Digestible lysine for growing gilts/Lisina digestivel para leitoas em fase de crescimento

• Published in: Ciência rural Vol. 43; no. 5; p. 871
• Main Authors: Rocha, Gabriel Cipriano, Donzele, Juarez Lopes, Donzele, Rita Flavia Miranda de Oliveira, da Silva, Francisco Carlos de Oliveira, Kiefer, Charles, Alebrante, Leandro, Paulino, Pedro Veiga Rodrigues, Serao, Nicola Vergara Lopes
• Format: Journal Article
• Language: Spanish
• Published: Universidade Federal de Santa Maria 01-05-2013
• Subjects: Analysis; Lysine; Nutritional requirements
• ISSN: 0103-8478

Eighty gilts (24.2 [+ or -] 1.52kg) with high genetic potential for lean gain were used in a randomized complete block design to evaluate five digestible lysine levels (9, 10, 11, 12 and 13g [kg.sup.-1]) during the growing phase (63 to 103 days of age). Gilts were housed in pair and fed their respective diets ad libitum. At the begging and the ending of the experimental period, gilts were weighed and scanned by ultrasound to measure loin area, as well as fat depth. The digestible lysine levels linearly increase (P<0.05) average daily gain and loin area of gilts in growing phase. However, there was no difference for average daily gain at levels above 12g [kg.sup.-1] while the "Linear Response Plateau " model was that better fitted to the loin area data that stabilized in a plateau starting from the level of 12.5g [kg.sup.-1]. The feed:gain ratio was improved (P<0.01) quadratically until the estimated level of 11.9g [kg.sup.-1] of digestible lysine. There was no effects (P>0.05) of the treatments on the fat depth and feed intake. The digestible lysine levels of 12 and 12.5g [kg.sup.-1], corresponding to the intake of 23.6 e 24.6g dia', provide the best results of performance and loin area of growing gilts (63 to 103 days old). Key words: carcass, performance, nutritional requirements, swine. Oitenta leitoas (24,2 [+ or -] l,52kg) com alto potencial genetico para deposicao de carne na carcaca foram distribuidas em experimento de blocos ao acaso para avaliar cinco niveis de lisina digestivel (Ld) (9, 10, 11, 12 e 13g [kg.sup.-1]) durante a fase de crescimento (63 a 103 dias de idade). Os animais foram alojados em pares e alimentados a vontade. No inicio e ao final do periodo experimental, as leitoas foram pesadas e submetidas a analise de ultrassom para avaliacao da area de olho de lombo (AOL) e espessura de toucinho (ET). Os niveis de Ld proporcionaram aumento linear (P<0,05) do ganho de peso diario (GPD) e, apesar dessa variacao, nao houve aumento no valor absoluto do GPD a partir do nivel de 12g [kg.sup.-1] de Ld. A conversao alimentar (CA) reduziu (P<0,01) de forma quadratica ate o nivel estimado de 11,9g [kg.sup.-1] de Ld. A AOL das leitoas aumentou (P<0,05) de forma linear. No entanto, o modelo "Linear Response Plateau " foi o que melhor se ajustou aos dados, estimando em 12,5g [kg.sup.-1] o nivel a partir do qual ocorreu plato. Nao foi verificada influencia (P>0,05) dos niveis de Ld sobre o consumo de racao diario (CRD) e ET. Os niveis de 12,0 e 12,5g [kg.sup.-1] de Ld na dieta, correspondentes, respectivamente, ao consumo de lisina digestivel diario (CLdD), de 23,6 e 24,6g, proporcionam os melhores resultados de desempenho e area de olho de lombo de leitoas em fase de crescimento (63 aos 103 dias de idade). Palavras-chave: carcaca, exigencia nutricional, desempenho, suinos.