Effect of Ustilago maydis on the Nutritive Value and Aerobic Deterioration of Maize Silage

Abstract

The common smut of corn, caused by Ustilago maydis, reduces the yield and quality of maize forage. When heavy infestations of corn smut occur, grain yields can be so severely decreased that the most viable economic alternative may be to harvest and ensile the crop. Only a couple of studies have attempted to investigate the influence of aerobic exposure on the nutritive value and aerobic stability of silage, which is prepared from smut-infected maize. In this study, individual whole corn plants were harvested by hand. The plants were distributed into three treatments: 0% infected, 50% infected, and 100% infected. The fresh forage was ensiled in triplicate for a 90-day period. Aerobic exposure lasted for 28 days. Samples were taken on the day of opening and on the 3rd, 7th, 14th, and 28th days. Near infrared spectroscopy (NIRS) calibration equations were used for the prediction of qualitative indicators. Silage prepared from 100% smut-infected maize had comparatively poor quality with dry matter loss, increasing pH and the low amount of starch. It was also distinguished with significant temperature increases from days 15 to 18 of aerobic exposure. Silage prepared from 50% smut-infected maize did not show significant quality changes over the period of the experiment, although it had inferior quality compared to the silage prepared from smut-free maize. While silage prepared from smut-infected maize had an overall worse quality than silage prepared from non-infected maize, it should not have an adverse effect on livestock health or production.