Effect of zinc source and picolinic acid on 65Zn uptake in an in vitro continuous-flow perfusion system for pig and poultry intestinal segments.

Twenty weanling pigs and fourteen 9-wk-old broiler chickens were used in three continuous-flow in vitro perfusion experiments using noneverted intestinal sacs to 1) determine differences in 65Zn absorption due to location within the intestinal tract, 2) evaluate 65Zn uptake from ZnCl2 and Zn-methionine (ZnMet) with or without added picolinic acid (PA) in pig intestinal sacs and 3) evaluate 65Zn uptake from ZnCl2 and ZnMet in chicken intestinal sacs. No differences in 65Zn uptake due to gut segment position were observed in the pigs. A Zn source x PA interaction was observed for 65Zn uptake into the pig gut tissue and for 65Zn uptake to the serosal side of the gut sacs. Total 65Zn absorption in the pig gut sacs from the two Zn sources was not different, but the addition of a 5 M ratio of PA to Zn depressed 65Zn absorption. No differences were observed in total 65Zn absorption or 65Zn uptake in poultry gut sac tissue. There was, however, greater uptake of 65Zn from ZnCl2 to the serosal side of the sacs than from ZnMet. The data indicate that 65Zn from ZnCl2 and ZnMet is similar in total absorption and that the addition of PA depresses Zn uptake.