Clean farm yards and boots reduce biosecurity risks during feed deliveries

Monday, August 5, 2013

A six-week study shows that biosecurity risks occur on only a small proportion of farm visits and that the risk can be further reduced if clean boots and gloves are worn

by CATE DEWEY, KATE BOTTOMS and KAREN RICHARDSON

In January and February, 2013, 40 feed truck drivers from three feed companies participated in a field trial while they delivered feed on 2,202 farm visits. The study investigated potential biosecurity risks associated with the delivery of feed with drivers completing log sheets at all or most farms they visited over a six-week period. Drivers reported information about farm type; type of truck and when the truck was last washed; type of feed being delivered (bulk and/or bags); biosecurity concerns about the laneway and farm yard; the need to enter the barn; and the use of clean boots and/or gloves at each farm.

Drivers were randomly assigned to be in either a control or a treatment group. Drivers in the control group were asked to make no changes as they delivered feed. Drivers in the treatment group were asked to enter the barn only if necessary. They were also provided with either disposable treaded plastic boots or reusable rubber over-boots, and washable cotton gloves. The treatment drivers were asked to wear a clean pair of gloves and boots at each farm whenever possible. One major concern identified by industry personnel was that disposable plastic boots are unsafe to use, especially in winter conditions. Therefore, we provided reusable rubber over-boots as a safer alternative (Figures 1 and 2).  

Two types of rubber boots were provided for the drivers. The boots were washed and dried after being used at each farm. The type in Figure 1 cost $6.50 per pair and $1.75 per pair to wash and dry. The type in Figure 2 cost $15.75 per pair and $1.75 per pair to wash and dry.

More than half of the deliveries were to pig farms (59 per cent), and the rest were to poultry (26 per cent), cattle, sheep or goat farms (14 per cent), or farms with multiple types of animals (one per cent). Most deliveries (65.4 per cent) used a blower truck, while 23 per cent used an auger truck, and 6.1 per cent used a box truck. Other summary information is available in Table 1.

Feed truck drivers take great care to reduce the potential transmission of disease by cleaning the inside of their truck. The steering wheel had been cleaned within the past 24 hours for half of all farm visits, and the floor mats had been cleaned within the past 24 hours for 77 per cent of all farm visits. The entire fleet is typically washed every weekend, and individual trucks were washed throughout the week as required.

Overall, a clean pair of gloves was worn at 30 per cent of farm visits. The rest of the time, drivers wore either gloves that had not been recently washed or no gloves at all (70 per cent). Drivers who were given washable gloves as part of the research used clean gloves more often (66 per cent of the time) than drivers who were not given washable gloves (20 per cent of the time).

Disposable boots were used at seven per cent of farm visits and clean rubber over-boots were used at 21 per cent of farm visits. The rest of the time, drivers wore their own personal boots (72 per cent). Drivers who were given clean rubber over-boots as part of the research used them on 42 per cent of farm visits, and used disposable boots on four per cent of farm visits. These drivers used protective boots more often (on 45 per cent of the farms) than drivers who only had access to disposable boots (10 per cent of the farms).

This six-week pilot study provided a wealth of information about potential biosecurity concerns associated with the delivery of feed. In particular, some of the serious on-farm biosecurity issues discussed by industry personnel – such as manure on the laneway, poor dead stock management, and the driver being asked to enter the barn – happen only at a small proportion of farm visits. This indicates that, although serious biosecurity concerns do exist, the large majority of farms do not pose a threat to the rest of the industry (they do well in these areas). Additionally, drivers belonging to the treatment group wore a clean pair of gloves and/or boots at significantly more farm visits than did drivers belonging to the control group. This initial response is encouraging and serves as a potential intervention that could help reduce the potential biosecurity risk related to the delivery of feed through the use of unclean gloves and personal boots.

We would like to thank all the participants for their input, in particular the feed truck drivers, Ontario Pork and Ontario Agri Business Association for their assistance in securing participants, and the Canadian Swine Health Board for their financial support. BF

Cate Dewey is chair of the Department of Population Medicine, Kate Bottoms is a Research Assistant and Karen Richardson is a technician, Ontario Veterinary College, University of Guelph.