A Safety Evaluation of Genetically Modified Feedstuffs for Livestock Production; the Fate of Transgenic DNA and Proteins

  • Beever, D.E. (Centre for Dairy Research (CEDAR), Department of Agriculture, The University of Reading) ;
  • Glenn, K. (Centre for Dairy Research (CEDAR), Department of Agriculture, The University of Reading) ;
  • Phipps, R.H. (Centre for Dairy Research (CEDAR), Department of Agriculture, The University of Reading)
  • Received : 2002.09.02
  • Accepted : 2003.01.08
  • Published : 2003.05.01


Two genetic constructs used to confer improved agronomic characteristics, namely herbicide tolerance (HT) in maize and soyabean and insect resistance (Bt) in maize, are considered in respect of feeding to farm livestock, animal performance and the nutritional value and safety of animal products. A review of nucleic acid (DNA) and protein digestion in farm livestock concludes that the frequency of intact transgenic DNA and proteins of GM and non-GM crops being absorbed is minimal/non existent, although there is some evidence of the presence of short fragments of rubisco DNA of non-GM soya in animal tissues. It has been established that feed processing (especially heat) prior to feeding causes significant disruption of plant DNA. Studies with ruminant and non-ruminant farm livestock offered GM feeds demonstrated that animal performance and product composition are unaffected and that there is no evidence of transgenic DNA or proteins of current GM in the products of animals consuming such feeds. On this evidence, current HT and Bt constructs represent no threat to the health of animals, or humans consuming the products of such animals. However as new GM constructs become available it will be necessary to subject these to rigorous evaluation.


  1. Beever, D. E and C. F. Kemp. 2000. Safety issues associated with the DNA in animal feed derived from genetically modified crops. A review of scientific and regulatory procedures. Nutr. Abstr. Rev. Series A 70: 197-204.
  2. Brake, J. and D. Vlachos. 1998. Evaluation of event 176 'Bt' corn in broiler chickens. J. Poultry Sci. 77:648-53.
  3. D'Mello, J. P. F. 1982. Utilization of dietary purines and pyrimidines by non-ruminant animals. Proc. Nutr. Soc. 41: 301-8.
  4. Folmer, J. D., R. J. Grant, C. T. Milton and J. F. Beck. 2000 Effect of Bt corn silage on short-term lactational performance and ruminal fermentation in dairy cows. J. Dairy Sci. 83:1182 (Abstract Mid West Branch).
  5. Henderson, J. F. and A. R. P. Patterson. 1973. Nucleotide Metabolism; an Introduction. Academic Press, London.
  6. James, C. 1999. Preview of the global review of commercialised transgenic crops 1999. ISAAA Briefs No. 12. The International Service for the acquisition of Agri-biotech Applications (ISAAA), Ithaca, New York.
  7. Khumnirdpetch, V., A. Udormsri Intarchote, S. Treemanee, S. Tragoonroong and S. Thummabood. 2001. Detection of GMOs in the broilers that utilised genetically modified soyabeanmeals as a feed ingredient. 9th Plant and Animal Genome Conf., San Diego, p585.
  8. McAllan, A. B. 1980. The degradation of nucleic acids in, and the removal of breakdown products from the small intestines of steers. Br.J.Nutr. 44:99-112.
  9. Padgette, S., N. Taylor, D. Nider, M. R. Bailey, J. MacDonald, M. R. Holden and R. L. Fuchs. 1996. The composition of glyphosate-tolerant soybean seed is equivalent to that of conventional soybeans. J. Nutr. 126: 702-716.
  10. Petty, A. T., K. S. Hendrix, E. P. Stanisiewski and G. F. Hartnell. 2001b. Performance of beef cattle fed Roundup Ready$\circledR$ corn harvested as whole plant silage or grain. Abstract 321 presented at the Midwestern Section ASAS and Midwest Branch ADSA 2001 Meeting, Des Moines, IA.
  11. Russell, J. R., M. J. Hersom, A. Pugh, K. Barrett and D. Farnham. 2000. Effects of grazing crop residues from Bt-corn hybrids on pregnant beef cows. Abstract 300 presented at the Midwester Section ASAS and Midwest Branch ADSA 2001 Meeting, Des Moines, IA.
  12. Russell, J. R., M. J. Herson, M. M. Haan, M. L. Kruse and D. G. Morrical. 2001. Effects of grazing crop residues from Bt-corn hybrids on pregnant beef cows. Abstract 300 presented at the Midwestern Section ASAS and Midwest Branch ADSA 2001 Meeting, Des Moines, IA.
