Effect of potassium diformate in combination with different amounts and sources of excessive dietary copper on production performance in weaning piglets.

Three studies with each 96 weaning piglets were conducted to evaluate the combinatory effect of potassium diformate and high dietary doses of Cu on production performance. In Exp. 1, increasing dietary Cu (25, 75, 125, 175 ppm Cu) were tested at either no or 1.8% potassium diformate. In Exp. 2, rising dietary levels of potassium diformate (0%, 0.6%, 1.2% and 1.8%) were tested at either 25 or 175 ppm Cu. In Exp. 3, a basal dietary Cu content of 15 ppm was compared with dietary Cu levels of 95 or 175 ppm, each of them added as either Cu sulphate or Cu amino acid chelate or Cu formate. Rising dietary additions of potassium diformate and Cu improved weight gain, feed intake and feed conversion rate of piglets. The combination of potassium diformate and Cu failed to act additively at highest dose levels of the two supplements. Cu sulphate was efficient as growth stimulating additive in all 3 experiments, Cu formate failed to stimulate production performance. Cu chelate tended to depress production performance and to increase blood plasma Cu compared to equivalent amounts of Cu from Cu sulphate.