What are GMO crops?
Holistic Horse
Horse eating off the ground
Horse eating off the ground
GMO stands for Genetically Modified Organism. Genetically modified organisms have had specific segments of DNA placed in their innate DNA. The objective is to give the organism a desirable trait (resistance to pests, disease, or specific chemicals). The term “genetically engineered” is often used interchangeably with “GMO.” This has led to confusion since genetically engineered is also used to describe plants and animals that have been developed via natural selection. For example, the modern horse can be considered a genetically engineered organism since it has been developed through selective breeding of individuals that have displayed “desirable” characteristics (speed, temperament, agility, cow sense, jumping ability, etc.). The term “GMO” in this article indicates crops that have had their DNA intentionally altered with otherwise foreign DNA segments.
Adaptation of GMO crops
The US has led the world in regard to the rate at which GMO crops have been adapted in commercial agriculture. The EU tends to place more restrictions on commercially available GMO crops and has been slower to use them in commercial agriculture. Animal feed and ingredients containing GMOs are imported into the EU on a country-by-country basis. GMO varieties of corn, soybeans, papaya and cotton make up the majority of GMO crops currently being grown commercially.
Effects of GMO feeds on animals
Studies published in scientific journals have examined the effect and safety of feeding GMO diets to livestock. It is difficult to say exactly how many studies have shown absolutely no difference between GMO diets and non-GMO diets, but it is safe to say that greater than 98 percent of studies reported in scientific journals have
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Horse feed tag
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Holistic Horse
Horse eating off the ground
Horse eating off the ground
demonstrated that GMO diets fed to growing and reproducing livestock resulted in no change in health or performance including histological examination of internal organs (Snell et al, 2012).
However, this may not be the total story. Research investigating the effect of GMO diets on the microbiota of animals indicates that there may be a difference between GMO diets and GMO-free diets, Any changes in microbiota in the digestive tracts of animals fed GMO diets appears to be more of an effect of the herbicides used on the GMO crops and not a result of the GMO ingredients themselves. Shehata et al. reported in Current Microbiology that glyphosate (the active ingredient in Roundup), which is used on GMO crops to reduce competitive weeds has a negative effect on Enterococcus faecium, which is recognized as being one of the more important bacteria in the digestive tracts of animals and humans. Additionally, other studies have reported that commercial forms of Roundup (glyphosate plus surfactant) may reduce the number of beneficial bacteria and increase the number of pathogenic bacteria in the digestive tract of animals (Kruger et al). One study in particular (Kim et al) reported that glyphosate in combination with surfactant had negative effects on cell mitochondria whereas glyphosate or surfactant individually did not. Research with GMO corn containing a gene that makes it resistant to pests has not demonstrated any effects on digestive tract microbiota or mitochondrial damage, further indicating that any negative effect of feeding GMO feeds may be more related to herbicide applications than the actual GMO ingredient.
What about GMOs and allergies?
Research with GMO crops have indicated that changes in protein structure of the GMO crop do not result in allergic reactions in the majority of individuals ingesting them, however, it cannot be stated that 100 percent of the animals ingesting a GMO crop will not have an allergic reaction since the susceptibility to any allergen is also mediated by the specific genetics and biochemical composition of each individual.
What does this mean for my horse?
Certain horses may experience changes in their digestive tract microbiota, which in turn can mediate changes in immunity and insulin resistance. Horses presenting with allergies, poor weight control (too thin or too fat), insulin resistance, chronic ulceration, or intestinal inflammation may benefit from a GMO-free diet. Clinical evidence suggests that if a horse is negatively affected by consuming GMO ingredients it will respond in a positive manner within 30 days when receiving a GMO-free diet. Keep in mind that there are many factors that can cause an individual horse to present with these symptoms, and a switch to a GMO-free diet does not guarantee positive results.
Horse owners that have switched to a GMO-free diet due to unsatisfactory performance or health concerns have reported one or more of the following improvements:
- improved attitude and energy
- reduced fat deposition patterns in over-weight horses
- improved digestive function (loose manure changing to “road apples”)
- improved weight maintenance in hard keepers on less feed
Dr. Vandergrift obtained his PhD in animal nutrition from Texas A&M University in 1980 and then held a teaching and research position at the University of Georgia from 1981 until 1984 where he taught courses in Principles of Nutrition, Vitamin Nutrition, Feeds and Feeding, and Horse Production. EquiVision www.equivision.com now manufacturers over 15 products based on research and results.
References:
Assessment of the health impact of GM plant diets in long-term and multigenerational animal feeding trials: A literature review, Chelsea Snell, Aude Bernheim, Jean-Baptiste Bergé, Marcel Kuntz, Gérard Pascal, Alain Paris, Agnès E. Ricroch, 2012, Food and Chemical Toxicology vol 50:1134-1148.
The effect of glyphosate on potential pathogens and beneficial members of poultry microbiota in vitro. Shehata AA, Schrödl W, Aldin AA, Hafez HM, Krüger M. Curr Microbiol. 2013 Apr;66(4):350-8.
Mixtures of glyphosate and surfactant TN20 accelerate cell death via mitochondrial damage-induced apoptosis and necrosis. Kim YH, Hong JR, Gil HW, Song HY, Hong SY. Toxicol In Vitro. 2013 Feb;27(1):191-7.
Multiple organ histopathological changes in broiler chickens fed on genetically modified organism. Cîrnatu D, Jompan A, Sin AI, Zugravu CA. Rom J Morphol Embryol. 2011;52(1 Suppl):475-80.
Glyphosate suppresses the antagonistic effect of Enterococcus spp. on Clostridium botulinum. Krüger M, Shehata AA, Schrödl W, Rodloff A. Anaerobe. 2013 Apr;20:74-8.