December 17, 2007

 

More DDGS research needed for cattle feed

 

 

Scientists at Kansas State University said further research is needed for dried distillers' grains with solubles (DDGS) as feed for cattle before reaching definitive conclusions.

    

In three separate studies conducted over the last two years, T.G. Nagaraja, a professor of microbiology in K-State's College of Veterinary Medicine, and Jim Drouillard, K-State professor of animal sciences and industry, found that feeding beef cattle a diet that included 25 percent DDGS increased the prevalence (number of cattle positive) of E. coli 0157 in those animals' manure.

 

The study shows that "in cattle, previous research has shown that the hind gut -- which consists of the cecum, colon, and rectum -- is the site of persistence of E. coli O157. Nagaraja said "cattle feed passes through the rumen before it reaches the hind gut".

 

Drouillard said that other universities also are studying this issue and that the research is far from finished.

   

Nagaraja said it is important knowledge that not all cattle have E. coli O157 and in fact, usually a relatively small percentage of cattle "carry detectable levels of this organism in their manure."

 

Drouillard added that DDGS do not also contain E. coli.

 

DDGS is a byproduct of the ethanol production process. A surge in ethanol production in recent years has led to increased availability of wet and dry distiller's grains, which have become a common ingredient in livestock and poultry rations. 

    

In the first of the three K-State studies, wet distiller's grain was fed to the test group of cattle. In the second and third studies, dry distiller's grains were fed. In all three studies, the cattle fed DDGS all had increased prevalence of E. coli O157 - approximately a two-fold increase.

 

Numerous questions remain to be answered in future studies, including the effect lesser amounts of DDGS would have on E. coli in cattle rations. 

 

The researchers said that there is no evidence to suggest that a recent increase in the number of meat recalls related to E. coli 0157 has any connection to the practice of feeding distiller's grains.  

 

Meanwhile, Nagaraja said K-state researchers are evaluating a vaccine that, if successful, could help manage

E. coli 0157 in cattle.

 

He said they are optimistic that the scientific community will be able to develop pre-harvest intervention strategies to manage E. coli O157.