Reliability of an ordinal rating system for assessing the amount of mud and feces (tag) on cattle hides at slaughter

Intraobserver and interobserver reliability of mud scoring systems for use in cattle at slaughter

At slaughter plants, live cattle are often scored for mud coverage as mud on hides can impact food safety and drives decisions regarding interventions during processing. Currently, there is no standardized method utilized to assess mud coverage. The aim of this study was to determine the intraobserver and interobserver reliability of 3, 4, and 5 point mud scoring systems. Beef cattle (n = 110) were videotaped during movement to holding pens upon arrival at a commercial slaughter facility. Five scorers were assigned to a 3, 4, or 5 point scoring system (n = 15), reviewed the video and assigned the cattle a mud score. A multi-rater weighted kappa analysis was used to determine intraobserver and interobserver reliability for each system. Although all scorers in the 3 point analysis and one scorer each for the 4 and 5 point analysis demonstrated moderate intraobserver reliability, all interobserver reliability kappas were poor (kappa ≤0.12). Further exploration to develop a suitable system that is repeatable is recommended.

Assessment of Small Ruminant Welfare in Ethiopia - An Abattoir-Based Study

This paper presents the results of a cross-sectional study assessing the welfare of sheep and goats in a large abattoir in central Ethiopia, using qualitative and quantitative approaches. A total of 384 nonhuman animals (192 sheep and 192 goats) underwent clinical examination and behavioral observation in 2014. The study also included behavioral observation of 57 animal handlers, and a qualitative assessment of animal welfare conditions at the abattoir. Clinical examination revealed dirty wool/hair (54.9%), poor body condition (15.8%), and respiratory disorders (14.0%). The most commonly observed behaviors were refusing to move (17.1%), panting (15.8%) and reversing (10.4%). Significantly higher proportion of sheep exhibited resistance behaviors such as refusing to move (21.4% of sheep and 13.0% of goats; p < 0.030) and resistance to being pulled (12.5% of sheep and 6.3% of goats; p < 0.0036). Handlers frequently beat (87.7%), pushed (57.9%) and pulled (49.1%) the animals. Poor handling of animals was very common and could result in animal distress and falls. In collaboration with the abattoir workers, the authors developed simple good practice to improve welfare and reduce losses from poor welfare.

An evaluation of selected methods for the decontamination of cattle hides prior to skinning

The effectiveness of different decontamination treatments in reducing microbial loads on cattle hides was assessed. The 10-s hide treatments were conducted using a wet-and-dry vacuum cleaner filled with one of the liquids (heated to 50 °C) indicated below, followed or not by 10-min drying in the air. Also, the hide was clipped, followed or not by 10-s singeing using a hand-held blowtorch. Before and after each decontamination treatment, the hide was sampled (100 cm(2) areas) by a sponge-swabbing method to compare the total viable counts of bacteria (TVC). The largest bacterial reduction (P<0.001; 2.31log(10) cfu/cm(2)) was achieved by singeing of previously clipped hide. Treatment of hide with a food industry sanitizer solution (10% Betane Plus) resulted in significant reductions of 1.80 (P<0.001) and 1.98log(10) cfu/cm(2) (P<0.001) without and with subsequent drying, respectively. Treatment of hide with a food industry disinfectant (P3-Topactive DES) significantly reduced TVC by 0.97 (P<0.001) and 1.18log(10) cfu/cm(2) (P<0.001) without and with subsequent drying, respectively. Treatments of hide with water alone or with a food-safe detergent solution (Formula 963B), or hide clipping alone, did not produce significant decontamination effects. Since hide contamination is associated with microbial contamination of the carcasses, the results indicate that post-killing/pre-skinning hide decontamination (used alone, or in combination with carcass decontamination) has a potential to improve microbial meat safety. Nevertheless, further research is required to optimise the efficacy of these treatments in the reduction of specific pathogens under commercial conditions.

Conditions in lairages at abattoirs for ruminants in southwest England and in vitro survival of Escherichia coli O157, Salmonella Kedougou, and Campylobacter jejuni on lairage-related substrates

Information on lairages (regarding design, construction materials, and use of bedding and cleaning regimes) was collected for 21 commercial cattle and/or sheep abattoirs in southwest England. Overall, roughened or grooved concrete was the most common lairage flooring material. Straw bedding was used in the majority of lairages and was changed between animal batches, daily, weekly, and monthly in roughly 5, 60, 15, and 10%, respectively, of the surveyed lairages. Lairages were commonly washed with cold water with no detergents and/or disinfectants, and only about half the lairages were washed daily. Also, a three-pathogen cocktail inoculum comprising Escherichia coli O157 (NCTC 12900), Salmonella Kedougou (VLA S488/01), and Campylobacter jejuni (VLA C4) (at 8, 8, and 7 log CFU/ml or 8, 8, and 7 log CFU/g, respectively) was suspended in either broth (for nonfecal contamination) or bovine feces (for fecal contamination). Samples of the four most common substrates present in lairages (concrete, straw, metal, and hide) were contaminated in vitro with either fecal or nonfecal inocula and subsequently held in the laboratory at 10 or 25 degrees C for 1 week. Bacterial counts for these samples were monitored daily and used to assess the number of days required for a 90% reduction of each pathogen population. In most cases, pathogens survived for >1 week, with survival rates being higher for straw or hide than for concrete or metal and higher for fecal contamination than for nonfecal contamination. Overall, if survival rates for the three pathogens under practical lairage conditions were similar to the in vitro survival rates found in this study, contamination of lairages with pathogens could be carried over from one batch of animals to another and/or from one day to the next.

