Beware the Myths of Feedlot Marketeers

11/10/2010 02:49 pm ET | Updated May 25, 2011

It's fair to say that intensive livestock farming is under the spotlight, and rightly so. Industrialized animal agriculture has a lot to answer for when it comes to its impact on animal welfare, the environment, and the livelihood of family farms.

But the likes of Smithfield and Monsanto aren't going to let go of their multi-billion dollar empires very easily. They want us to believe that modern mono-agriculture, with its industrial systems, GM crops and reliance on fossil fuels, is our only chance to stave off worldwide hunger. And they are doing their utmost to portray less intensive approaches to food production as inefficient, unscientific and even dangerous.

It has recently come to my attention that the National Beef Packing Company has given its distributors a revised version of an article (first published in January 2010 at by James E. McWilliams, entitled "Beware the Myths of Grassfed Beef," to help promote its "natural" beef products, and to counter the growing interest in grassfed beef.

I don't know who edited this newer version of the article. Perhaps McWilliams did it himself, or maybe someone at National Beef realized that if they printed the original article they would have found themselves promoting the animal welfare and health benefits of grass-fed beef over feedlot beef. Because McWilliams' original article states that "the comparative health benefits of grass-fed beef are well documented" and that grass-fed beef is "higher in omega 3s and lower in saturated fat" and "kinder to the animals." Yet all these points were removed from the version that National Beef is distributing. But let's not worry too much about that right now, because the real problem is the scientific foundation of McWilliams' article.

One of my pet peeves is deceit and spin being masqueraded as real science. So whenever I read these types of articles I always read the scientific reports and references they refer to in order to authenticate their claims. And all too often I find that the real science has been distorted or misrepresented.

McWilliams writes that "an Australian study found a higher prevalence of E. coli O157:H7 in the feces of grass-fed rather than grain-fed cows." Unfortunately, he provides no clear reference to substantiate this claim. However, I knew that another piece written about the comparative food safety of cattle fed hay vs. cattle fed grain (Hancock and Besser 2006) makes the following statement: "One study (Fegan et al, 2004a) found that a higher prevalence among pastured cattle and, among positive cattle, similar concentrations of E. coli O157:H7 in feces." Fegan is Australian, so this must be the study McWilliams is referring to. But if you read Fegan et al in detail, it says that "there was no significant difference (P = 0.06) between the numbers of E. coli O157 in pasture-fed or grain-fed cattle feces, although the geometric mean (antilog of the mean of log10 transformed MPN values) was higher in grain-fed (130 MPN g-1) than in pasture-fed (13 MPN g-1)." Leaving out all the "MPN g-1" jargon, this statement directly contradicts Mr. McWilliams' assertions: the science states that the level of E. Coli O157 is higher in grain-fed than in pasture-fed cattle.

McWilliams uses another Australian study (Fegan et al 2004b) to back up his claim that grassfed cattle become colonized with E. coli O157:H7 at rates nearly the same as grain-fed cattle. Again, when you read the full report, the researchers state that the "grassfed" cattle in the study may have been fed supplemental grain. Is this therefore a true comparison of grassfed and grainfed animals? Clearly not.

And how can someone who wants to refute claims that grassfed beef is safer have missed so much scientific evidence to the contrary? McWilliams fails to mention Barlow and Mellor's (2010) study which found that grainfed cattle are significantly more likely to have a higher concentration of E. coli in their feces than grass-fed cattle. Or Bailey and Vantelow (2003), who found that 58 percent of the feedlot cattle they tested were carrying the food poisoning campylobacter bacteria, while only 2 percent of cattle raised on pasture tested positive. Or Scott et al (1999) who switched cattle from grain-based diets to hay and found that acid-resistant E.coli decreased from 10,000 to 20 viable cells per gram in 7 days. The fact is that the scientific consensus indicates that more E. coli (including O157:H7) are present in the feces of cattle fed grain diets than forage-fed cattle. You'll find all the supporting evidence you need on the Animal Welfare Approved website blog.

It is more important than ever that we don't take such unfounded arguments at face value. Look at the research backing up the statements and consult trusted sources. The scientific reality is that grassfed systems do deliver higher animal welfare, environmental sustainability and improved nutritional qualities -- and a much lower risk of E. coli.