Evaluation of adenosine triphosphate testing for on-farm cleanliness monitoring compared to microbiological testing in an empty pig farrowing unit

Association between adenosine triphosphate luminometry of feeding equipment and environmental and health parameters of preweaning calves on dairy farms

The objective of this study was to examine the influence of different environmental factors on ATP luminometry measurements of feeding equipment and to investigate associations with health of preweaning calves and the levels of ATP identified through luminometry. On 50 commercial dairy farms in Quebec, Canada, ATP luminometry measurements (in relative light units, RLU) were obtained using the direct swabbing technique with Hygiena UltraSnap swabs and a liquid rinsing technique with the same swab for automatic milk feeders (AMF), bottles, buckets, esophageal tube feeders (ET), milk replacer, nipples, and water. During this visit, environmental factors (including temperature, air draft, humidity, ammonia, and bacterial count) were collected, and a clinical examination (including respiratory score and fecal score) was performed for all preweaning calves present at the farm. This process was repeated 4 times in a year, leading to collection of luminometer results, environmental parameters, and overall health of calves for each season per farm. Overall, a difference in luminometer results was seen between the different periods sampled for all feeding equipment (except the ET), milk replacer, and water, showing higher RLU values in spring and summer and lower values in autumn and winter. When comparing RLU measurements with environmental factors, only a low to negligible correlation could be found. When feeding equipment was classified as not contaminated or contaminated based on previously described cutoff values, a good agreement within a farm for the different seasons was noticed only for nipples (Gwet's agreement AC1 = 0.64), with a poor to moderate agreement for other feeding equipment. Regarding the different models of nipples, Peach Teat nipples showed higher RLU values compared with Merrick's nipples. An association was seen between the proportion of preweaning calves suffering from diarrhea on the farm and the contamination of AMF based on ATP luminometry (logistic regression estimate = 0.52). For other feeding equipment, milk replacer, and water, no significant associations were found. This study showed that ATP luminometry measurements of feeding equipment from preweaning calves are susceptible to seasonality and type of nipple. Thus, these factors should be taken into consideration when interpreting results. Additionally, an association could be made between diarrhea in preweaning calves and the contamination of AMF based on ATP luminometry, showing the potential clinical importance of this on-farm hygiene assessment tool.

Optimising the hygiene of a liquid feeding system to improve the quality of liquid feed for pigs

Poor feeding system hygiene may contribute to uncontrolled spontaneous fermentation in liquid pig feed and its associated undesirable effects. This study aimed to determine the effects of an intensive sanitisation programme in a grow-finisher liquid feeding system by monitoring microbiological and physico-chemical parameters of liquid feed and microbial colonisation of the feeding system surfaces. The sanitisation programme involved a combination of physical and chemical cleaning between batches of grow-finisher pigs, combined with nightly rinsing of the system with an organic acid blend. Improved hygiene of the internal surfaces of the mixing tank and feed pipeline, particularly until week 5 post-cleaning, was evidenced by reduced counts of lactic acid bacteria, total aerobes, Enterobacteriaceae, yeasts and moulds and decreased adenosine triphosphate concentrations. Enterobacteriaceae and moulds remained undetectable on pipeline surfaces for 10 weeks. Scanning electron microscopy of the feed pipelines confirmed these findings. Conversely, the impact on liquid feed microbiology was minimal and short-lived. However, acetic acid, ethanol and biogenic amine concentrations decreased in the feed post-cleaning and no gross energy losses were observed. Therefore, by controlling surface microbial communities on liquid feeding systems via implementation of the sanitisation programme developed in the current study, on-farm liquid feed quality should be improved.