  13. Rutzmoser, K. and J. Mayer. 2000. Milk yield and milk contents after feeding maize silage of strain 'Pactol' and the genetically modified Bt-Hybrid 'Pactol CB'. Proc. Joint Conference on 'Genetically Modified Organisms in the Food Chain'. Munich May, 2000. p.76.
  14. Sato, Y., M. Roman, H. Tighe, D. Lee, M. Corr, M-D Nguye, G. J. Silverman, M. Lotz, D. A. Carson and E. Raz. 1996. Immunostimulatory DNA sequences necessary for effective intradermal gene immunization. Science 273:352-354.
  15. Smith, R. H. 1975. Nitrogen metabolism in the rumen and the composition and nutritive value of nitrogen compounds entering the duodenum. In: Digestion and Metabolism in the Ruminant'. I. W. McDonald and A. C. I. Warner. (Ed.). pp 399-415. University of New England Publ. Unit, Armidale NSW, Australia.
  16. Beringer, J. E. 2000. Releasing genetically modified organisms: will any harm outweigh any advantage? J. Appl. Ecol. 37:207-214.
  17. Van Nevel, C. J. and D. I. Demeyer. 1977. Determination of rumen microbial growth in vitro from 32P-labelled phosphate incorporation. Br. J. Nutr. 38:101-14.
  18. Aulrich, K., R. Daenicke, I. Halle, H. Bohme and G. Flachowsky. 2001. Genetically modified feeds in animal nutrition. 1st Comm; Bacillus thuringiensis corn, Arch. Tierernahr. 54:183-195.
  19. Masood. 1998. Organic farmer takes gene battle to court. Nature, Lond. 394: 8.
  20. Schubbert, R., C. Lettman and W. Doerfler. 1994. Ingested foreign (phage M13) DNA survives transiently in the gastrointestinal tract and enters the bloodstream of mice. Mol. General Genetics 242:495-504.
  21. Bohme, H. and K. Aulrich. 1999. Inhaltsstoffe und Verdaulichkeit von transgenen Zuckerrben bzw. Krnermais im Vergleich zu den isogenen Sorten beim Schwein. (Ingredients and digestibility of transgenic sugar beets and corn in comparison to the isogenic varieties in the case of pigs). VDLUFA Conference Proceedings 1999, 111th VDLUFA Conference, 13-17 September 1999, Halle/Saale.
  22. FAO/WHO. 2000. Safety aspects of genetically modified foods of plant origin. Report of a Joint FAO/WHO Consultation, WHO, Geneva, Switzerland.
  23. Faust, M. A. 2000. Livestock products-Corn composition and detection of transgenic DNA/protein. In: Agricultural Biotechnology in the Global Marketplace. Joint ADSA/ASAS Symposium, Baltimore, USA. July 2000 (in press).
  24. Ash, J. A., S. E. Scheideler and C. L. Novak, 2000. The fate of genetically modified protein from Roundup Ready soybeans in the laying hen. Poultry Sci. Suppl. 1, p26.
  25. Einspainer, R., A. Klotz, J. Kraft, K. Aulrich, R. Poser, F. Schwagele, G. Jahreis and G. Flachowsky. 2001. The fate of forage DNA in farm animals: A collaborative case-study investigating cattle and chicken fed recombinant plant material. Europ. Food Res. Technol. 212:129-134.
  26. Borlaug, N. and C. Dowsewell. 2001. The unfinished Green Revolution – the future role of science and technology in feeding the developed world. Paper presented at the Seeds of Opportunity Conference, June 2001, London.
  27. Forbes, J. M., G. E. Blair, A. Chiter and S. Perks. 1998. Effect of feed processing conditions on DNA fragmentation. Scientific Report no 376, Ministry of Agriculture, Fisheries and Food, London, UK.
  28. Wehrmann, A., A. van Vliet, C. Opsomer, J. Botterman and A. Schulz. 1996. The similarities of bar and pat gene products make them equally applicable for plant engineers. Nature Biotech., 14:1274-1278.
  29. McAllan, A. B. 1982. The fate of nucleic acids in ruminants. Proc. Nutr. Soc. 41:309-317.
  30. Petty, A. T., K. S. Hendrix, E. P. Stanisiewski and G. F. Hartnell. 2001a. Feeding value of Bt corn grain compared with its parental hybrid when fed in beef cattle finishing diets. Abstract 320 presented at the Midwestern Section ASAS and Midwest Branch ADSA 2001 Meeting, Des Moines, IA.
