Evaluation of the standardized ileal digestible lysine requirement of nursery pigs from 28 to 63 d of age in a three-phase feeding program

Abstract

The objective of this study was to determine the standardized ileal digestible lysine (SID Lys) requirement of nursery pigs from 28 to 63 d of age fed a multi-phase feeding (PF) program and its possible adaptation to SID Lys-deficient diets. Ninety-six commercial hybrid piglets (Topigs Norsvin, 46 castrated males and 50 females) that had been weaned at 28 d of age with an initial body weight of 8.82 ± 0.28 kg were distributed in a randomized block design composed of four treatments, with eight replicates per treatment and three animals per replicate. The treatments were as follows: PF1, SID Lys levels of 1.05, 0.95, and 0.85%; PF 2, SID Lys levels of 1.15, 1.05, and 0.95%; PF 3, SID Lys levels of 1.25, 1.15, and 1.05%; and PF 4, SID Lys levels of 1.35, 1.25, and 1.15% from 28 to 35, 36 to 49, and 50 to 63 d of age, respectively. From 28 to 63 d of age, the average daily feed intake (ADFI) and average daily gain (ADG) were not affected by the SID Lys levels tested; however, final body weight (fBW) was affected, with PF1 having the lowest fBW. The SID Lys levels tested had a significant effect on the feed conversion ratio (FCR), which varied linearly from 28 to 35 d of age. In the period from 28 to 63 d of age, pigs fed PF4 had the highest FCR results. The protein deposition ratio (PDR) was also affected by the SID Lys levels tested, with PF3 and PF4 having the highest PDR results. Therefore, the optimal SID Lys requirement for nursery pigs from 28 to 35 d of age that provided better performance results was 1.25%, corresponding to a daily Lys intake of 4.13 g/d. PF3 provided the best performance and PDR results for piglets from 28 to 63 days of age.