Hygiene Assessment of Buffalo Milking Parlours in Campania Region, Italy: A Preliminary Study by Using ATP Luminometry and Bacteriological Investigation

Careful cleaning of a milking parlour and its equipment is fundamental to guarantee good raw milk quality and prevent the dissemination of bacteria and improve animal welfare. This study aimed to investigate, using an ATP-bioluminescence assay and bacteriological analysis, the bacterial contamination of milking parlours on milking parlour surfaces of buffalo farms in the Campania Region, evaluating the seasonal dynamics during the year 2022. Eight farms were selected by the Italian ClassyFarm system, which assesses the level of animal welfare and biosecurity according to risk analysis. Before sampling, all dairy farm owners filled out a questionnaire on milking management, animal hygiene, and health. The questionnaires evidenced similar cleaning procedures but an absence of a standardised cleaning protocol among the different farms. ATP bioluminescence results evidenced similar levels of contamination in all the selected buffalo farms, and the season comparison showed no significant differences. A variation in the percentages of bacterial isolates during the different seasons was observed, with a higher prevalence of Enterobacteriaceae (38%) in summer. A small number of samples exhibited an absence of bacterial growth. Identifying bacteria is crucial for understanding the microorganisms present in the milking parlour, yet employing ATP luminometry could offer broad and accurate applications in buffalo milking parlours. In conclusion, the use of ATP bioluminescence for evaluating the hygiene of a buffalo milking parlour could represent a further important advancement in dairy farming technology.

Effect of implementing an effective farrowing accommodation hygiene routine on clinical cases of disease, medication usage, and growth in suckling and weaned pigs

The few studies that have evaluated hygiene routines in farrowing accommodation to date have focused on pathogen elimination from pens, with little attention paid to pig growth and no information provided on pig health or medication usage. This study aimed to determine if implementation of an optimized farrowing accommodation hygiene routine could improve pig health and growth and reduce medication usage pre- and post-weaning (PW). Forty seven sows were blocked on parity, previous litter size and body weight and assigned to two treatments: T1) Basic hygiene: cold water washing only with minimal drying time; T2) Optimized hygiene: use of detergent and a chlorocresol-based disinfectant with a 6-d drying time. Total bacterial counts (TBC), Enterobacteriaceae counts and adenosine triphosphate (ATP) swabs were obtained from different areas within the farrowing pens. Pig growth and medication usage were monitored from birth to slaughter and carcass data were obtained at slaughter. On entry of sows to the farrowing pens, TBC and Enterobacteriaceae counts and ATP concentrations were lower on pen surfaces subjected to the optimized compared to the basic hygiene routine (P < 0.05). Pre-weaning diarrhea prevalence was lower in pigs born into optimal compared to basic hygiene pens (0 vs. 22%; P < 0.001). The number of clinical cases of disease and injections administered to piglets per litter was 75% and 79% less for the optimized compared to the basic hygiene routine, respectively (P < 0.001). This led to reductions of 77% (P < 0.001) and 75% (P < 0.01), respectively in the volume of antibiotics and anti-inflammatories administered per litter in the optimized hygiene group. Pigs from the optimized hygiene treatment were also heavier at weaning (P < 0.01) and their average daily gain (ADG) was higher from day 21 to weaning and days 22 to 49 PW (P < 0.05). However, these growth improvements did not carry through to the finisher period. In conclusion, implementation of an optimized hygiene routine reduced the bacterial load in farrowing pens, leading to a reduction in diarrhea and clinical cases of disease and therefore, medication usage, in suckling pigs. Pig growth was also improved during the suckling and early PW periods. Based on the results, an easily implementable farrowing room hygiene protocol with demonstrable benefits for pig health, growth, and welfare can be provided to farmers.

Evaluation of ATP bioluminescence for rapid determination of cleanliness of livestock trailers after a commercial wash

