May 21, 2010
French study finds wheat DDGS questionable for pig feed
French researchers investigated the ileal digestibility of amino acids in wheat DDGS and found that variability in lysine is of concern in using this raw material for inclusion in pig feeds.
In recent years, policies encouraging the production of ethanol from cereals have resulted in increased production of distillers dried grains with solubles (DDGS).
Unlike corn, nutritional value of DDGS and its variability for pigs is poorly described for wheat DDGS. 17 wheat DDGS samples were obtained from seven plants in Europe. Each sample was analysed for chemical composition and 10 representative samples were analysed for amino acids (AA) concentration and their standardised ileal digestibility (SID) in pigs.
Luminance (L) of the DDGS was also measured. Results indicate a rather stable crude protein concentration (326-389 g/kg DM; average: 361 g/kg DM) but the AA profile was variable among samples.
Lysine (lys) concentration was the most variable with values ranging between 0.83 and 3.01 g/100 g CP. Only 76% to 85% of total lysine was available depending on the procedure used for measuring (fluoro dinitro benzene resp. furosine procedure). The SID of lysine was also highly variable (0.09–0.83) with the lowest values observed for the three samples that had a low lysine concentration in CP.
These latter samples also had a high occurrence of Maillard reaction products and low L values.
Consequently, both lys:CP and SID of lys were positively related with L. The data indicates that lys SID can be accurately predicted from lys:CP. The SID of other AA was less variable than that observed for lysine.
The results of the current trial indicate that variability in lysine concentration and its SID represent a major concern when wheat DDGS are fed to pigs. The combination of low lysine content in CP and low SID of lysine in dark DDGS suggests not including such type of ingredient in feeds for pigs.
