CategoryAnimal Science - Swine Nutrition
Date Full Report Received04/23/2012
Date Abstract Report Received04/23/2012
Funded ByNational Pork Board
Objectives: To determine the nutrient content and lipid oxidation levels in DDGS samples from different sources and investigate the effects of feeding diets containing oxidized DDGS, with and without an antioxidant, on growth performance, health and immune status, nutrient digestibility, and metabolic oxidation balance in nursery pigs.
Procedures: The DDGS source used in this study was selected out of 31 DDGS sources produced by the ethanol plants in the U.S., and contained the highest thiobarbituric acid reactive substances (TBARS) value, peroxide value, and total sulfur content (5.2 ng/mg oil, 84.1 meq/kg oil, and 0.95%, respectively) among the other 30 DDGS sources sampled (mean values = 1.8 ng/mg oil, 11.5 meq/kg oil, and 0.50%, respectively). Fifty-four barrows were fed corn-soybean meal (CON) or 30% DDGS diets containing one of 3 levels of vitamin E (α-tocopheryl acetate): none supplemented (No-E), NRC (1X-E), or 10X NRC (10X-E) using a 3-phase nursery feeding program with targeted body weight of 7-11 kg, 11-25 kg, and 25-50 kg for Phase 1, 2, and 3, respectively. Barrows were housed in pens and fed the experimental diets for 8 wk after weaning and transferred to individual metabolism cages for collection of feces, urine, blood, and liver samples.
Findings: Total sulfur content was higher in DDGS diets than CON (0.39 vs. 0.19%). Dietary inclusion of 30% DDGS improved apparent total tract digestibility of sulfur (86.8 vs. 84.6%), as well as sulfur absorbed and retained compared to CON. Although pigs were fed highly oxidized DDGS in this study, serum TBARS were similar between DDGS and CON treatments. There was no interaction between dietary DDGS and α-tocopherol concentration in serum TBARS. Serum α-tocopherol (vitamin E) increased by feeding DDGS diets compared to CON (2.25 vs. 1.56 µg/mL). In addition, pigs fed DDGS diets had higher concentrations of sulfur-containing amino acids, particularly methionine and taurine in serum of fed pigs, and a higher concentration of taurine in serum of fasted pigs compared with those fed CON. Liver glutathione concentration was higher in pigs fed DDGS diets than CON (56.3 vs. 41.8 nmol/g). Dietary inclusion of DDGS and α-tocopherol increased serum enzyme activity of glutathione peroxidase.
Conclusions: The elevated concentrations of sulfur-containing antioxidants (methionine, taurine, glutathione) may protect pigs against oxidative stress when feeding highly oxidized DDGS. Therefore, increasing levels of α-tocopherol (vitamin E) in diets containing DDGS with high oxidized lipid content may not be necessary to protect pigs from metabolic oxidation stress.