Abstract: An innovative and well-adapted statistical method, called multiblock redundancy analysis, is proposed for a complex health-event analysis to account for the thematic block organization of variables. The outcome block contained the condemnation rates of 404 broiler chicken flocks, distinguishing infectious and traumatic condemnation categories. Explanatory variables were organized in blocks related to the different production stages (farm structure and routine husbandry practices; on-farm flock history and characteristics; catching, transport and lairage conditions; slaughterhouse and inspection features). The aim was to determine risk factors for both condemnation categories, and the relative impact of the different production stages on the whole condemnation rate. Results showed that significant factors were either specific to one condemnation category or related to both categories, and each of the explanatory blocks was involved in the explanation of infectious and traumatic condemnation rates. On-farm flock information explained 40% of the overall condemnation process whereas the other explanatory blocks had similar relative impacts.
Abstract: A field study was conducted to estimate the sanitary condemnation proportion in male turkey broiler flocks, to describe the reasons for condemnation and the related macroscopic lesions, and to investigate whether primary production information would predict the risk of condemnation. Male turkey standard broiler flocks (117) were randomly selected in the 13 slaughterhouses located in Western France, from February to July 2006. The flocks were monitored from their arrival at the slaughterhouse until the results of the post mortem sanitary inspection. Information about rearing conditions, health history, catching and loading conditions, transportation to the slaughterhouse and slaughtering was also collected. Sampling design was considered in the calculations and the condemnation proportion was modelled using a negative binomial regression, accounting for clustering within slaughterhouse. The within-flock weighted average condemnation proportion was 1.8% (95% confidence interval, 1.3-2.3%). Emaciation, arthritis-polyarthritis and congestion were the main reported official reasons for condemnation, representing 76% of the condemned carcases. Three variables were significantly associated with increased risk of condemnation: observed locomotor disorders on the farm, high cumulative mortality 2 weeks before slaughter, and clinical signs observed by the Veterinary Services during the ante mortem inspection at the slaughterhouse. The final model explained 35% of the total variation in condemnation risk. Half of this explained variation could be attributed to locomotor disorders observed during rearing. The sensitivity and specificity of the model to predict a high flock condemnation risk were 80% and 74%, respectively, when using an optimum threshold of 0.95% to define high risk. The results of this study suggested that the variables found to be associated with condemnation proportion were markers of increased risk and could be used as indicators. These risk indicators can easily be retrieved from the pre-existing regulatory document transmitted before flock arrival at the slaughterhouse and could be used to screen flocks before slaughter, according to their expected risk of condemnation.
Abstract: The feasibility of using risk markers to screen broiler chicken flocks and anticipate their risk of condemnation at meat inspection was examined in 404 randomly selected flocks in 15 French slaughterhouses in 2005. Condemnation rate and information about rearing conditions, health history, catching and loading, transport and slaughtering were collected. The Poisson regression model of the condemnation rate consisted of six simple and biologically relevant predictors: production type, frequency of farmer's visits during the starting period, health disorders during rearing, on-farm mortality, mortality during transport, and slaughter-line speed. Although accurate prediction of the condemnation rate for a given flock was not feasible, flocks with low or high risk of condemnation could be distinguished. These findings could be useful at various stages of chicken production, to monitor and improve farm husbandry practices, minimize the impact of transport conditions, and optimize meat inspection procedures.
Abstract: 1. This slaughterhouse-based study was to evaluate correlations between cutaneous lesions which are linked to animal welfare. The relationships between these lesions and various rearing factors were investigated. 2. The percentage of lesions in each flock was determined by observation at the slaughterhouse. Fifty-five flocks slaughtered between May 2005 and May 2006 in 8 slaughterhouses were investigated. 3. Data relating to farm management and housing factors during the rearing period were collected retrospectively from 36 of the 55 flocks scored for lesions. 4. A negative correlation was observed between (i) presence of breast blisters and deep hock burns, (ii) presence of breast blisters and deep footpad dermatitis, and (iii) presence of breast burns and scratches. 5. We proposed an assessment of broiler chicken welfare at the slaughterhouse on the basis of several criteria: (i) footpad dermatitis, hock burns and breast burns, (ii) scratches, and (iii) breast blisters. 6. The presence of contact dermatitis was related to litter quality and several management factors. Only scratches and breast blisters were related to high stocking density. The type of lesion was related to genotype. Genotype A (fast-growing) had fewer breast blisters but deeper footpad lesions than B (slower-growing).
Abstract: A total of 404 broiler chicken flocks processed in 15 slaughterhouses in western France were studied to estimate the condemnation prevalence and describe the official reasons for condemnation and the main macroscopic lesions observed in a sample of the condemned carcases. The condemnation rate was 87 per 10,000 birds slaughtered (95 per cent confidence interval 79 to 95 per 10,000) but differed significantly according to the type of poultry produced (standard, light, heavy or certified). The main reasons for condemnation were emaciation and congestion, with rates of 30 and 22 per 10,000 birds slaughtered, respectively. Congestion was significantly associated with arthritis and ascites, whereas infected skin lesions were associated with bruises and abnormalities of colour, odour or conformation.
Abstract: Current monitoring of exceptional mortality events of oysters in France consists in passive surveillance, leading to delayed investigation of causation by scientists and management by policy makers. Early detection of clusters of mortality events in time and space would increase possibilities for their investigation and management.
A space-time cluster analysis of existing mortality notifications in Pacific oysters was conducted in France, Charente sluices, from 2008 to 2010. As an example of potential demographic confounder of clustering, the analyses were adjusted on oyster age. Several clusters were identified in space and time each studied year. Patterns of mortality notifications were consistent with the introduction and spread of a contagious disease in 2008, which may have become endemic since 2009. Adjustment on oyster age did not change patterns of clusters, suggesting that other variables should be considered in risk factor analyses for mass mortality, either at animal or at environmental level.
The routine space-time cluster analysis would be a useful tool to early detect unusual mortality events, with both objectives to improve the epidemiological understanding of the event and to implement timely and efficient control measures. The evolution of the French surveillance strategy from a passive to such a cluster-based surveillance system may be conceivable, if full collaboration of all stakeholders could be achieved.
