Table 1 General information of case farms A and B

Type of farm

Farrowing unit

Weaning unit

Herd size and management

1200 sows, three-weeks batches

1800 pigs/batch, two batches present in two different sectors of the barn, the first 6 weeks older than the second

Drinking water

Ground water

Ground water

Cleaning and disinfection

Dirt was manually removed; crates were then soaked with a commercial product, removed using water under high pressure (220 bar) and a disinfection product contained chloride was applied. Crates were left empty for 2–3 days.

Cold water was used for cleaning the pens. Pens were first soaked with a commercial product. Dirt was removed by using water under high pressure (220 bar). The applied disinfection product contained chloride. The stand-empty period was 1 week.

Stressful operations

Cross-fostering of piglets from one sow to another; surgical castration and iron injection (day 3 of life); vaccination toward M. hyopneumoniae and porcine circovirus type 2, skin tattoo for Parma ham regulation (day 21 of life).

Moving little piglets from a pen to another for size balancing intra-batches; vaccination towards Aujeszky’s disease (day 70 of life).

Rodent control program

A professional company was responsible for the rodent control. No excessive trails such as feces, damage to insulation and corpses of rat and mice were observed.

A professional company was responsible for the rodent control. Trails, such as damage to insulation and presence of rat feces were visible.