Date Full Report Received


Date Abstract Report Received



Primary Investigator:
Co-Investigators: Julia Holen, Jae Cheol Jang, Mark Schwartz, Jerry Shurson, Lee J. Johnston

Industry-wide, pre-weaning mortality has increased from about 17.7% in 2012 to 22.3% in 2017, especially among pigs < 1 kg in birthweight. Supplementing zinc to gilts from day 85 of gestation until farrowing increased survival of pigs by decreasing stillbirth and pre-weaning mortality. However, there are multiple reasons why this intervention needs testing; the data were collected in a small research farm, there are no data on the impact of zinc supplementation on survival of pigs born from sows across different parities, at current industry number of pigs born, or at commercial management practices such as cross-fostering. Therefore, our project studied the impact of additional zinc in late gestation on pre-weaning mortality at a commercial sow farm following the mentioned criteria. At the end of gestation (day 75), sows (n = 339) were fed diets supplemented with zinc at current farm practice (275 mg/d) and two additional levels (577 or 1,154 mg/d). We observed a decrease in pre-weaning mortality of piglets from sows supplemented with zinc intermediate (13.2%) and high levels (12.2%) when compared with the current practice (15.0%). Among piglets of < 1 kg birthweight, pre-weaning mortality was least in piglets from dams supplemented zinc at high zinc (28.1%), followed by intermediate (36.4%), and highest in the current practice (38.3%). The decrease in pre-weaning mortality of zinc supplemented dams was not affected by the incidence of < 1 kg pigs. Likewise, surviving pigs from zinc supplemented dams had market weights and carcass composition that were not different from other pigs. These observations suggest that piglets saved from the intervention are likely to have similar productivity. A partial budget calculation suggests a decrease in market pig cost by $ 1.5 when sows are supplemented with zinc that cost $ 0.3. In conclusion, transition sow diets supplemented with zinc during the last term of gestation increase survival and productivity of pigs.

Key Findings:
1. Feeding additional zinc (275 mg/d vs. 577 or 1,154 mg/d) in late gestation (day 75) decreased pre-weaning mortality (15.0 vs. 13.2 and 12.2%; respectively).
2. The intervention was effective primarily among low birthweight pigs (< 1 kg) and resulted in about 0.3 additional pigs saved.
3. Pigs from sows fed additional zinc had postweaning growth performance and carcass characteristics that were not difference from other pigs.
4. Feeding additional zinc did not change birthweight or litter weight distribution.