From the perspective of nutrition of livestock is plant production essential in the food chain. More than 80 % of plant matter produced on agricultural land enters via feeds to the food chain and is transformed into food products. To this process is related a high content of toxic substances in foods of animal production (more than 80 %), which comes from the feeds (presence of toxic substances from water, air, etc. is less frequent than from the feeds). Therefore is very important to realize agricultural practices, which should take into account feed and food safety.