November 20, 2020


Hydroxychloride minerals can improve swine performance at levels below EU regulations: Trouw Nutrition



In-vitro and in-vivo research studies published in the Journal of Animal Physiology and Animal Nutrition show supplementing diets of grower-finishing pigs with  hydroxychloride sources of zinc (Zn) at levels below EU regulatory levels can support improved growth performance and carcass characteristics compared to sulphate sources.

From an environmental perspective, the researchers also found that swine receiving hydroxychloride sources of copper at nutritional levels, excreted less copper into the environment compared to swine fed sulphate sources at the same nutritional level. The findings suggest an opportunity for swine nutritionists and farmers to address both environmental and antimicrobial resistance concerns associated with livestock production and the use of copper in animal feed.

Specifically, researchers compared the source (hydroxychloride or sulphate) of zinc supplementation and the level (20 mg/kg Zn as a low level and 80 mg/kg Zn as a nutritional level), evaluating effects on growth performance, carcass characteristics, mineral content and mineral apparent total tract digestibility in grower-finishing pigs reared under commercial conditions. Copper was fixed at 15 mg/kg in all diets, using the same source as the supplemented Zn in each diet. The apparent total digestibility of Zn and Cu was higher for swine fed hydroxychloride Zn supplemented at 80 mg/kg compared to swine fed the same level of Zn from sulphate sources (p=.039 and p=.049 for Zn and Cu respectively). The carcass yield was higher for swine fed hydroxychloride Zn compared to swine fed sulphate sources, regardless of Zn level used (p<.0001).  

Although swine fed sulphate minerals showed improved performance during the grower period, swine fed hydroxychloride minerals showed improved performance during the finishing period and a greater carcass yield and mineral digestibility compared to swine fed sulphate mineral sources. Average daily gain in the finisher period was 774g for swine receiving hydroxychloride zinc compared to 728g (p =.088) for swine receiving sulphate counterparts. Swine fed Zn and Cu hydroxychloride mineral sources also had a higher carcass yield (p<.0001) than those fed Zn and Cu sulphate mineral sources.

Diets containing lower supplemental levels of Zn decreased the Zn (p<.0001) and Cu (p =.018) excretion by 45.5% and 18.5% respectively (see figure below). The study findings complement previous studies reporting that Zn and Cu excretion could be reduced without negative effects on growth performance, for instance, by 50% by reducing trace mineral supplementation below commercially-used levels.

Remarking on the findings, Trouw Nutrition researcher Sandra van Kuijk says, "These findings build on prior research regarding the beneficial effects of hydroxychloride minerals on animal health, while also offering encouraging insights for animal nutritionists and producers concerned about protecting the environment. Environmentally responsible food production and reducing levels of antimicrobial resistance are significant issues for producers around the globe, and advancements in precision nutrition - such as supplementing with hydroxychloride mineral sources — can support swine producers in achieving their production goals."

The full study results can be found at:


Grower finisher pigs fed hydroxychloride sources of zinc and copper (80 mg/kg vs. 20 mg/kg) excreted less copper compared to their counterparts fed sulphate sources.