Too Much of a Good Thing: Rethinking Feed Formulation and Feeding Practices for Zinc in Swine Diets to Achieve One Health and Environmental Sustainability

Abstract

The objectives of this review were to summarize current knowledge of Zn in swine nutrition, environmental concerns, potential contribution to antimicrobial resistance, and explore the use of alternative feeding strategies to reduce Zn excretion in manure while capturing improvements in productivity. Zinc is a required nutrient for pigs but is commonly supplemented at concentrations that greatly exceed estimated requirements. Feeding pharmacological concentrations of Zn from ZnO to pigs for 1 to 2 weeks post-weaning reduces post-weaning diarrhea and improves growth performance. Feeding elevated dietary levels of Zn to sows during the last 30 days of gestation can reduce the incidence of low-birth-weight pigs and pre-weaning mortality. Most of the dietary Zn consumed by pigs is not retained in the body and is subsequently excreted in manure, which led several countries to impose regulations restricting dietary Zn concentrations to reduce environmental impacts. Although restricting Zn supplementation in swine diets is a reasonable approach for reducing environmental pollution, it does not allow capturing health and productivity benefits from strategic use of elevated dietary Zn concentrations. Therefore, we propose feeding strategies that allow strategic use of high dietary concentrations of Zn while also reducing Zn excretion in manure compared with current feeding practices.

Environmental risk assessment of the use of zinc oxide medicated feeds for weaning piglets in the UK

“…It is this need to balance the conflicting requirements of improved agricultural productivity and reduced environmental contamination that has caused some authors to recommend targeted mineral treatments at specific growth stages. 7 The present study assumed that all of the zinc consumed would be excreted, and whilst this is approximately correct, based on reported results, 6 it is slightly conservative and will lead to a small overestimation of zinc loadings to soils from this source because some zinc (<20%) is retained by the piglets.…”

Effects of a Phytogenic Feed Additive on Redox Status, Blood Haematology, and Piglet Mortality in Primiparous Sows

“…Minimising the oxidative stress of pigs in intensive production systems is essential for optimising health and productivity, which contributes to achieving pork production goals through One Health and environmental sustainability [105]. A more holistic approach should be considered in herd health management of modern high-profiling sows, using PFAs with antioxidant properties in the swine industry in a routine program.…”

Effects of a Natural Polyphenolic Product from Olive Mill Wastewater on Oxidative Stress and Post-Weaning Diarrhea in Piglets

“…Many studies have focused on investigating the most ideal prevention strategy for PWD. In view of the increasing resistance to antibiotics and the limitation of their use in pig diets [19,20], pig nutrition plays a key role in future prevention strategies [55,56]. For example, previous studies reported the beneficial effects of adding vegetable oils to weaners' diets against pathogens, including E. coli, which can cause gastrointestinal diseases [21,22].…”

“…The use of zinc oxide (ZnO) as a feed additive has been commonly proposed for the prevention of PWD in piglets. Based on recent regulations from 2022, the application of dietary ZnO in weaning feed has been forbidden in the European Union (EU) to reduce the negative environmental consequences of pig manure in agricultural soils [19]. Due to modern consumer demands and public health awareness, restrictions on the use of antibiotics as growth promoters in pig diets have also been proposed and applied [20].…”