And Gerhard Flachowsky, scientist with the Institute of Animal Nutrition in Braunschweig in Germany and former EFSA GMO Panel member, said while conventional and genetic breeding technologies may both contribute to the production of high yield crops that need low inputs of non-renewable resources such as water, fuel, arable land, and fertilizers, the genetic engineering approach may be faster and more precise (Tester and Langridge, 2010).
However, the researcher, writing in Feedipedia, said: “All methods of plant breeding that lead to an increase in resource efficient production and a stable yield of available biomass should be used or combined.”
He cited extensive reviews of peer-reviewed literature on food producing animals fed diets containing GMP-feed (Van Eenennamm and Young 2014 and Flachowsky 2013) that indicated no unexpected perturbations or disturbing trends in animal performance or health indicators.
The article noted the global area used for the cultivation of GMPs increased from 1.6 million hectares (ha) in 1996 to 181.5 million ha in 2014. GMPs then take up about 12% of arable land and, in the main, consist of soybean, maize, cotton and rapeseed. Flachowsky said such cultivation is dominated by ‘first generation’ GM plants.
First generation GMPs are considered ‘substantially equivalent’ to their isogenic counterparts because they do not exhibit substantial differences in their composition or their nutritional value.
Most animal studies have been done using these ‘first generation’ GMPs, which are characterized by input traits such as tolerance to pesticides or herbicides, or resistance against insects, he said.
Second generation GM plants
But the German animal nutrition scientist, presenting at the GMSAFOOD conference in Vienna, Austria in 2012, did question whether more feeding studies to assess the nutritional and safety of GM plants with substantial changes in composition – the so-called second generation GMPs – were required.
Second generation GMPs are characterized by output traits such as an increase in valuable compounds like amino acids, fatty acids, vitamins, or enzymes, an improved availability of nutrients, or a decreased concentration of undesirable substances such as phytate, lignin, or allergenic substances.
Some examples of such 'biofortified' GMPs under development are a rice rich in beta-carotene, and a maize high in lysine as well as a maize low in phytate (Tillie et al 2013), noted Flachowsky.
“There is no urgent need for biofortification in developed countries from the animal nutrition perspective, because many feed additives are available for use in animal rations. On the other hand, biofortified plants, as well as plants which use limited resources efficiently may substantially contribute to nutrition and food security of smallholders in many developing countries (Ruane et al 2013 and Harvie 2015),” he said.
Alison van Eenennamm, geneticist at the Department of Animal Science at the University of California, said second generation GE crops will by definition not be ‘substantially equivalent’. "Whether this represents a safety concern will depend on the trait,” she said.
Writing in the Journal of Animal Science and Biotechnology in 2013, van Eenennamm said research may be needed to assess the bioavailability or digestibility of nutrients, and the efficacy of nutrient uptake from second generation GE crops. She said that standard protocols outlining best practices for the conduct of animal studies to evaluate crops genetically modified for output traits have been developed.