Data/hora: 06/06/2024 07:50:45

Provedor de dados: 	Revista Brasileira de Zootecnia	
País: 	Brazil	
Título: 	Metabolic and histologic responses of pacu (Piaractus mesopotamicus) fed diets supplemented with increasing concentrations of ractopamine	
Autores: 	Drumond,Mariana Martins; Naves,Luciana de Paula; Ribeiro,Paula Adriane Perez; Oliveira,Marinez Moraes de; Okamura,Daniel; Resende,Anaise Emanuele; Cantarelli,Vinicius de Souza; Rosa,Priscila Vieira.	
Data: 	2018-01-01	
Ano: 	2018	
Palavras-chave: 	Beta-adrenergic agonist; Enzyme; Metabolism; Stress.	
Resumo: 	ABSTRACT An experiment was conducted during 60 days with forty pacu males fed diets supplemented with increasing concentrations of ractopamine (0.00, 11.25, 22.50, 33.75, and 45.00 mg kg−1). Eight fish were evaluated for each experimental diet. Performance and survival rate of the fish were measured. At the end of the experiment, blood was collected to determine the levels of cortisol, triacylglycerol, and protein. Moreover, the liver was collected to determine the activities of glucose-6-phosphate dehydrogenase and malic enzymes. The fillets were collected to determine chemical composition, and histologic cuts were analyzed to verify muscle growth and deposition of adipose tissue between muscle fibers. Increasing concentrations of dietary ractopamine did not change feed intake, fillet yield, fillet content of protein and ash, and frequency of relative distribution of muscle fibers. By increasing the dietary ractopamine concentration, the serum cortisol level was elevated. Ractopamine supplementation (45.00 mg kg−1) increased serum levels of triacylglycerol and protein and reduced the activity of hepatic lipogenic enzymes and the survival rate of the fish, probably in response to the high concentration of circulating cortisol. In addition, the higher level of ractopamine supplementation evaluated in this research impaired the weight gain and feed conversion. However, 11.25 mg kg−1 ractopamine reduced the ether extract level determined in the fillet and the fat deposition between muscle fibers, improving the nutritional quality of meat.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982018000100100	
Editor: 	Sociedade Brasileira de Zootecnia	
Relação: 	10.1590/rbz4720160234	
Formato: 	text/html	
Fonte: 	Revista Brasileira de Zootecnia  v.47 2018	
Fonte: 	info:eu-repo/semantics/openAccess