Simplifying the Welfare Quality® assessment protocol for broiler chicken welfare

Abstract

Welfare Quality ® (WQ) assessment protocols place the emphasis on animal-based measures as an indicator for animal welfare. Stakeholders, however, emphasize that a reduction in the time taken to complete the protocol is essential to improve practical applicability. We studied the potential for reduction in time to complete the WQ broiler assessment protocol and present some modifications to the protocol correcting a few errors in the original calculations. Data was used from 180 flocks assessed on-farm and 150 flocks assessed at the slaughter plant. Correlations between variables were calculated, and where correlation was moderate, meaningful and promising (in terms of time reduction), simplification was considered using one variable predicted from another variable. Correlation analysis revealed a promising correlation between severe hock burn and gait scores on-farm. Therefore, prediction of gait scores using hock burn scores was studied further as a possible simplification strategy (strategy 1). Measurements of footpad dermatitis, hock burn, cleanliness and gait score on-farm correlated moderately to highly with slaughter plant measurements of footpad dermatitis and/or hock burn, supporting substitution of on-farm measurements with slaughter plant data. A simplification analysis was performed using footpad dermatitis, hock burn, cleanliness and gait scores measured on-farm predicted from slaughter plant measurements of footpad dermatitis and hock burn (strategy 2). Simplification strategies were compared with the full assessment protocol. Close agreement was found between the full protocol and both simplification strategies although large confidence intervals were found for specificity of the simplified models. It is concluded that the proposed simplification strategies are encouraging; strategy 1 can reduce the time to complete the on-farm assessment by~1 h (25% to 33% reduction) and strategy 2 can reduce on-farm assessment time by~2 h (50% to 67% reduction). Both simplification strategies should, however, be validated further, and tested on farms with a wide distribution across the different welfare categories of WQ.

Sensitivity of the Welfare Quality® broiler chicken protocol to differences between intensively reared indoor flocks: which factors explain overall classification?

“…However, most European broiler flocks are kept under circumstances similar to those of our flocks. Few models could be produced that explained a substantial proportion of the variance in the measures and these models did not support the correlations between dermatitis and plumage cleanliness previously reported (Arnould and Colin, 2009;De Jong et al, 2015), suggesting that such associations lack extrapolatability. However, the early date of some of our farm visits (up to 10 days before slaughter) and our modest sample size may have decreased our chances of finding associations.…”

“…Also, the protocol distinguishes between birds found dead and those culled, but most participating farmers did not discern between these when recording mortality. Therefore, we collected only a total rejection percentage and a total mortality percentage as previously suggested by De Jong et al (2015). In addition, 'emaciation' and 'rejection' measures were scored at farm level rather than at flock level, as multiple flocks from the same farm arrived at the slaughterhouse in one load, and only one slaughter report was made for the entire farm.…”

“…The alternative manner of rejection and mortality data collection necessitated an alternative integration into the 'absence of disease' criterion, previously developed by De Jong et al (2015). In addition, the calculation for the 'absence of hunger' criterion as described in WQ (2009) contains an error, so we used a corrected version Buijs, Ampe and Tuyttens proposed by De Jong et al (2015). Also, WQ (2009) does not detail how the five-point scale used for the lameness measure should be recoded into the three classes needed for the integration.…”

“…Previous studies have suggested a correlation between dermatitis and plumage cleanliness (Arnould and Colin, 2009;De Jong et al, 2015) or litter quality (Bassler et al, 2013), but these studies differ considering a possible correlation between dermatitis and lameness. Thus, the stability of such correlations still needs confirmation.…”

Early warning of footpad dermatitis and hockburn in broiler chicken flocks using optical flow, bodyweight and water consumption

“…Chickens reared for meat frequently live for only 33–42 days and as measures of welfare, producers use either postmortem measures of the cross-sectional prevalence of footpad dermatitis, hockburn and breast blisters recorded at slaughter (SCAHAW 2000, Haslam and others, 2007, Allain and others 2009, Hepworth and others 2010) or labour-intensive methods such as manually sampling birds (Ekstrand and others 1998, de Jong and others 2012, de Jong and others 2016) that give only a snapshot of the state of a flock at a particular time.…”