Pathogens such as porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome (PRRSV), and E. coli are known to spread by contaminated vehicles and equipment. Pork producers have adopted trailer wash policies where each trailer is washed, disinfected, and dried before it can return to a farm. Cleanliness of livestock trailers after washing is determined by visual inspection rather than any objective method. Adenosine triphosphate (ATP) bioluminescence is used in many industries to provide real-time feedback on surface cleanliness through the detection of ATP from organic sources. That same technology may provide trailer wash facilities a way of objectively characterizing a livestock trailer's suitability to return to a farm after washing. Two ATP luminometers (3M Clean-Trace and Neogen AccuPoint) were used to estimate the correlation between ATP bioluminescence readings and aerobic bacterial plate counts (APCs) from sampled surfaces and to determine locations within a livestock trailer that can accurately estimate surface cleanliness. Five locations in livestock trailers were evaluated. Those locations included the nose access door (NAD), back door flush gate, rear side access door (RSAD), belly flush gate (BFG), and belly side access door (BSAD). There was a positive log-log association between the two luminometers (r = 0.59, P < 0.01). Every log unit increase in one unit, resulted in a 0.42 log increase (P < 0.01) in the other unit. ATP can come from bacteria, yeasts, molds, and manure. There was a poor association (r ≥ 0.10, P ≥ 0.02) between APCs and the ATP luminometers. Still, an increase in relative light units (RLUs) resulted in a corresponding increase in colony-forming units. The greatest area of surface contamination measured by APC was the NAD. RLUs were also greater in the NAD compared to the RSAD, the BFG, and the BSAD (P ≤ 0.01). Because APCs and luminometer RLUs provided similar outcomes, statistical process control charts were developed to determine control limits for RLUs. This provides real-time feedback to trailer wash workers in determining cleanliness outcomes for livestock trailers. These data suggest that ATP bioluminescence can be a reliable method to monitor cleaning effectiveness in livestock trailers. Bioluminescence is a monitoring tool that should be used in conjunction with microbial methods to monitor procedures for cleaning and disinfection.

Hygiene management practices and adenosine triphosphate luminometry of feeding equipment in preweaning calves on dairy farms in Quebec, Canada

The objective of this study was to describe the cleaning practices currently used for preweaning calves on dairy farms in Quebec, Canada. In addition, contamination of feeding equipment for preweaning calves was described using ATP (expressed as relative light units, RLU), visual assessment, and bacteriological analysis. A questionnaire was administered on 50 commercial dairy farms in Quebec, Canada, regarding the self-reported cleaning protocol used for feeding equipment of preweaning calves. During the visit, a visual score was given to the feeding equipment available at the farm. Afterward, ATP luminometry measurements were obtained using Hygiene UltraSnap and MicroSnap swabs (Hygiene, Camarillo, CA), and the liquid rinsing technique for buckets, nipples, bottles, esophageal tube feeders (ET), the tube of automatic milk feeders (AMF), water samples, and milk replacer. An additional direct swabbing technique was performed on buckets and nipples. The fluid retrieved from the liquid rinsing technique was also used to determine the total bacterial count (TBC) and total coliform count. Based on the bacteriological analysis, optimal RLU cutoff values to determine contamination were obtained. The median (interquartile range) luminometer measurements using the UltraSnap and direct technique for buckets and nipples were 2,082 (348-7,410) and 3,462 (462-7,518) RLU, respectively; and, using the liquid technique for bottles, ET, AMF, water, and milk replacer were 43 (4-974), 15 (4-121), 301 (137-1,323), 190 (71-358), and 94 (38-218) RLU, respectively. Overall, for all equipment and both techniques used, higher RLU values were seen in UltraSnap samples compared with MicroSnap samples. Additionally, for buckets and nipples, higher RLU values were obtained for the direct swabbing method compared with the liquid sampling method for both swabs used. No differences in the level of contamination were seen between the different feeding equipment used within a farm. Overall, a higher correlation with bacteriological results was noticed for ATP luminometry compared with the visual score, with a high correlation for nipples and bottles using the UltraSnap and liquid technique. Based on the classification of "contaminated" (TBC ≥100,000 cfu/mL) or "not contaminated" (TBC <100,000 cfu/mL), optimal ATP luminometer cutoff values for buckets, nipples, bottles, AMF, water, and milk replacer were 798, 388, 469, 282, 1,432, and 93 RLU, respectively. No clear association was found between ATP measurements and the self-reported cleaning protocol. This study gave new insights into the current cleaning procedures and contamination of feeding equipment for preweaning calves on dairy farms in Quebec. In addition, ATP luminometry cutoff values could help benchmark farms regarding cleaning practices and provide customized advice, improving the overall hygiene management, and thus the health, of preweaning calves on dairy farms.

Erratum to: Evaluation of adenosine triphosphate testing for on-farm cleanliness monitoring compared to microbiological testing in an empty pig farrowing unit

[This corrects the article DOI: 10.5187/jast.2020.62.5.682.].

