Effect of Feeding Frequency and Restriction on the Growth Performance, Physiology, and Intestinal Histomorphometry of Colossoma macropomum in a Recirculating Aquaculture System

This study investigated the growth performance and physiological and intestinal histomorphometry of juvenile tambaqui Colossoma macropomum (51.68 ± 3.87 g), fed continuously or subjected to weekly cycles of feed restriction (one day of no feeding followed by six days of feeding) associated with feeding frequencies of two or three times a day, for 84 days, in a recirculating aquaculture system (RAS). Growth performance and blood parameters were determined after 42 and 84 days. Liver, adipose tissue and intestine were collected after 84 days to determine the somatic indices, liver lipid levels and intestinal histomorphometry. Restricted fish had greater feed intake compared to continuously fed after 42 days, as well as greater specific growth rate (SGR) and better feed conversion between 43 and 84 days. No significant differences were observed for restriction, feeding frequency or the interaction for blood parameters after 42 and 84 days, somatic indices and liver lipid levels after 84 days, with the exception of plasma glucose, which was higher for restricted fish after 84 days. The feed restriction promoted a greater intestinal villi perimeter and height compared to continuously fed fish, as did fish fed twice a day compared to those fed three times a day, with an interaction between factors. We concluded that six days of feeding per week and twice-daily feeding frequency can be used as a feeding protocol for tambaqui juveniles over an 84-day period in RAS and this management protocol can also help reduce feed and labor costs in the production of this species.