Introduction
Environmental contamination is a major source of infection for farrowing sows and piglets. Improper cleaning and disinfection allows bacteria protected in dried organic matter such as feces, dust, dirt, feed, and blood to persist. The materials used for surfaces of farrowing crate floors include concrete, triangular bar (tri-bar), and plastic coated expanded wire. Each surface varies in its ability to collect dust and dirt, and the ease with which they can be cleaned.
In this experiment the efficacy of PVPI to disinfect previously cleaned farrowing crate floors, was compared to a cresylic acid disinfectant (185 Premise Cleaner™ BioSentry, Inc., Stone Mountain, GA) commonly used to disinfect farrowing houses. The use of a combination ionic and non-ionic surfactant (Sunlight®, Lever Brothers Co., New York, NY) was also evaluated as an aid in decreasing bacterial populations on the floors of farrowing crates.
Materials and Methods
The study was conducted in four farrowing rooms at the North Carolina State University Swine Educational Unit II. Each room contained twelve crates with floors of slatted concrete underneath the sow, plastic coated expanded metal beside the sow in the creep, and tri-bar behind the sow. Four treatments were applied using an incomplete block split-plot design (Table 1).
Treatment |
Booster1 |
Power wash2 |
Disinfectant3 |
1 |
Water |
Water |
PVPI |
2 |
Water |
Water |
Cresylic Acid |
3 |
Water |
Surfactant |
PVPI |
4 |
Water |
Surfactant |
Cresylic Acid |
|
1 To remove gross contamination, the floors were hosed down by a low
pressure booster pump using only water and allowed to dry for 20 min. 2 The floors were power washed with or without a surfactant (Sunlight™,Lever Brothers Co., New York, NY) using a Karcher™ Power washer (West Patterson, NJ) at 2000 psi and allowed to dry for 20 min. 3 Immediately after power washing, either PVPI (Novel Pharmaceutical, Hamlet, NC) or 185 Premise Cleaner™ (BioSentry, Inc., Stone Mountain, GA) was diluted according to the label and sprayed onto the floors. Floors were allowed to dry for 10 min prior to sampling. | |||
Two treatments were blocked per farrowing room. To minimize cross contamination, 8 crates separated the treatments. Each treatment was replicated three times. One treatment was applied to two adjoining crate floors in the front of the room and the other was applied to two adjoining crates in the back of the room. A 0.094 m2 sampling area was delineated using a portable frame. Two sampling areas on each type of floor (concrete, plastic coated expanded metal, and tri-bar) were sampled using a sample sponge (MicrospongeTM, Micronex, Inc.). A total of six sites were swabbed per crate. Samples were collected after low pressure washing (20 min), power washing (20 min), and disinfecting (10 min).
Mean aerobic bacterial populations were calculated for each replicate on each floor type and each crate in each treatment.
Results
More bacteria were removed from the concrete floor than from the plastic coated expanded floor after cleaning and disinfection. No interactions (P>.05) were found between use of a surfactant and either PVPI or cresylic acid, floor type and surfactant, or floor type and disinfectant. Initial contamination on the concrete floors before power washing and disinfecting was consistently higher than on the other two floors (Figure 1). However, by the end of the cleaning cycle, mean log bacterial counts were similar on all three floors, regardless of treatment (Figure 1).