Aerobiology of a high-line speed cattle abattoir

The operation of the high-line speed cattle abattoir studied follows a plant-created hazard analysis and critical control point (HACCP) plan that is recognized by the Canadian Food Inspection Agency. Measurement of bioaerosols is not a part of this plan. In this study CFUs in air of selected abattoir processes were enumerated after impinging air onto tryptic soy agar plates with a slit air sampler for 10 to 20 min. The total viable count (TVC) per liter of air was calculated for each sample following incubation at 30 degrees C for 24 h. Monthly samples were collected on the hide removal floor and the carcass dressing floor from March 1998 to April 1999. Mud tag, dirt, and wetness of incoming hides were scored subjectively on the hide removal floor. The other processes were sampled in 3 separate months. The TVC at two locations on the hide removal floor (center of hide removal floor [CHF] and top of hide puller [THP]) had a strong association to each other (r = 0.84; P < 0.001). The mean TVC at the CHF and THP was 10.0 and 11.5, respectively, and the TVC for individual samples ranged from 2 to 42 at these locations. The TVC means for all the other processes ranged from 0.01 to 0.7. Tag and TVC on the hide removal floor had a different seasonal distribution with TVC being highest in the warm months (April to October 1998) and lowest for November to April 1999. No significant relations between TVC and the dirt and wetness variables were evident for the CHF and THP locations on the hide removal floor. It was concluded that the control of aerosols in the hide removal floor should be treated as a critical control point in the HACCP plan.

Pre-slaughter control of Escherichia coli O157 in beef cattle: a simulation study

A stochastic simulation model was used to assess the benefit of measures implemented in the pre-slaughter period that are aimed at reducing the contamination of beef carcasses with Shiga-like-toxin-producing Escherichia coli O157. The scenario studied was based on an abattoir processing approximately 1000 head of lot-fed cattle per day. Input assumptions were described using probability distributions to reflect uncertainty in their true values. Control measures that were assessed were based on either a reduction in herd prevalence of infection, reduction in opportunity for cross-contamination in the processing plant by re-ordering of the slaughter queue, reduction of concentration of E. coli O157 in fresh faeces, or a reduction in the amount of faeces, mud and bedding ('tag') transferred from the hide to the carcass. Some control measures evaluated were hypothetical in nature and were included to assist with the planning of research priorities. Simulations suggested that the greatest potential impact is associated with vaccination and with an agent that reduces shedding E. coli O157 in faeces. Knowledge of herd-test results obtained by testing a sample of animals from the herd provides only a minor advantage in control programmes, although application of a rapid test to all animals in all lots might be of some benefit. Under most scenarios, there is ample opportunity for cross-contamination to occur within the slaughter plant as a result of early entry of cattle contaminated with E. coli O157. An industry-wide reduction in the amount of tag attached to hides and addition of a source of cattle having a prolonged average fasting time were not predicted to have a large impact on mean amount of carcass contamination with E. coli O157.

A simulation model for studying the role of pre-slaughter factors on the exposure of beef carcasses to human microbial hazards

A Monte Carlo simulation model was constructed for assessing the quantity of microbial hazards deposited on cattle carcasses under different pre-slaughter management regimens. The model permits comparison of industry-wide and abattoir-based mitigation strategies and is suitable for studying pathogens such as Escherichia coli O157:H7 and Salmonella spp. Simulations are based on a hierarchical model structure that mimics important aspects of the cattle population prior to slaughter. Stochastic inputs were included so that uncertainty about important input assumptions (such as prevalence of a human pathogen in the live cattle-population) would be reflected in model output. Control options were built into the model to assess the benefit of having prior knowledge of animal or herd-of-origin pathogen status (obtained from the use of a diagnostic test). Similarly, a facility was included for assessing the benefit of re-ordering the slaughter sequence based on the extent of external faecal contamination. Model outputs were designed to evaluate the performance of an abattoir in a 1-day period and included outcomes such as the proportion of carcasses contaminated with a pathogen, the daily mean and selected percentiles of pathogen counts per carcass, and the position of the first infected animal in the slaughter run. A measure of the time rate of introduction of pathogen into the abattoir was provided by assessing the median, 5th percentile, and 95th percentile cumulative pathogen counts at 10 equidistant points within the slaughter run. Outputs can be graphically displayed as frequency distributions, probability densities, cumulative distributions or x-y plots. The model shows promise as an inexpensive method for evaluating pathogen control strategies such as those forming part of a Hazard Analysis and Critical Control Point (HACCP) system.