|KOBAYASHI, Y - Fort Hays State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/25/2016
Publication Date: 6/12/2016
Citation: Peterson, B.C., Kobayashi, Y. 2016. Use of ß-adrenergic agonists in hybrid catfish. 12th International Congress on Biology of Fish, San Marcos, TX. p. 23.
Technical Abstract: Ractopamine hydrochloride (RH) is a potent ß-adrenergic agonist that has been used in some species of fish to improve growth performance and dress out characteristics. While this metabolic modifier has been shown to have positive effects on growth of fish, little research has focused on the mechanism(s) of action through which RH improves growth. Hybrid catfish (251.5 g/fish) were fed RH at 20 ppm or a control diet for 4 weeks. Weight gain and food conversion ratio were improved in fish fed RH compared to control fed fish (P < 0.05). Carcass, fillet, and nugget yield were similar between treatments. Visceral fat percent and fillet proximate composition were not significantly affected by RH treatment. Similarly, there were no significant differences in levels of ß-2 and -3 adrenergic receptor mRNA between the two groups of fish. Dose of RH, number of days on feed, and age of fish may play importance roles in how fish respond to these metabolic modifiers.