Abstract
Total sulfur amino acids (TSAA): Lys level and Met source effects on growth performance and oxidative status were evaluated in nursery pigs fed oxidized soybean-oil. A total of 240 weaned pigs (BW=5.84± 0.96kg) were blocked by BW and randomly allotted to 60 pens. Treatments included a positive control containing fresh soybean-oil (PC) and 4 peroxidized soybean-oil treatments in a 2×2 factorial of 2 Met sources (DL-Met vs. 2-hydroxy-4-(methylthio)butanoate [HMTBa]) and 2 standardized ileal digestible TSAA: Lys levels (L1=0.58 vs. L2=0.65). Diets were fed for 42d. One pig per pen was euthanized at d42 for tissue analyses. Data were analyzed using PROC MIXED procedure of SAS. TSAA: Lys ratio did not affect ADG and ADFI. Met source did not affect ADG. HMTBa tended to increase ADFI compared to DL-Met (P = 0.08). There was a tendency for interaction between TSAA: Lys level and Met source for G: F (P = 0.07); pigs fed HMTBa-L1 tended to have decreased G: F compared to HMTBa-L2 and DL-Met-L1-L2. HMTBa had increased liver total antioxidant status (TAS) compared to DL-Met (P = 0.02). There was no TSAA:Lys level effect on TAS. Comparing PC to peroxidized treatments: pigs fed HMTBa-L1 and DL-Met-L1 tended to have decreased ADG (P ≤ 0.10) and DL-Met-L2 had decreased ADG (P < 0.05) than PC. HMTBa-L2 was similar to PC. Pigs fed DL-Met-L1 had decreased (P < 0.05) and DL-Met-L2 tended to have decreased ADFI (P ≤ 0.10) than PC. HMTBa-L1-L2 were similar to PC. All peroxidized treatments had similar G:F compared to PC. Pigs fed DL-Met-L2 tended to have decreased TAS compared to PC (P ≤ 0.10), but PC was similar to pigs fed DL-Met-L1 and HMTBa-L1-L2. In conclusion, under an oxidative challenge, HMTBa, at a TSAA: Lys ratio of 0.65, maintained nursery pigs’ growth performance and oxidative status.
Influence of supplemental lysine, isoleucine, threonine, tryptophan and total sulfur amino acids on egg weight of Hy-line W-36 hens