All media

Press release - Thursday, December 17, 2015

Dietary zinc supplementation in piglets can prevent claw problems. For sows, (soft) flooring is more important to prevent lameness.

Zinc is good for (finger)nails and this seems to be true for piglets too, according to recent doctoral research by Miriam van Riet. For grown sows, however, adding zinc to their feed had little or no effect, however; in that study, the choice of flooring (bare concrete vs. rubber) appeared to be more important for them.

Claw problems in pigs: the link with zinc

Claw problems in pigs can lead to lameness, a condition that hurts the animal as well as the profitability of the farm. Claw problems can be driven by a number of factors such as flooring and diet. Zinc, an essential micromineral, appears to be important for horn production but the precise mechanism is not clear. Determining zinc deficiency in pigs is also not easy to do, so Miriam van Riet dove deep into the question of how to determine zinc status in pigs and the role of zinc concentrations in claw quality in pigs.

Methods for measuring zinc in the pig

Miriam van Riet first scoured the scientific literature to find all of the various ways to determine zinc deficiency and also to determine how much zinc the animal needs and which types of zinc are best taken up by the pig via diet. van Riet determined that several different methods are possible; some work well but should be chosen with care, as they can be more appropriate for some studies than others. Furthermore, van Riet discovered during a long-term study with 15 sows that various methods work better at various times during the reproductive cycle, which can also influence interpretation of the results.

Zinc in the feed, zinc in the sow?

To determine whether the type of zinc and protein source in feed influences the zinc availability for the animal and what its zinc status would be, a study was set up with 56 sows at the end of gestation. For 20 days they got either organic or inorganic zinc supplementation in a feed with either soybean meal or hydrolyzed feather meal. The type of zinc and protein source had no influence on the amount of zinc in the manure of the pigs.

A feed supplementation test was done with 24 weaned piglets and 131 sows. These groups received either zinc supplementation or not (106 mg total Zn as ZnO/kg in the piglet feed and 50 of 100 mg added Zn/kg for the sows). The sows were also divided between group-housing pens with an exposed concrete floor or pens partially covered with rubber flooring. The piglets had higher zinc levels in blood plasma and showed better claw health, but for sows only rubber flooring had a beneficial effect. This effect of flooring will continue to be studied at ILVO and Ghent University.


Greet Riebbels, Communications at ILVO,, +32 486 26 00 14
Miriam Van Riet, PhD,, +31 64 644 7497
Sam Millet, ILVO promotor,
Geert Janssens, UGent promotor,