Performance and carcass characteristics of swine at 50 kg fed diets with different energy levels and reduced levels of crude protein

• Autor(a) principal: Zangeronimo, Márcio Gilberto
• Data de Publicação: 2009
• Outros Autores: Cantarelli, Vinícius de Souza, Fialho, Elias Tadeu, Amaral, Nikolas de Oliveira, Silveira, Hebert, Lima, José Augusto de Freitas
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFLA
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542009000300034; http://repositorio.ufla.br/jspui/handle/1/6981
• topic: Digestible amino acid; Synthetic lysine; Swine production; Ideal protein; Aminoácido digestível; Lisina sintética; Suinocultura; Proteína ideal

The aim of this work was to evaluate the effects of different levels of metabolic energy (ME) in diets with a reduced level of crude protein (CP) on the performance and carcass characteristics of growing swine. Thirty-two high-performance barrows (initial weight of 22.5 ± 1.43 kg and final weight of 50.81 ± 2.54 kg) were distributed in a randomized block design with four treatments (three levels of ME - 3,060, 3,230 and 3,400 kcal/kg - in diets with 14% CP, and one control treatment with 3,230 kcal ME/kg and 18% CP) and four replicates. The diets were formulated with a true digestible basis of amino acids present in the feed, with methionine and threonine concentrations corrected as a function of lysine levels. The animals were slaughtered and their carcasses were studied. The ME levels did not affect the average weight gain, the feed:gain ratio, the backfat thickness or the loin eye area. A higher carcass yield and a higher carcass meat:fat ratio were observed in the animals that received the 3,230 and 3,060 kcal/kg ME levels. Compared to the control treatment, only the 3,400 kcal/kg ME level had a lower average daily feed intake. It is concluded that the CP level in diet should be reduced from 18% to 14% and the metabolizable energy level should be increased, thus reducing the feed intake and increasing the carcass meat:fat ratio without affecting the animal weight gain.