EFFECT OF DIETARY ZINC INCLUSION ON THE PRODUCTIVE PERFORMANCE OF PIGLETS: META-ANALYSIS

Abstract

Zinc (Zn) is an essential element in the diet of pigs. However, there is variability in the levels, duration and sources of supplementation of this nutrient, which can generate uncertainty in swine nutritionists. The present meta-analysis was developed with the aim of evaluating the effect of dietary zinc inclusion on the productive performance of piglets. A total of 53 articles were included; effect size, heterogeneity and effect of moderators were determined using the random effects model. The results showed that inorganic zinc supplementation improved daily weight gain (+0.03581 kg day-1, p<0.00001), daily feed intake (+0.01868 kg day^-1, p=0.00001), feed conversion (-0.0554 kg kg^-1, p=0.00844) and feed efficiency (+0.03197 kg kg^-1, p<0.00001), with respect to the control group (without supplementation). The use of organic zinc improved daily weight gain (+0.0118 kg day^-1, p<0.00001), daily feed intake (+0.01697 kg day^-1, p=0.01266), and feed efficiency (+0.01923 kg kg^-1, p=0.01529). High heterogeneity values ??(>80%) were found in most of the variables evaluated, and thus meta-regressions were performed with the moderators: duration and level of zinc supplementation, and copper level. It is concluded that dietary zinc supplementation, from any source, favors the productive performance of piglets.