My i year old heifer grazes in a field (Northern AZ) which has fescue in it. She also recieves alfalfa hay and grain every day. Am I putting her at risk for fescue toxicity? She grazes in the field about 3 hours ea. morning and 4 hours ea. evening. Fescue is the kind of grass we have out here besides your general weeds. She has been grazing in this field most of the year.