Metabolomic analysis of GM and non-GM maize and its preference by cattle

Abstract

GM organisms have started to infiltrate South Africa's agricultural landscape, altering how farmers deal with weeds and insects. Adopted from the United States of America, it is a technology that the commercial farming sector cannot do without anymore and the uptake was enormous in the last 10 years. The technology involves altering the DNA of an organism to provide a specific benefit using genetic engineering techniques. But all new technologies and inventions bring the responsibility of stewardship and accountability with it, and it is impossible to predict all possible outcomes of such an invention to every possible scenario in terms of environmental stewardship. The question and occurrence of cattle and wild animals seemingly choosing non-GM containing maize plants have raised the question whether this is really the case of the presence of the GM or maybe it is just due to the differences in plant genetic makeup. Quicker deterioration of short, seasoned cultivars opposed to the longer seasoned cultivar that is known to be more resistant to diseases and plant pathogens, might therefore not be as easily affected by mainly pathogens and stay much tastier for longer. This study used beef cattle of the Drakensberger indigenous breed to determine the taste preference with the use of a trial that is planted with the different types of maize cultivars that includes GM and non-GM maize and short and longer seasoned cultivars. The trial was performed on a commercial farm near Standerton, Mpumalanga in the high rainfall area of South Africa. The results clearly indicated that cattle could not differentiate the GM maize from the non-GM maize, but that they preferred the longer season cultivar. The chemical profiles of different materials, including those made from GM and non-GM, were analyzed using NMR spectroscopy and OPLS-DA and pre-processing techniques. The results of the metabolomic study revealed that the former had slightly different metabolomics profiles than the latter. The differences were mainly concentrated in the aliphatic and sugar regions. On the other hand, the long and short-season GM had similar metabolomic profiles. The study therefore clearly indicates that cattle could not differentiate GM from non-GM material on taste and that any material can be provided to cattle. The slight difference in the metabolomics profiles however raise a concern for differential metabolomic pathways and should be investigated further.