Dietary lysine requirement for 7-16 kg pigs fed wheat-corn-soybean meal-based diets.

Abstract

Two experiments were conducted to determine the lysine requirement of weaned pigs [Duroc9(York-shire9Landrace)] with an average initial BW of 7 kg and fed wheat–corn–soybean meal-based diets. The exper-iments were conducted for 21 days during which piglets had free access to diets and water. Average daily gain(ADG), average daily feed intake (ADFI) and gain to feed ratio (G:F) were determined on day 7, 14 and 21. Bloodsamples were collected on day 0 and 14 to determine plasma urea nitrogen (PUN) concentration. In experiment1, 96 weaned pigs were housed four per pen and allocated to four dietary treatments with six replicates per treat-ment. The diets contained 0.99%, 1.23%, 1.51% and 1.81% standardized ileal digestible (SID) lysine, respec-tively, corrected analysed values. The rest of the AA were provided to meet the ideal AA ratio for proteinaccretion. Increasing dietary lysine content linearly increased (p<0.05) ADG and G:F. In experiment 2, 90 pig-lets were housed three per pen and allocated to five dietary treatments with six replicates per treatment. The fivediets contained 1.03%, 1.25%, 1.31%, 1.36% and 1.51% SID lysine, respectively, corrected analysed values.Increasing dietary lysine content linearly increased (p<0.05) G:F, linearly decreased (p<0.05) day-14 PUN andquadratically (p<0.05) increased ADG and ADFI. The ADG data from experiment 2 were subjected to linearand quadratic broken-lines regression analyses, and the SID lysine requirement was determined to be 1.29% and1.34% respectively. On average, optimal dietary SID lysine content for optimal growth of 7–16 kg weaned pigletsfed wheat–corn–SBM-based diets was estimated to be 1.32%; at this level, the ADG and ADFI were 444 and560 g, respectively, thus representing an SID lysine requirement, expressed on daily intake basis as, 7.4 g/day or16.76 mg/g gain.