Nutritive value of the crop residues from bt-corn hybrids and their effects on performance of grazing beef cows. Beef Research Report -Iowa State University. Herbicide -Tolerant Corn Petty, A.T., K.S. Hendrix, E.P. Stanisiewski and G.F. Hartnell. Performance of beef cattle fed Roundup Ready corn harvested as whole plant silage or grain. Insect - Protected Corn Faust, M. and L. Miller. 1997.
Study finds no Bt in milk.
Fall Special Livestock Edition. Iowa State University Extension, Ames, Iowa. R.J. Grant, C.T. Milton and J.F. Beck. Effect of Bt corn silage on short-term lactational performance and ruminal fermentation in dairy cows. J. Dairy Sci.