Productivity and the presence of mycotoxins in oats, wheat, and triticale subjected to grazing

Abstract

This study aimed to evaluate the effects of grazing on the agronomic characteristics, grain yield, and presence of the mycotoxins aflatoxins, fumonisins, and zearalenone in IPR 126 oat, BRS Tarumã wheat, and IPR 111 triticale. This study was performed from April 24, 2012 to November 11, 2013 at UNIOESTE's Experimental Farm in southern Brazil. The experimental design was a randomized block in a banded scheme, with four replications. The treatments in the A tracks were the three crops and the B tracks, the treatments: without grazing, one grazing event, or two grazing events. One grazing reduced the productivity of oat by 42.48% and triticale by 28.09% and increased wheat productivity by 24.89%. Two grazings reduced oat productivity by 54.14%, wheat by 40.96%, and triticale by 54.69%. Crops subjected to two grazings should be used for dry matter production for ground cover or partially used for silage when the plant is in the pasty or semi-hard grain stage, as grazing affects the agronomic characteristics and grain yield. The BRS Tarumã wheat, when used in crop-livestock integration systems, should be grazed only once due to increased productivity, while IPR 126 oat and IPR 111 triticale should not be grazed in crop-livestock integration systems for commercial production of grain. Oats from grazed plants should not be added to feeds of poultry in the early stage or pigs in the early and growth stages due to the higher levels of aflatoxins, fumonisins, and zearalenone. Grazing of winter crops increases the length of the crop cycle and grain formation will occur under climatic conditions favorable to the mycotoxins. Therefore, when grains are intended for human consumption, grazing is not recommended, as it increases the possibility of aflatoxins, fumonisins, and zearalenone at levels above the maximum tolerable levels permitted by law. These grains should be supplied to animals only after analysis of the mycotoxin levels present in the grains.