Many of us wonder about the safety of the food we eat. We’ve answered questions about genetically-modified food, but recently, Best Food Facts received a question via Twitter, asking if GM feed is linked to poor fertility in farm animals, particularly poultry and waterfowl.
To answer this question, we reached out to Dr. Wayne Parrott and Dr. Bruce Chassy.
Dr. Wayne Parrott
Dr. Wayne Parrott: ”This is an important question, given that pretty much all the poultry and hogs raised in the U.S. are done so on GM grain, and such has been the case for several years. Furthermore GM grain is important to fatten cattle. The bottom line is that if GM grain affected fertility even a little bit, it would have caused widespread havoc across the animal industries.
“Having said that, I have no doubt your questioner has witnessed loss of reproductive ability in livestock, but might have jumped the gun a bit in assuming damage was due to GM. Any two sources of livestock feed will always differ by more than just being non-GM or GM. The variety planted, the way and time it was stored, where it was grown and lots of other variables all affect the final product. For example, something as simple as mold growth during storage could affect animal fertility, regardless of whether the grain is GM or not. The fact remains that when feeding tests are done comparing GM grain to non-GM grain, where everything that might affect the outcome is carefully controlled, no one has seen any loss of reproductive ability.”
Dr. Bruce Chassy
Dr. Bruce Chassy: “As Dr. Parrott points out, many factors could affect fertility in animals. Without a direct test in which the questioner’s GM and non-GM grains were compared and ALL other variables were held constant, one should not leap to a conclusion that any single factor caused infertility. The process of unraveling what was the cause requires careful analysis and a good deal of detective work. The veterinary college and/or the animal science department at the nearest land grant university can often be of great help in identifying the cause of adverse effects.
“GM crops are tested extensively in production animals of all kinds before they are released for commercialization. They must perform equivalently (or better) to their conventional counterparts or they are not approved. Overall animal production in the U.S. has continued a small but steady increase each year since the introduction of GM crops. Animal feeds are now almost exclusively GM grains so adverse effects on reproduction should have been evident by now, but there is no such trend.”
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