Nutritional requirements of digestible threonine for growing meat-type quails

• Autor(a) principal: Ton,Ana Paula Silva
• Data de Publicação: 2013
• Outros Autores: Furlan,Antonio Claudio, Martins,Elias Nunes, Batista,Eliany, Pasquetti,Tiago Junior, Scherer,Carina, Iwahashi,Alexandre Shigueki, Quadros,Thays Cristina Oliveira de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Zootecnia (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982013000700007
• topic: carcass composition; performance; synthetic amino acids

The objective of this study was to estimate the nutrient requirements of digestible threonine for meat-type quails (Coturnix coturnix sp) in the growth phase. A total of 1350 not sexed meat-type quails were distributed in a completely randomized design with six threonine levels (10.80, 11.50, 12.20, 12.90, 13.60 and 14.30 g/kg as fed), five replications and 45 quails per experimental unit, from 1 to 14 days of age. The threonine levels in the diet had a quadratic effect on body weight, feed intake and weight gain. Estimates for highest body weight (79.41 g), feed intake (128.96 g/bird) and weight gain (70.73 g) were observed with diets containing 12.60 g/kg of digestible threonine. According to the LRP model, the threonine intake was estimated at 13.40 g/kg of digestible threonine. Protein deposition rate and energy retained in the carcass showed quadratic effect, with estimated digestible threonine levels of 11.80 and 12.00 g/kg in the diet for maximum protein deposition rate (2.00 g/bird) and retained energy in the carcass (15.88 kcal/g), respectively. There was a linear effect on feed cost per kg of live weight gain as threonine levels were increased. Nutritional requirement of digestible threonine for meat-type quails for maximum growth is 12.60 g/kg, corresponding to a digestible threonine:digestible lysine ratio of 67.02.