Establishing the optimum cutting date and additives for pasture grass silage and its mycotoxin levels.

Abstract

Summary This study was aimed at determining most suitable cutting date and additives for pasture grass for ensiling and their mycotoxin residues. Grass samples were obtained at 24th June; 1st and 8th July. No additives, 5% ground barley or molasses additives silages were made. Silages opened 134 day after ensiling, and analysed for dry matter (DM), crude ash (CA), crude protein (CP), crude fibre (CF), NDF, ADF, ether extract (EE), pH, lactic acid (LA), acetic acid (AA), butyric acid (BA), total aflatoxin, aflatoxin B1 (AFB1), zearalenone. There were no statistical differences in CA and organic matter contents among the silage; however, there were differences in DM, CP, NDF, ADF, EE, nitrogen free extract, pH, LA, AA and BA. Mycotoxins residues were found in all fresh grass and silage samples. Total aflatoxin and AFB1 residues were generally above the acceptable limits in silages, but zearalenone residues were below. These findings suggest that the indicated times in our study are suitable for silage making, but the first two weeks of July is more proper due to the higher dry matter obtained, and best additive is 5% molasses provided that precautions against the fungi are taken in silages with molasses.