CORPORAL COMPOSITION OF SWINE FEED FROM 10 TO 20 KG WITH DIETS CONTAINING DIFFERENT LEVELS OF LYSINE AND CRUDE PROTEIN Composição corporal de suínos alimentados dos 10 aos 20 kg com rações contendo diferentes níveis de lisina e proteína bruta

ABSTRACT The aim of this work was to verify the effect of different levels of true digestible lysine (TDL) and crude protein (CP) ondiets on the carcass composition of the swine in the nursery phase. Eighty piglets Landrace x Large White, barrows and females, withinitial weight of 9.1±1.2 kg and final weight of 21.5±4.8 kg, weaned at the 28 days, allotted in groups of two during 35 days in thenursery. A randomized block design in factorial 2x4 (two levels of CP - 16 and 18% - and four of TDL - 0.7; 0.9; 1.1 and 1.3%) withfive repetitions was used. After weighing, one animal of each stall was sacrificed and the carcass utilized for determination of water(CWP), protein (CPP) and lipid (CLP) percentage and deposition tax of the protein (DTP) and lipid (DTL). There were nodifferences for CWP, but there was had quadratic effect of the lysine levels on the CPP and DTP in the carcasses only in 18% CPdiets, being 1.02% of TDL that propitiated the best result for DTP. There was no difference in 16% CP diets. For the CLP, there wereno differences when 18% CP diets were utilized, however there was had quadratic effect with 16% CP diets, being 0.99% the levelof TDL that provided the higher deposition. For the DTL, the 1.08 and 1.00% of TDL resulting in higher values in 18 and 16% CPdiets, respectively. One concluded that 18% CP diets is the ideal and the 1.02% of TDL must be kept for the best carcass compositionof swine in the initial phase.Index terms: Synthetic amino acids, carcass composition, nutrition, piglets.RESUMOObjetivou-se verificar o efeito dos niveis de lisina digestivel verdadeira (LDV) e proteina bruta (PB) nas racoes sobre acomposicao de carcaca de suinos na fase inicial. Foram utilizados 80 suinos Landrace x Large White, machos castrados e femeas, compeso inicial de 9,1±1,2 kg e final de 21,5±4,8 kg, desmamados aos 28 dias, alojados em grupos de dois, durante 35 dias na creche. Foiutilizado um delineamento em blocos casualizados em esquema fatorial 2x4 (dois niveis de PB – 16 e 18% e quatro de LDV – 0,7; 0,9;1,1 e 1,3%) com cinco repeticoes. Apos a pesagem, um animal de cada baia foi abatido e as carcacas utilizadas para determinacao daporcentagem de agua (%A), proteina (%P) e lipidios (%L) e taxa de deposicao de proteina (TDP) e lipidios (TDL). Nao houvediferencas para %A na carcaca. Houve efeito quadratico dos niveis de lisina na %P e TDP na carcaca apenas em racoes com 18% PB,sendo 1,02% de LDV o nivel que proporcionou melhor resultado. Nao houve diferenca em racoes com 16% PB. Para %L, nao houvediferenca quando 18% PB foi utilizado, porem houve efeito quadratico com 16% PB, sendo 0,99% o nivel de LDV que proporcionoua maior deposicao. Para TDL, os niveis de 1,08 e 1,00% de LDV resultaram em maiores valores em racoes com 18 e 16% PB,respectivamente. Conclui-se que 18% PB na racao e o ideal e que 1,02% de LDV deve ser mantido para uma melhor composicao decarcaca de suinos na fase inicial.Termos para indexacao: Aminoacido sintetico, composicao da carcaca, nutricao, leitoes.