Planos de nutrição baseados em níveis de lisina para suínos de dois genótipos abatidos aos 80 e 100 kg de peso vivo

Abstract

One performance and one metabolism assay were conducted in the swine sector of the Universidade Federa l de Lavras (UFLA), from October 21st, 1996 to January27th,1997,in order to evaluate the influence of the different levels of lyine in three feeding nutrition programs on the performance of swine of two different genotypes in the growing (30-55kg), finishing I (55-80kg) and finishing II (80-100kg) phases. A total of 84 barrows (being 12 metabolism assay and 72 performance assay) from two different genotypes (42 genotype I and 42 genotype II) were utilized. In the breeding composition of genotype I, the Landrace, Large White, Duroc, Belgian Landrace and Hampshire strains and for genotype II, Large White, Yorkshire and Pietrain strains in different percentages.The feeding programs used during all the production cicle were: Program A-0.90, 0.90 and 0.90% of lysine; Program B: 0.95, 0.95 and 0.85 of lysine; Program C:1.15, 1.05 and 0.95% of lysine for the growing, finishing I and finishing II phases, respectively. In the metabolism assay in growing and finishing phases the higher lysine level and Genotype II shown bether (P<0,01) Nitrogen Retention (NR) and Energy Balance(EB). In the performance assay the lysine level (feeding programs) had no influence (P>0,01) on the performance results on the diferents experimental phases (growing, finishing I and finishing II) as well as over all experimental period. Therefore the daily lysine intake (DLI) was influenced by growing and finishing phases as well as over all experimental period studied. The muscle growth rate (MGR) and musclein feeding convertion (MFC) was not affected (P>0,05) by lysine levels (feeding programs) tested. The pigs from genotype II shown better performance, MGR and DLI than those from genotype I, for growing, finishing I and finishing II phases and similar (P>0,05) feed Conversion and MFC. Considering that feeding programs (lysine levels) had no influence on pig performance on different phases, we should conclude that the minimum requirements for lysine should be 0.90% Lys and 3400 Kcal DE/Kg in the ration, that correspond to lysine intake of 21.90; 26.92 and 27.69 g/pig/day for growing, finishing I and finishing II phases respectively. The pigs also shoul be slaughtered at 80Kg,for attainment bether of lean meat performance. Also we conclude that the swine from genotype II shown bether performance than those from genotype I.