Detection of transgenic maize Cry1Ab protein subjected to ruminal digestion

J. L. Jacobs, F. Diez-Gonzalez, M. D. Stern, R. L. Phillips

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


This research determined the extent of ruminal degradation of a transgenic protein (Cry1Ab) expressed in kernels of maize (Zea mays) cultivar DKC53-32. Cracked kernels of transgenic maize (Bt+) were subjected to rumen digestion using in situ experiments with two ruminally cannulated Holstein cows. A non-transgenic maize cultivar (Bt-) was used as a control for crude protein (CP) degradation. CP and Cry1A concentrations from dacron polyester bags inserted in the rumen were determined for 48 h. The Bt- cultivar had greater CP content (P<0.05) than the Bt+ maize, but no difference (P>0.05) was found in ruminal degradable protein and the CP rate of degradation. The Cry1Ab protein was detected throughout ruminal digestion. The amount of Cry1Ab protein remaining after 16 and 24 h of ruminal degradation was 85 and 60%, respectively. These results indicated that a significant fraction of Cry1Ab protein was not digested in the rumen. This is the first report of the rumen degradation rate of a transgenic protein.

Original languageEnglish (US)
Pages (from-to)655-664
Number of pages10
JournalJournal of Animal and Feed Sciences
Issue number4
StatePublished - 2005


  • Bt maize
  • Cattle
  • Cry1Ab protein
  • Genetically modified
  • Rumen digestion
  • Zea mays


Dive into the research topics of 'Detection of transgenic maize Cry1Ab protein subjected to ruminal digestion'. Together they form a unique fingerprint.

Cite this