ABSTRACT This study aimed to evaluate the effect of different proportions of soybean and linseed oil to replace fish oil in diets for female lambari (Astyanax altiparanae). A completely randomized design with seven treatments and five replicates was used. The treatments consisted of a diet containing fish oil and six diets containing different proportions of soybean oil (S) and linseed oil (L), 10S/0L, 8S/2L, 6S/4L, 4S/6L, 2S/8L and 0S/10L. The fish that received the highest proportion of linseed oil (0S/10L) had the lowest crude lipid in their carcasses. The highest linolenic acid (18:3n3) concentrations were detected in the carcasses of fish fed diets with high proportions of linseed oil (4S/6L, 2S/8L, and 0S/10L). The highest n6/n3 ratios corresponded to the carcasses of fish fed diets containing the lowest proportions of linseed oil (10S/0L and 8S/2L). The highest levels of 20:5n3 (eicosapentaenoic acid [EPA]), 22:6n3 (docosahexaenoic acid [DHA]) and ZEPA+DHA occurred in fish fed diets containing fish oil. Among the fish that received diets with vegetable oils, the ZEPA+DHA was higher in the fish of the treatments 4S/6L, 2S/8L and 0S/10L. Diets supplemented with a 4S/6L proportion provide adequate deposition of the n3 fatty acids series in the lambari carcass.

RESUMO O objetivo deste estudo foi avaliar o uso de gelatina comercial em substituição total do coração bovino no condicionamento alimentar de pacamãLophiosilurus alexandri em diferentes salinidades da água. O experimento foi realizado em delineamento inteiramente casualizado, em esquema fatorial 2 × 3, usando dois tipos de ingredientes úmidos (coração bovino e gelatina) e três salinidades da água (0,0; 2,0 e 4,0 g de sal L-¹) com três repetições cada. Juvenis (2,39 ± 0,08 cm de comprimento padrão e 0,20 ± 0,03 g de peso) foram condicionados a aceitar dietas comerciais através da técnica da transição gradual de ingredientes. Após 36 dias de experimento não foram observadas diferenças significativas para o ganho de peso, ganho em comprimento e taxa de crescimento específico. A eficiência do condicionamento alimentar foi melhor (P <0,05) com o uso da gelatina (100%). Houve efeito negativo da salinidade da água na sobrevivência e eficiência do manejo na concentração de 4 g de sal L-¹, com valores de 58,6 ± 12,0% e 58,0 ± 12,0%, respectivamente. Juvenis de Lophiosilurus alexandri podem ser condicionados a aceitar dietas comerciais com o emprego da gelatina em substituição total do coração bovino, em água doce ou na salinidade de 2 g de sal L-¹.

ABSTRACT The aim of this study was to evaluate commercial gelatin in the total replacement of bovine heart in feed training of "pacamã" Lophiosilurus alexandri in different water salinities. A completely randomized experimental design, in a 2 × 3 factorial arrangement, was performed using two types of moist ingredients (bovine heart and gelatin) and three water salinities (0.0; 2.0 and 4.0 g of salt L-1) with three replications. Juveniles (2.39 ± 0.08 cm standard length and 0.20 ± 0.03 g of weight) were conditioned to accept commercial diets by the technique of the gradual transition of ingredients. At the end of 36 days no differences were observed to weight gain, length gain and specific growth rate. The feed training efficiency was better (P < 0.05) with the gelatin use, 100.0%. There was a negative effect of salinity on the survival rate and management efficiency in the concentration of 4 g of salt L-1, with values of 58.6 ± 12.0 % and 58.0 ± 12.0 %, respectively. Lophiosilurus alexandri juveniles could be feed-trained to accept commercial diets with gelatin in the total replacement of bovine heart in freshwater or salinity of 2 g of salt L-1.