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Study of GM pig feed raising some eyebrows

Study of GM pig feed raising some eyebrows

*Krissa Welshans holds a bachelor's degree in animal science from Michigan State University and a master's degree in public policy from New England College. Welshans has long been involved in agriculture and has worked with numerous agricultural groups, including the Animal Agriculture Alliance.

A NEW study that was recently reported in the Journal of Organic Systems suggests that using genetically modified (GM) grains in pig feed is detrimental to the health of pigs.

The authors reported that pigs consuming GM grains showed a higher rate of stomach inflammation than pigs consuming non-GM feed. Additionally, the researchers suggested that the GM feed caused heavier uteri.

For almost 23 weeks, the researchers studied 168 pigs. From weaning to slaughter, half of the pigs were fed a GM corn and soybean ration, while the other half were fed non-GM corn and soybean ration. An equal number of male and female pigs were used in the study.

The researchers measured feed intake, weight gain, mortality and blood biochemistry. Additionally, organ weights and pathology were determined postmortem.

The researchers found no differences between pigs fed the GM and non-GM diets for feed intake, weight gain, mortality and routine blood biochemistry measurements. They did find, however, that the GM diet was associated with gastric and uterine differences in pigs.

The results showed that pigs fed the GM diet had 25% heavier uteri and higher rates of severe stomach inflammation — 32% versus 12% — than pigs fed the non-GM diet.

Upon further examination, the stomach inflammation results varied depending upon the degree of inflammation.

Mild stomach inflammation in both groups of pigs showed close to the same results: 23 pigs fed the GM diet versus 31 pigs fed the non-GM diet.

Moderate inflammation was observed in 18 pigs fed the GM diet and 29 pigs fed the non-GM diet.

Severe inflammation was found in 23 pigs fed the GM diet versus nine pigs fed the non-GM diet.

Stomach ulcer results varied based on the degree of inflammation but were similar for pigs on either diet.

What's interesting is that liver and heart conditions for pigs fed the GM diet were almost considered significantly better than for pigs fed the non-GM diet, but this was not showcased in the report.

The authors sought to study an animal similar to human beings in order to determine whether eating GM food could be detrimental to people.

The authors noted, "We not only used animals that were physiologically similar to humans, but we also weighed and internally examined organs and took blood for biochemical analysis."

The researchers added that they used a large enough sample size "to be able to determine statistical significance for key toxicological outcomes."

In response to the study, Dr. David Spiegelhalter, Winton professor of the public understanding of risk at the University of Cambridge, said, "The study's conclusions don't really stand up to statistical scrutiny. The authors focus on 'severe' stomach inflammation, but all the other inflammation categories actually favor the GM diet. So, this selective focus is scientifically inappropriate."

Additionally, he pointed out that when analyzed using appropriate methods, the stomach inflammation data do not show a statistically significant association with diet.

Because 19 other statistical tests have been reported, Spiegelhalter said it's expected that there would be one significant difference "just by chance." Because of this, he explained that the difference in uterus weight is more than likely a false positive.

What's also raising eyebrows is that at the end of the study, the authors said there are no conflicts of interest.

However, further digging implies otherwise.

The report says the research was funded by the Institute of Health & Environmental Research (IHER) and Verity Farms. Two of the three directors of the organization that funded the study were also researchers and authors of the study: The main researcher, Judy Carman, and another researcher, Catherine Clinch-Jones, are directors for IHER.

Verity Farms, with locations in Iowa, Georgia and South Dakota, had a vested interested in the study as well. Not only is the owner another one of the study's authors, but Verity Farms also sells non-GM meat, produce and grain products.

Additionally, Verity Farms said it sells "sustainable" water systems and fertilizer that align with its mission of reducing "input costs by correcting problems caused by the overuse of chemicals. Our products will help repair your soil, damaged by the excesses of modern-day farming."

The report's authors state that their study "reflects the effects of eating GM crops in the 'real world.'" The study, however, is being highly criticized by numerous swine experts, scientists and various media sources.


Delaying expansion

Although hog production has returned to breakeven levels, Purdue University Extension agricultural economist Chris Hurt advised producers to forego expansion for now because of delayed planting and uncertainty about this fall's corn harvest.

Pork producers were among some of the hardest hit financially when the drought of 2012 decimated grain supplies and sent feed prices skyrocketing, but hog prices have rallied this spring, from the mid-$50s/cwt. in March to the low-$70s, and feed prices have fallen somewhat on the heels of the U.S. Department of Agriculture's March "Grain Stocks" report that showed more grain supplies than expected.

Hurt said late spring planting has brought on some worries about hog production costs.

"Delayed planting has most recently sent corn and (soybean) meal prices trending upward, raising concerns that hog production costs will not drop as much as some had anticipated," Hurt explained.

Current production costs are about $67/cwt. on a liveweight basis. Hurt noted that hog prices for the third quarter are expected to remain about the same, leaving producers at breakeven levels for the foreseeable future.

Breakeven means that all of a producer's costs are covered, including depreciation and family labor. According to Hurt, most producers could continue their operations under breakeven conditions but are not likely to expand.

Corn and soybean meal prices are expected to decrease in late summer and into fall. Hurt said hog prices also would decrease, effectively perpetuating the breakeven trend.

"Current forecasts are that fourth-quarter corn prices will be $1.25 lower per bushel than third-quarter prices and that soybean meal prices will be $40 lower per ton," he said. "That means costs will drop from about $67 per live hundredweight this summer closer to $60 for the final quarter of the year.

"Hog prices are expected to be near the $60 level for the final quarter of 2013 and 2014, thus continuing breakeven conditions," he added.

Hurt advised producers to keep expansion plans on hold until they see how this year's crop sizes and prices pan out and how that will affect hog production costs. More information about the crop will become available over the next 60 days.

"In general, if corn prices stay below $6/bu., the pork industry will be able to survive another year of low crop production," Hurt suggested.

"Corn prices above $6 would push the outlook back to losses. The opposite would be true of $5 or lower corn prices," he added. "Some expansion could be expected with low $5 corn prices, and a more aggressive expansion would be expected with corn prices dropping below $5."

With that in mind, Hurt said expansion of the U.S. pork herd isn't likely until at least the fall. Any expansion at that time would begin with gilt retention and wouldn't increase pork supplies until the late summer and fall of 2014.

Volume:85 Issue:25

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