Digestibility of amino acids in distillers dried grains with solubles produced in Europe from wheat, maize, or mixtures of wheat and maize and fed to growing pigs

Abstract Text: European ethanol plants may use wheat or maize or combinations of wheat and maize as feedstock. The distillers dried grains with solubles (DDGS) produced, therefore, may vary in composition and nutritional attributes according to the grain that was used in the production.  There are, however, limited data on how these differences influence the digestibility of AA in DDGS. Therefore, an experiment was conducted to compare the standardized ileal digestibility (SID) of AA by growing pigs in European DDGS produced from wheat, maize, or wheat-maize mixtures. Twelve barrows (average initial BW: 23.0 ± 2.2 kg) were equipped with a T-cannula in the distal ileum and allotted to a replicated 6 × 6 Latin square design with 6 diets and 6 periods. The 5 sources of European DDGS that were used included wheat DDGS from 2011, wheat DDGS from 2012, wheat-maize DDGS (80% wheat and 20% maize), maize-wheat DDGS (70% maize and 30% wheat), and maize DDGS. A diet containing each source of DDGS as the sole source of AA was formulated and a N-free diet was used to determine basal endogenous losses of CP and AA. Results indicated that the SID of CP was greater (P < 0.05) in maize DDGS compared with wheat DDGS from 2011, wheat DDGS from 2012, and maize-wheat DDGS. The SID of all indispensable AA except Trp was also greater (P < 0.05) in maize DDGS compared with all other DDGS sources. For Trp, the SID in wheat-maize DDGS, wheat DDGS from 2011 and wheat DDGS from 2012 was not different from that of maize DDGS, but greater (P < 0.05) than in maize-wheat DDGS. The SID of all indispensable AA except Leu in maize-wheat DDGS did not differ from the values calculated for wheat DDGS from 2011 and wheat DDGS from 2012, and no differences between SID values for AA in wheat DDGS from 2011 and wheat DDGS from 2012 were observed. In conclusion, the SID of AA in maize DDGS produced in Europe is greater than in European wheat DDGS and DDGS produced from mixtures of wheat and maize. 

Keywords: amino acid digestibility, distillers dried grains with solubles, pigs