  31. Razzaque, M. A. and J. H. Topps. 1972. Utilisation of dietary nucleic acids by sheep. Proc. Nutr. Soc., 31: 105A-106A.
  32. Aulrich, K., I. Halle and G. Flachowsky. 1998. Inhaltsstoffe und Verdaulichkeit von Maiskornen der Sorte Cesar und der gentechnisch veranderten Bt-hybride bei Legenhennen. Proc. Einfluss von Erzeugung und Verarbeitung auf die Qualitat laudwirtschaftlicher Pordukte. 46:5-8.
  33. Maeng, W. J. and R. L.Baldwin. 1975. Dynamics of rumen fermentation of a purified diet and microbial growth in the rumen. J. Dairy Sci. 59:636-642.
  34. Hendrix, K. S., A. T. Petty and D. L. Lofgren. 2000. Feeding value of whole plant silage and crop residues from Bt or normal corns. J. Anim. Sci. 78 (Suppl.1) p.273.
  35. Newport, M. J. and H. D. Keal. 1973. Artificial rearing of pigs. 10. Effects of replacing dried skim-milk by a single-cell protein (Pruteen) on performance and digestion of protein. Br. J. Nutr. 44: 161-170.
  36. Weber, T. E. and B. T. Richert. 2001. Grower-finisher growth performance and carcass characteristics including attempts to detect transgenic plant DNA and protein in muscle from pigs fed genetically modified 'Bt' corn. Midwestern Section ASAS and Midwest Branch ADSA Meeting, Des Moines, IA, Abstract #162.
  37. Sidhu, R. S., B. G.Hammond, R. L. Fuchs, J. N. Mutz, L. R. Holden, B. George and T. Olson. 2000. Glyphosate-tolerant corn: The composition and feeding value of grain from glyphosate-tolerant corn is equivalent to that of conventional corn (Zea mays L.). J. Agric. Food Chem. 48:2305-12.
  38. Clark, J. H. and I. R. Ipharraguerre. 2000. Livestock performance: feeding biotech crops. J. Dairy Sci. 84 (E suppl). E9-18.
  39. Donkin, S.S., C. J. Velez, E. P. Stanisiewski and G. F. Hartnell. 2000. Effect of feeding Roundup Ready corn silage and grain on feed intake, milk production and milk composition in lactating dairy cattle. J. Dairy Sci. 83 (Suppl 1):273 Abstract 1144.
  40. Phipps, R. H., D. E. Beever and D. J. Humphries. 2002. Detection of transgenic DNA in milk from cows receiving herbicide tolerant (CP4EPSPS) soyabean meal. Livest. Prod. Sci. 73: 269-273.
  41. Japan MAFF. 2000. No traces of modified DNA in poultry fed on GM corn. Nature, Lond. 409:657.
  42. Beever, D. E. and R. H. Phipps. 2001. The fate of plant DNA and novel proteins in feeds for farm livestock: a United Kingdom perspective. J. Anim. Sci., 79, (E suppl). E290-5.
  43. Daenicke, R., D. Gadeken and K. Aulrich. 1999. Einsatz von Silomais herk$\ddot{o}$mmlicher Sorten und der gentechnisch veränderten Bt Hybriden in der Rinderfhtterung-Mastrinder. 12th Maiskolloquium. pp.40-42.
  44. Halle, I., K. Aulrich and G. Flachowsky. 1998. Einsatz von Maisk$\ddot{o}$rnen der Sorte Cedar und des gentechnisch ver$\ddot{a}$nderten Bt-Hybriden in der Broiler mast. Proc. 5. Tagung, Schweineund Geflhgelernährung, December 1998, Wittenberg pp. 265-267.
  45. Hammond, B., J. L. Vicini, G. F. Hartnell, M. W. Naylor, C. D. Knight, E.H. Robinson, L. Fuchs and S. R. Padgette. 1996. The feeding value of soybeans fed to rats, chickens, catfish and dairy cattle is not affected by genetic incorporation of glyphosate tolerance. J. Nutr. 126:717-727.
  46. Howard, C. V. 2002. Statement presented to Advisory Committee on Release to the Environment (ACRE), Open Meeting, February 2002, London, UK.
  47. Mangen, J. L. 1982. The nitrogenous constituents of fresh forages. In: Forage Protein in Ruminant Animal Production. D. J. Thomson, D. E. Beever and R. G. Gunn. (Ed.). Br. Soc. Anim. Prod. Occas. Publ. 6:25-40.