Associations between drinking-water nitrate and the productivity and health of farrowing swine

The associations between nitrate contained in drinking water and farrowing swine health and productivity were examined, The study was conducted from November 1989 through February 1991 on 571 randomly selected swine farms (27 207 farrowing swine) in the United States, At the beginning and end of each farm's 3-month monitoring period, the drinking water provided to the fan;owing swine was tested for nitrate. Data on farrowing swine health and productivity were observed and recorded daily by the animal caretaker. Data were analyzed on a farm basis, Nitrate was detected in 53.2% (304/571) of well-water samples, with a median concentration of 2.1 ppm. No association was seen between the nitrate concentration of drinking water and the farm litter size (P=0.94), proportion of the pigs stillborn (P=0.48), or the risk of having an above median percentage of the litter born mummified (OR=1.0; 95% CI 0.99, 1.00). No association was seen between nitrate and the health of farrowing swine as measured by the risk of having an above median percentage of farrowing swine ill (OR = 1.0; 95% Cl 0.99, 1.00) or dead ( OR = 0.99; 95% Cl 0.98, 1.01) due to farrowing problems, other reproductive problems (ill OR = 1.0, 95% CI 1.00, 1.01; dead OR = 1.0, 95% CI 0.98, 1.01), other known health problems (ill OR = 1.0, 95% CI 0.99, 1.00; dead OR = 1.0, 95% CI 0.99, 1.01), or unknown health problems (ill OR = 1.0, 95% CI 0.99, 1.01; dead OR = 1.0, 95% CI 0.99, 1.01). The results of this study indicate that nitrate contained in drinking water, at the concentrations seen during the National Swine Study, is not associated with the farrowing swine health or productivity parameters studied.