Interpretive Summary: Effects of supplementing late-gestation sow diets with zinc on preweaning mortality of pigs under commercial rearing conditions
By: Anne Walace
The leap from gestation to lactation places a great deal of physiological stress on sows, which may impact piglet viability and survivability. Pre-weaning piglet mortality is problematic on commercial swine farms, causing substantial production losses and animal welfare concerns. Various factors contribute to pre-weaning mortality, occurring within 48 hours of farrowing, and as many as 1 in 4 piglets may be lost. Low piglet birth weight (less than 1 kg) is one such cause.
The authors of this April 2020 Translational Animal Science study evaluated zinc supplementation as a potential way to improve piglet survivability. They hypothesized that by supplementing gestating sows with zinc, the pre-weaning survival of piglets would improve due to increased birth weights.
Sows were fed a corn-soybean meal diet supplemented with three concentrations of dietary zinc, starting from day 85 of gestation, as follows: 1) control zinc diet = CON (125 ppm), 2) intermediate zinc diet = INT (365 ppm), and 3) high zinc diet = HI (595 ppm). Piglet birth weights and mortality rates were subsequently documented. Sows fed INT had higher piglet birth weights than the CON sows, and similar birth weights to HI sows. The incidence of low birth weights was also lowest in the INT sows. Furthermore, among low birth weight piglets, mortality rates were lowest in INT and HI sows, when compared to CON sows.
The findings of this study suggest that zinc supplementation of gestating sows starting at 365 ppm may improve pre-weaning piglet mortality by increasing piglet birth weight and decreasing the incidence of low birth weight. More comprehensive studies looking at zinc combined with other vitamins or minerals may be justified to better understand the impacts of sow nutrition on preweaning mortality in piglets.