**1. Introduction**

Transportation coops have been shown to be a vector for cross-contamination during the 3–12 h transportation and holding period that occurs before birds are processed [1]. These coops contain organic matter and microorganisms left by previously transported flocks [2]. Salmonella and *Campylobacter* levels can increase by 20 to 40% during loading, transportation, and holding before being processed [3–5]. Transportation is a known stress factor in poultry production and is why studies show increasing levels of microorganisms during this event [6]. Poultry transportation coops are not required to be cleaned and disinfected prior to reuse, which may lead to cross-contamination between broiler flocks [5,7]. Broilers determined to be negative for *Campylobacter* become positive post-transportation in coops previously used for transport of *Campylobacter* positive flocks [7]. Research has been conducted to evaluate reductions in bacteria present on transportation coops by washing and allowing an extended drying time. These methods were found to be successful, but were considered impractical for the industry since this would require more coops and a large amount of space for drying [3].

*Campylobacter* and Salmonella are a concern within the industry because of their prevalence in poultry products [8]. Disinfectants such as peroxyacetic acid (PAA) are currently used in chillers at poultry processing plants because of its ability to reduce microorganisms, such as *Campylobacter* and Salmonella [9]. Guidelines to control and prevent these two microorganisms have been written and are in place for the poultry industry [10]. Researchers have collected carcass samples within poultry processing plants to determine where the highest loads of *Campylobacter* were found [11]. Mechanical feather removal within the processing plant is one area where bacterial load has been shown to increase, picker fingers cross-contaminate feather follicles with high levels of organic matter containing microorganisms which may further contaminate carcasses [12]. Lowering the number of microorganisms and organic matter entering the plant from transportation coops should result in less organic matter on carcasses and possibility reducing cross-contamination.

The poultry industry may use firefighting foam to depopulate birds during a reportable disease outbreak. The emergency technique has been conditionally approved by the American Veterinary Medical Association and the USDA-Animal Plant Health Inspection Service [13]. Foam is a quick alternative method to depopulate broilers that can be less labor intensive than gas asphyxiation [14]. Using a compressed air foam system (CAFS) may also be an efficient way to disinfect and sanitize poultry transportation coops. Disinfecting treatments using CAFS have been shown to reduce aerobic bacteria on layer cages and broiler transportation coops [15,16]. The food industry uses foaming disinfectants and cleaners to reduce microbial surface contamination, suggesting that a scalable approach using CAFS has potential.

In this study, we evaluated peracetic acid and a foaming cleaner that is commonly used by the poultry industry. Peracetic acid is a mixture of hydrogen peroxide and acetic acid. It is a robust disinfectant that can tolerate high organic loads ye<sup>t</sup> decomposes into relatively safe by-products. It denatures proteins and increases cell wall permeability. The foaming cleaner was a proprietary formulation consisting of 5–10% potassium hydroxide, 1–3% sodium hypochlorite and a foaming agent. Alkaline ingredients are used to saponify lipids and help with the removal of organic matter. While the foaming cleaner was not labeled as a disinfectant, the strong base and sodium hypochlorite were expected to have some antimicrobial activity. Chlorine products are inexpensive and effective disinfectants that can kill or damage microbes due to oxidation of proteins and disruption of cell membranes. Unfortunately, they are also quickly depleted in the presence of organic matter [17].

The objective of the current study was to evaluate the disinfection of poultry transportation coops using a foam cleaner (FC), PAA + FA, or PAA + FA with a high-pressure water rinse (HPWR) prior to or following the foam application on aerobic bacteria and *Salmonella* recovery. A field study was conducted at a commercial poultry processing facility. This trial evaluated PAA + FA alone and with a HPWR prior to the foam application to evaluate aerobic bacteria present on poultry transportation coops. We hypothesized that the application of disinfectants or cleaners with foam using the CAFS would significantly reduce *Salmonella* and aerobic bacteria on broiler transport coops.
