EN
The aim of the investigations was to experimentally determine the effect if high ZnO doses, applied in feed, on the clinical condition of experimental piglets and effectiveness of a such procedure for prophylaxis of piglet diarrhoea in the weaning period. 108 Landrace piglets, weaned at the age of 6 weeks, were used for experiments. Out of this group 88 piglets were used for clinical observations and estimation of body weight gains. The remaining 20 piglets were used for laboratory experiments to determine ZnO doses on serum and tissue Zn levels. During the first 63 days daily body weight gains in piglets which were given the feed supplemented with 2500 ppm ZnO were 291 grams. In the controls this value was 285 g. Mean body weight of experimental piglets was 280 g higher on the 63rd day of life than that found in control piglets. In litters of experimental animals which received feed supplemented with 3000 ppm ZnO the mean daily body weight gain was 26 g higher than that in control animals. A favourable effect of Zn addition was found in piglets receiving feed with the addition of 3500 ppm ZnO. Daily weight gains in experimental piglets were 47 g higher than those in control animals. No negative clinical effects were found in experimental piglets receiving increased ZnO doses. Prophylactic application in feed of high ZnO doses (ranging from 2500 to 3500 ppm (2000-2800 ppm Zn)) for 21 days proved to be safe for piglets. The administration of a high level of ZnO for 7 days before weaning and 14 days after weaning decreases the occurence of diarrhoea in the weaning period and limits the reduction of body weight gains caused by diarrhoea. The level of Zn in serum and tissues of 180-day-old slaughtered pigs was similar to those detected in control pigs.