Effect of Feeding a Calcium Chloride Supplement on Sow Stillbirth Rate.

The present study was undertaken to determine the effect of daily calcium chloride (CaCl 2 ) supplementation from day of entry into the farrowing house until day of farrowing (6.4 ± 0.3 d) on stillbirth rates. Landrace × Large White sows (parities 4 to 6; n = 53) were offered 40 g/d CaCl 2 ( n = 28) or served as controls ( n = 25). The morning before their estimated farrowing date, a blood sample was obtained from 25 sows for calcium measurement and a urine sample from 22 sows for pH measurement. The feeding of CaCl 2 decreased urinary pH compared to the control group ( p < 0.001), indicative of an induced metabolic acidosis, but there was no effect of feeding CaCl 2 on serum calcium concentrations or the incidence of stillbirths. Nonetheless, regardless of treatment, sows with higher serum calcium concentrations (>2.5 vs. <2.5 mmol) or lower urine pH (<7.0 vs. >7.0) had fewer stillborn piglets ( p < 0.001 for both). While showing that low serum calcium levels will increase stillbirth rates, our data indicate that the administration of 40 g/d CaCl 2 for 6 d prior to farrowing was not sufficient to increase serum calcium or decrease stillbirth incidence.