Clinical study of mastitis-metritis-agalactia in sows in Illinois

Mastitis-metritis-agalactia (MMA) occurred in 6.9% of 16,405 farrowings recorded over 1 year (1981) in 31 Illinois swine herds. Prevalence of MMA among herds ranged from 1.1% to 37.2% and was not correlated to herd size. There was a significant positive correlation between the prevalence of MMA and the housing system wherein sows were moved from pasture gestation to crates immediately before farrowing. A significant seasonal peak of MMA was found for the third quarter of the year (10.3%). Mean prevalence of MMA was 13% in pluriparous sows and 4.2% in primiparous sows. The difference was not significant. Sows with MMA gave birth to more live pigs per litter compared with healthy sows (+0.7 pigs per litter). The number of stillbirths and pigs found dead after birth also was higher in sows with MMA (+4.6%). Total pig mortality until 1 week of age was 56% in litters of pluriparous sows with MMA and 17% in litters of healthy pluriparous sows and, respectively, 41% and 15% in litters of primiparous sows. The mean number of pigs per litter surviving at 1 week of age was 5.6 in pluriparous sows with MMA and 9.3 in healthy sows and, respectively, 6.2 and 8.3 in primiparous sows. For all herds investigated, mean litter size at birth (including stillbirths) was 11.0. Total pigs mortality until 1 week of age was 31%. Pig losses attributable to MMA, at 6.9% prevalence of the disease, were 4% of all pigs born and 12.9% of the pig mortality until 1 week of age.