus ) alimentados com dietas com diferentes níveis de energia digestível

Meeting dietary energy requirements is crucial for nutrient utilization efficiency, growth, and body composition in fish. Tambatinga (Colossoma macropomum × Piaractus brachypomus) is one of the main hybrids in Brazilian fish farming; however, few studies have evaluated the effect of dietary energy levels on its body composition. This study aimed to evaluate the effect of different digestible energy (DE) levels on the body composition of juvenile tambatinga. To this end, 200 juveniles (29.74 ± 0.20 g) were distributed in a completely randomized design and fed for 50 days with five isoproteic diets (31% crude protein) containing 2,900, 3,000, 3,100, 3,200, and 3,300 kcal DE kg⁻¹. To avoid confounding results due to potential variations in intake, the diets were provided in equal amounts across all treatments and adjusted every five days. Data on body moisture, protein, fat, and ash were subjected to analysis of variance and regression analysis at a 5% probability level. Increasing DE levels from 2,900 to 3,300 kcal kg⁻¹ resulted in a linear increase (P < 0.05) in digestible energy intake. However, no effect (P > 0.05) was observed on body protein content. Conversely, increasing dietary DE levels led to a quadratic reduction (P < 0.05) in ash content, with an estimated optimal level of 3,134 kcal kg⁻¹. A linear reduction (P < 0.05) in moisture content and a linear increase (P < 0.05) in fat content were also observed. The increase in fat content indicates that the excess energy from the feed was stored as lipids. Thus, diets containing 2,900 kcal of DE kg⁻¹ do not influence the body composition of juvenile tambatinga.