A number of long-term (of more than 90 d and up to 2 years in duration) feeding trials and multigenerational studies conducted by public research laboratories using various animal models including pigs, cows, quail, and fish have also been reviewed (Ricroch, 2013; Ricroch et al., 2013; Snell et al., 2012). Significant among these studies are two thorough multigenerational studies that examined the long-term effects of feeding a genetically engineered (GE) corn variety (MON810, expressing the insecticidal Cry1Ab protein from Bacillus thuringiensis [Bt], one of the few GE corn varieties approved for cultivation in the EU) to food-producing animals, specifically, a German study in dairy cattle and an Irish study in pigs. These studies were notable in that they included appropriate controls consuming isogenic non-GE lines of corn, and both comprehensively examined a range of phenotypes and indicators of growth and health and also used sophisticated techniques to look for the presence of recombinant DNA (rDNA) and Bt protein in the tissues and products derived from these GE-fed animals (Guertler et al., 2010, 2012; Steinke et al., 2010; Walsh et al., 2011, 2012 a, b, 2013; Buzoianu et al., 2012 a, b, c, d, 2013 a, b)
- Buzoianu, S. G., M. C. Walsh, M. C. Rea, J. P. Cassidy, R. P. Ross, G. E. Gardiner, and P. G. Lawlor. 2012a. Effect of feeding genetically modified Bt MON810 maize to approximately 40-day-old pigs for 110 days on growth and health indicators. Animal 6: 1609-1619.
- Buzoianu, S. G., M. C. Walsh, M. C. Rea, J. P. Cassidy, T. P. Ryan, R. P. Ross, G. E. Gardiner, and P. G. Lawlor. 2013a. Transgenerational effects of feeding genetically modified maize to nulliparous sows and offspring on offspring growth and health. J. Anim. Sci. 91: 318-330.
- Buzoianu, S. G. et al. 2012b. Effects of feeding Bt maize to sows during gestation and lactation on maternal and offspring immunity and fate of transgenic material. PLoS One 7: e47851.
- Buzoianu, S. G., M. C. Walsh, M. C. Rea, O. O'Sullivan, P. D. Cotter, R. P. Ross, G. E. Gardiner, and P. G. Lawlor. 2012c. High-throughput sequence-based analysis of the intestinal microbiota of weanling pigs fed genetically modified MON810 maize expressing Bacillus thuringiensis Cry1Ab (Bt maize) for 31 days. Appl. Environ. Microbiol. 78: 4217-4224.
- Buzoianu, S. G., M. C. Walsh, M. C. Rea, O. O'Sullivan, F. Crispie, P. D. Cotter, R. P. Ross, G. E. Gardiner, and P. G. Lawlor. 2012d. The effect of feeding Bt MON810 maize to pigs for 110 days on intestinal microbiota. PLoS One 7: e33668.
- Buzoianu, S. G., M. C. Walsh, M. C. Rea, L. Quigley, O. O'Sullivan, P. D. Cotter, R. P. Ross, G. E. Gardiner, and P. G. Lawlor. 2013b. Sequence-based analysis of the intestinal Microbiota of sows and their offspring fed genetically modified maize expressing a truncated form of Bacillus thuringiensis Cry1Ab protein (Bt Maize). Appl. Environ. Microbiol. 79: 7735-7744.
- Guertler, P., C. Brandl, H. D. Meyer, and A. Tichopad. 2012. Feeding genetically modified maize (MON810) to dairy cows: comparison of gene expression pattern of markers for apoptosis, inflammation and cell cycle. Journal für Verbraucherschutz und Lebensmittelsicherheit 7: 195-202.
- Guertler, P., V. Paul, K. Steinke, S. Wiedemann, W. Preißinger, C. Albrecht, H. Spiekers, F. J. Schwarz, and H. H. D. Meyer. 2010. Long-term feeding of genetically modified corn (MON810) — Fate of cry1Ab DNA and recombinant protein during the metabolism of the dairy cow. Livestock Science 131: 250-259.
- Ricroch, A. E. 2012. Assessment of GE food safety using '-omics' techniques and long-term animal feeding studies. N. Biotechnol. 30:349-354.
- Ricroch, A. E., A. Berheim, C. Snell, G. Pascal, A. Paris, and M. Kuntz. 2013. Long-term and multi-generational animal feeding studies. In: G. Flachowsky (ed.) Animal nutrition with transgenic plants No. 1. p 112-127. CABI Biotechnology Series, Oxfordshire, UK.
- Snell, C., A. Bernheim, J. B. Berge, M. Kuntz, G. Pascal, A. Paris, and A. E. Ricroch. 2012. Assessment of the health impact of GM plant diets in long-term and multigenerational animal feeding trials: a literature review. Food Chem. Toxicol. 50: 1134-1148.
- Steinke, K., P. Guertler, V. Paul, S. Wiedemann, T. Ettle, C. Albrecht, H. H. Meyer, H. Spiekers, and F. J. Schwarz. 2010. Effects of long-term feeding of genetically modified corn (event MON810) on the performance of lactating dairy cows. J. Anim. Physiol. Anim. Nutr. (Berl) 94: e185-193.
- Walsh, M. C., S. G. Buzoianu, G. E. Gardiner, M. C. Rea, E. Gelencser, A. Janosi, M. M. Epstein, R. P. Ross, and P. G. Lawlor. 2011. Fate of transgenic DNA from orally administered Bt MON810 maize and effects on immune response and growth in pigs. PLoS One 6: e27177.
- Walsh, M. C., S. G. Buzoianu, G. E. Gardiner, M. C. Rea, O. O'Donovan, R. P. Ross, and P. G. Lawlor. 2013. Effects of feeding Bt MON810 maize to sows during first gestation and lactation on maternal and offspring health indicators. Br. J. Nutr. 109: 873-881.
- Walsh, M. C., S. G. Buzoianu, G. E. Gardiner, M. C. Rea, R. P. Ross, J. P. Cassidy, and P. G. Lawlor. 2012a. Effects of short-term feeding of Bt MON810 maize on growth performance, organ morphology and function in pigs. Br. J. Nutr. 107: 364-371.
- Walsh, M. C., S. G. Buzoianu, M. C. Rea, O. O'Donovan, E. Gelencser, G. Ujhelyi, R. P. Ross, G. E. Gardiner, and P. G. Lawlor. 2012b. Effects of feeding Bt MON810 maize to pigs for 110 days on peripheral immune response and digestive fate of the cry1Ab gene and truncated Bt toxin. PLoS One 7: e36141.