Nutritional efficiency of genetically-modified insect resistant corn [MON 810] and glyphosate-tolerant soybean meal [Roundup Ready] for broilers

The aim of this study was to evaluate the effect of genetically-modified (GM) insect-resistant corn (MON 810) and glyphosate-tolerant GM soybean meal (Roundup Ready, MON 40-30-2), used as the main dietary components for broilers, on the performance parameters, results of slaughter analysis, and the chemical composition of the breast muscles. In a 42-d floor pen experiment, Ross 308 broilers were fed corn-soybean meal diets. In the experiment, a randomised complete block design was used with 4 dietary treatments. Each treatment was divided into 4 replicates (pens) of 40 birds. All the experimental diets met the requirements of broilers; they were all isonitrogenous and isoenergetic, and contained non-modified corn and soybean meal (group I), non-modified corn and GM soybean (group II), GM corn and non-modified soybean meal (group III), or GM corn and GM soybean meal (group IV), respectively. The nutrient composition of Bt corn and its non-modified isogenic counterpart (parental line) revealed no major differences. The final live weight, average daily weight gain, feed intake, feed conversion (feed:gain ratio), and mortality rate did not differ statistically across the dietary treatments. No statistical differences (P>0.05) were also found in the results of slaughter analysis (carcass yield, meat yield, abdominal fat pad, and relative weight of the liver, gizzard, and spleen) and chemical composition of the breast muscles. It was concluded that insect-resistant GM corn (MON 810) and soybean meal produced from glyphosate-tolerant GM soybean (Roundup Ready) are nutritionally equivalent to conventional feeds and can be used as components of broiler diets with no adverse effect on performance indices.