The aim of the experiment was to verify the effect of different doses of zinc nanocomplexes in farm conditions on the target category of livestock – piglets. The verification was carried out on 150 piglets in the production stable of the Institute of Animal Science. Two preparations based on nanocomplexes of zinc were verified, compared with ZnO and with a control group of piglets. During the verification, diarrhea or other signs of health disruption were monitored daily.