Effect of ractopamine on Nile tilapia in the end of grow-out period

Abstract

-This experiment was conducted in outdoor tanks to evaluate the effect of inclusion of ractopamine at increasing levels (0, 4, 8, 12, and 16 mg kg −1 ) as additive in Nile tilapia (Oreochromis niloticus) diet in the final grow-out period (750-920 g) during 31 days. Therefore, 400 fish were housed into 20 experimental tanks, in a completely randomized design with five treatments and four replications. Growth performance, body yield, and chemical composition of fish muscle and organs were evaluated. Fish fed diets containing up to 16 mg kg −1 of ractopamine for 31 days did not improve growth or performance parameters. However, lipid percentage of abdominal muscle was different in fish fed ractopamine, reaching the lowest level of 199.3 g kg −1 of ether extract at 8 mg kg −1 treatment. Other body chemical composition parameters did not differ between animals treated or not treated. Feeding ractopamine up to 31 days has limited effect on body composition in Nile tilapia (~900 g), without any changes in growth parameters. This is a lower metabolic response in this species when compared with mammals and other terrestrial animals.

Ractopamine supplementation in diets for Nile tilapia (Oreochromis niloticus) at grow-out phase: effect on body composition and fatty acid profile

“…They promote an increase in muscle protein deposition and a decrease in fat accumulation in some fish species such as Ictalurus punctatus (Rafinesque) (Mustin & Lovell 1993, 1995, Oncorhynchus mykiss (Walbaum) (Moccia et al 1998, Jalali et al 2010. Few reports are available using Nile tilapia (Oreochromis niloticus) (Mundim et al 2016, Tovo-Neto et al 2017).…”

Ractopamine supplementation in diets for Nile tilapia at grow-out phase: effect on body composition and fatty acid profile

“…Despite the regularization of the use of RAC as an additive in swine feed in more than 20 countries, especially the United States and Brazil, for aquatic organisms there is still no regulation of the use of RAC as a food additive. However, some studies have shown that the use of RAC in food improves productive performance and body composition, promoting an increase in muscle protein deposition and a decrease in fat accumulation in some sh species such as Ictalurus punctatus (Ra nesque) (Mustin and Lovell 1993;Mustin and Lovell 1995), Oncorhynchus mykiss (Walbaum) (Haji-abadi et al 2010;Moccia et al 1998), and also few reports are available using Nile tilapia (Mundim et al 2016;Tovo-Neto et al 2017).…”