Health scores for farmed animals: Screening pig health with register data from public and private databases

Value of simplified lung lesions scoring systems to inform future codes for routine meat inspection in pigs

BACKGROUND

Across the European Union (EU), efforts are being made to achieve modernisation and harmonisation of meat inspection (MI) code systems. Lung lesions were prioritised as important animal based measures at slaughter, but existing standardized protocols are difficult to implement for routine MI. This study aimed to compare the informative value and feasibility of simplified lung lesion scoring systems to inform future codes for routine post mortem MI.

RESULTS

Data on lung lesions in finisher pigs were collected at slaughter targeting 83 Irish pig farms, with 201 batches assessed, comprising 31,655 pairs of lungs. Lungs were scored for cranioventral pulmonary consolidations (CVPC) and pleurisy lesions using detailed scoring systems, which were considered the gold standard. Using the data collected, scenarios for possible simplified scoring systems to record CVPC (n = 4) and pleurisy (n = 4) lesions were defined. The measurable outcomes were the prevalence and (if possible) severity scoring at batch level for CVPC and pleurisy. An arbitrary threshold was set to the upper quartile (i.e., the top 25% of batches with high prevalence/severity of CVPC or pleurisy, n = 50). Each pair of measurable outcomes was compared by calculating Spearman rank correlations and assessing if batches above the threshold for one measurable outcome were also above it for their pairwise comparison. All scenarios showed perfect agreement (k = 1) when compared among themselves and the gold standard for the prevalence of CVPC. The agreement among severity outcomes and the gold standard showed moderate to perfect agreement (k = [0.66, 1]). The changes in ranking were negligible for all measurable outcomes of pleurisy for scenarios 1, 2 and 3 when compared with the gold standard (rs ≥ 0.98), but these changes amounted to 50% for scenario 4.

CONCLUSIONS

The best simplified CVPC scoring system is to simply count the number of lung lobes affected excluding the intermediate lobe, which provides the best trade-off between value of information and feasibility, by incorporating information on CVPC prevalence and severity. While for pleurisy evaluation, scenario 3 is recommended. This simplified scoring system provides information on the prevalence of cranial and moderate and severe dorsocaudal pleurisy. Further validation of the scoring systems at slaughter and by private veterinarians and farmers is needed.

Health Monitoring of Fattening Pigs - Use of Production Data, Farm Characteristics and On-Farm Examination

Background

The use of processed secondary data for health monitoring of fattening pigs has been established in various areas, such as the use of antibiotics or in the context of meat inspection. Standardized scores were calculated based on several sources of production data and can be used to describe animal health in a large collective of pig units. In the present study, the extent to which these scores are related to different farm characteristics and management decisions were investigated. In addition, slaughter scores were compared with the results of a veterinary examination on the farms.

Results

The comparison of the results of the uni- and multifactorial analyses revealed that almost all of the examined factors play a role in at least one of the scores when considered individually. However, when various significant influencing factors were taken into account at any one time, most of the variables lost their statistical significance due to confounding effects. In particular, production data such as production costs or daily feed intake remained in the final models of the scores on mortality, average daily gain and external lesions. Regarding the second part of the investigation, a basic technical correlation between the slaughter scores and the on-farm indicators could be established via principal component analysis. The modelling of the slaughter scores by the on-farm indicators showed that the score on external lesions could be represented by equivalent variables recorded on the farm (e.g., lesions caused by tail or ear biting).

Conclusions

It has been demonstrated that the examined health scores are influenced by various farm and management characteristics. However, when several factors are taken into account, confounding occurs in some cases, which must be considered by consultants. Additionally, it was shown that on-farm examination content is related to the scores based on equivalent findings from slaughter pigs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40813-021-00225-y.

Health monitoring of finishing pigs by secondary data use - a longitudinal analysis

Background

In Germany, animal welfare has become an increasingly important issue. Since 2006, German legislation demands self-monitoring of animal welfare by farmers, but there is a lack of prescribed indicators for governmental monitoring. Since recording of the health status through examinations on individual farms requires many resources, secondary data use is obvious. Therefore, this study deals with the overall evaluation and utilization of existing production data from the German pork production. Performance data and information on antibiotic usage and meat inspection were used for a benchmarking system of animal health in finishing pigs.

Results

Seven health scores and one total score were evaluated for 184 finishing pig herds on semi-annual basis between July 2017 and June 2019, based on the health indicators mortality, average daily gain, feed conversion ratio, treatment frequency, respiratory lesions, exterior lesions and animal management. In preparation, the selected health indicators were brought to the same scale and skewed data were transformed to build scores (MOR, ADG, FCR, TF, RESP, EXT and MANG). A differentiated analysis was carried out for three classes of initial body weight regarding to farmers’ fattening management strategies.

Conclusions

The present study shows that existing production data of German finishing pigs are usable for welfare monitoring. However, preparatory editing steps are crucial. The total score can only be an estimate of health status because partly bad or good performance could be disguised. It has also been demonstrated, that relative benchmarking is suitable for depicting temporary fluctuations in the investigated collective.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40813-021-00197-z.