Quality of Residue from GMO Corn vs. Non-GMO Corn | UNL Beef

Quality of residue from GMO corn vs non-GMO corn

The digestibility of the forage selected by cattle has not been found to differ between transgenic and the non-transgenic parent. Additionally, in five different trial with various genetic modifications to the corn plant, the gain of calves (supplemented with distillers grains or corn gluten feed) grazing transgenic vs the parental hybrid was not different (Table 1). In fact the numerical differences in gain appeared to correlate with the amount of dropped corn in the field rather than with genetic modification. Ear drop may explain why some producers have felt that Bt corn has a lower feeding value. In cases where there is corn borer pressure, the amount of dropped corn in non-Bt corn varieties may be greater resulting in greater feeding value for cattle grazing. However, this also means that less corn ended up going to market. Overall, quality of corn residue does not appear to be affect by Bt or round up read traits.

Table 1. Summary of five trials evaluating growing calf gain when grazing genetically modified (Bt or roundup ready) corn residue
		Calf gain, lb/d				Residual corn, bu/ac
Trial	Protein	TRAN	CON	Diff	P-value	TRAN	CON
Folmer, 2001	Bt (Cry1Ab)	0.54	0.7	-0.17	0.12	1	1.5
Wilson, 2003	RR (EPSPS)	1.28	1.05	0.23	0.07	2.3	1.6
Wilson, 2003	RR (EPSPS)	0.86	0.79	0.07	0.23	0	0.13
Wilson, 2003	Bt CRW (Cry3Bb1)	0.75	0.87	-0.12	0.31	0.29	0.58
Weber, 2011	Bt (Cry1A.105 + Cry2Ab2)	0.52	0.39	0.13	0.2	2.41	2.48

References

Folmer, J., G. E. Erickson, D. J. Jordon, T. Milton and T. J. Klopfenstein. 2001. Utilization of Bt Corn Hybrids in Growing Beef Steers. Nebraska Beef Report. p 30-41.

Russell, J. R., M. J. Hersom, M. M. Haan, M. Kruse, P. M. Dixon, D. G. Morrical and D. E. Farnham. 2001. Effects of grazing crop residues of Bt-Corn Hybrids on Performance of Pregnant Beef Cows. ISU Animal Science Research Reports. ASLR1745 p 32-41.

Weber, B. M., B. L. Nuttelman, W. A. Griffin, J. R. Benton, G. E. Erickson and T. J. Klopfenstein. 2011. Performance of Growing Cattle Fed Corn Silage or Grazing Corn Residue from Second Generation Insect-Protected (MON 89034), Parental, or Reference Corn Hybrids. Nebraska Beef Report p 16-17.

Wilson, C., C. Macken, G. Erickson, T. J. Klopfenstein, and E. Stanisiewski. 2003. Utilization of Genetically Enhanced Corn Residue on Grazing Steer Performance .Nebraska Beef Report p 18-19.