A Comprehensive Analysis of ATP Tests: Practical Use and Recent Progress in the Total Adenylate Test for the Effective Monitoring of Hygiene

ABSTRACT

Rapid hygiene monitoring tests based on the presence of ATP have been widely used in the food industry to ensure that adequate cleanliness is maintained. In this study, the practical applications and limitations of these tests and recent technological progress for facilitating more accurate control were evaluated. The presence of ATP on a surface indicates improper cleaning and the presence of contaminants, including organic debris and bacteria. Food residues are indicators of insufficient cleaning and are direct hazards because they may provide safe harbors for bacteria, provide sources of nutrients for bacterial growth, interfere with the antimicrobial activity of disinfectants, and support the formation of biofilms. Residues of allergenic foods on a surface may increase the risk of allergen cross-contact. However, ATP tests cannot detect bacteria or allergenic proteins directly. To ensure efficient use of commercially available ATP tests, in-depth knowledge is needed regarding their practical applications, methods for determining pass-fail limits, and differences in performance. Conventional ATP tests have limitations due to possible hydrolysis of ATP to ADP and AMP, which further hinders the identification of food residues. To overcome this problem, a total adenylate test was developed that could detect ATP+ADP+AMP (A3 test). The A3 test is suitable for the detection of adenylates from food residues and useful for verification of hygiene levels. The A3 test in conjunction with other methods, such as microorganism culture and food allergen tests, may be a useful strategy for identifying contamination sources and facilitating effective hygiene management.

HIGHLIGHTS

A risk-oriented evaluation of biofilm and other influencing factors on biological quality of drinking water for dairy cows

Despite the importance of livestock drinking water quality on animal physiology, welfare, and performance, influences such as biofilm formation on trough surfaces on microbial water quality are rarely researched. The objective of this study was to assess the microbial quality of water offered to lactating dairy cows and identify risk factors for poor water quality. We further aimed to determine the impact of biofilm formation on water quality and evaluate rapid test systems to score the hygiene status of dairy troughs on the farm. A total of 105 troughs located on 24 typical Western German dairy farms were sampled. Samples of livestock drinking water and biofilm were analyzed for aerobic total viable count (TVC), coliform count (CC), Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and other bacteria resistant to 3rd generation cephalosporins (CRB). Surface protein- and adenosine triphosphate (ATP)-rapid tests were evaluated to detect biofilm formation. The influence of 22 selected fixed and variable trough characteristics on impaired livestock drinking water quality was evaluated by calculating odds ratios. The average TVC, CC, and E. coli counts were 4.4 ± 0.06 (mean ± SD), 1.7 ± 0.1, and 0.6 ± 0.1 log10 cfu per mL, respectively. CC was detectable in 94.3% of all water samples and E. coli in 48.6%. MRSA was found in pooled livestock drinking water samples of a single farm and CRB on three farms, suggesting that troughs might function as a reservoir of antibiotic-resistant bacteria, thereby contributing to an exchange of antibiotic-resistant bacteria between animals. Risk factors for the impairment of at least one microbial quality criteria (TVC, CC, or E. coli) increased significantly (P < 0.05) when using high-volume troughs, other trough materials than stainless steel, a lower distance to the milking parlor, heavy visible soiling, biofilm formation, and high ambient and high water temperatures. CC (r = 0.46; P < 0.001) and E. coli (r = 0.31; P < 0.01) of water samples correlated with their equivalent in biofilm and with the results of rapid tests on trough surfaces (0.31 > r > 0.19; P < 0.05). Addressing the identified risk factors could be an approach to ensure sufficient biological quality of livestock drinking water.

Interaction between Biofilm Formation, Surface Material and Cleanability Considering Different Materials Used in Pig Facilities—An Overview

Sometimes the contamination in pig facilities can persist even after the washing and disinfection procedure. Some factors could influence this persistence, such as bacteria type, biofilm formation, material type and washing parameters. Therefore, this review summarizes how the type of surface can influence bacteria colonization and how the washing procedure can impact sanitary aspects, considering the different materials used in pig facilities. Studies have shown that biofilm formation on the surface of different materials is a complex system influenced by environmental conditions and the characteristics of each material’s surface and group of bacteria. These parameters, along with the washing parameters, are the main factors having an impact on the removal or persistence of biofilm in pig facilities even after the cleaning and disinfection processes. Some options are available for proper removal of biofilms, such as chemical treatments (i.e., detergent application), the use of hot water (which is indicated for some materials) and a longer washing time.