Sorgo sem tanino em dietas de juvenis de tambaqui

Abstract

With the increase in the consumption of fish by the population and as the fishing reached its maximum limit, the most viable way to reach the growing demand is through fish farming. However, research must be carried out with a view to improving animal performance and reducing feed costs. The substitution of conventional ingredients denotes a viable option to reduce feed costs. Sorghum without tannin is an energetic ingredient that has nutritional similarity to corn. The present study aimed to evaluate the replacement of corn by different levels of sorghum without tannin in the diet of tambaqui juveniles (Colossoma macropomum) in zootechnical performance and in the cost of formulating the feed. The experiment was conducted in the Fish Farming Sector of Embrapa Amazônia Occidental, Manaus, and Amazonas, Brazil. The experiment was conducted in a completely randomized design (DIC) in 6 treatments (replacement of corn in 0, 20, 40, 60, 80 and 100% by sorghum) x 4 replicates. The experimental units consisted of lots of juvenile tambaqui with 7 fish per 70 L cage with an initial average weight of 30 g and an initial average length of 10 cm, housed in 1,000 L water tanks. Ingredients corn, soybean meal, sorghum without tannin (cultivar BRS 330), common salt, soybean oil, dicalcium phosphate, mineral and vitamin premix. Formulated in the Super Crac version 5.7 program, meeting the requirements of the animals and according to the replacement levels. The fish were fed for 60 days. The zootechnical performance indexes (weight gain (GP), apparent feed conversion (CAA), specific growth rate (TCS) and somatic relationships), measurement of circulating glucose and an exploration of the cost benefit of the formulated feed were evaluated. The results showed that for weight gain, the substitution of 0 to 100% did not present statistical difference. In the liposomal relation parameter, 100% replacement showed less deposition of peritoneal fat. The replacement of 80% of corn by sorghum resulted in a lower production cost, being 27.4% lower compared to the control. The other parameters evaluated showed no statistical difference. It was concluded that sorghum can replace corn in diets for tambaqui juveniles without any negative changes in zootechnical performance, however, the most recommended substitution corresponds to 85%, as it presented better performance, lower production cost and better carcass quality of the fish produced.