Assessment of welfare of Brazilian and Belgian broiler flocks using the Welfare Quality protocol.

The Welfare Quality consortium has proposed a science-based protocol for assessing broiler chicken welfare on farms. Innovative features make the protocols particularly suited for comparative studies, such as the focus on animal-based welfare measures and an integration procedure for calculating an overall welfare status. These protocols reflect the scientific status up to 2009 but are meant to be updated on the basis of inter alia implementation studies. Because only few such studies have been done, we applied the Welfare Quality protocol to compare the welfare of broiler flocks in Belgium (representing a typical European Union (EU) country which implies stringent animal welfare legislation) versus Brazil (the major broiler meat exporter to the EU and with minimal animal welfare legislation). Two trained observers performed broiler Welfare Quality assessments on a total of 22 farms in Belgium and south Brazil. All of the farms produced for the EU market. Although the overall welfare was categorized as 'acceptable' on all farms, many country differences were observed at the level of the welfare principles, criteria, and measures. Brazilian farms obtained higher scores for 3 of the 4 welfare principles: 'good feeding' (P = 0.007), 'good housing' (P < 0.001), and 'good health' (P = 0.005). Four of the 10 welfare criteria scores were, or tended to be, higher on Brazilian than Belgian farms: 'absence of prolonged thirst' (P < 0.001), 'ease of movement' (P < 0.001), 'absence of injuries' (P = 0.002), and 'positive emotional state' (P = 0.055). The only criteria with a higher score for the Belgian farms than their Brazilian counterparts were 'absence of prolonged hunger' (P = 0.048) and 'good human-animal relationship' (P = 0.002). Application of the Welfare Quality protocol has raised several concerns about the validity, reliability, and discriminatory potential of the protocol. The results also call for more research into the effect of animal welfare legislation as broiler welfare on the south Brazilian farms appeared to be superior to that on the Belgian farms. Animal-based welfare assessments on a larger sample of farms are needed to evaluate to what extent these findings may be generalized.

Performance of an animal-based test of thirst in commercial broiler chicken farms.

Animal-based measures of thirst are currently absent from animal welfare monitoring schemes due to the lack of a well-validated indicator applicable for on-farm use. In the present study, an on-farm test based on voluntary water consumption from an unfamiliar open drinker was validated in a (semi-)commercial setting. To investigate the effect of thirst on water consumption, we subjected 4 flocks of 1,500 broilers to either 0 or 12 h of water deprivation and subsequently measured the amount of water that small subgroups consumed after the deprivation period (first experiment). Broilers that were water deprived before the test drank more than control broilers (P < 0.001). In a second experiment, a similar test was performed using 20 commercial broiler flocks in Belgium and Brazil. After a pretreatment water consumption test, the birds were subjected to 0 or 6 h of water deprivation, and a posttreatment water consumption test was conducted. Only in Brazil, deprived birds drank significantly more than controls in the posttreatment water consumption test (P < 0.001). A tendency for a difference was found in Belgium (P = 0.083). Pre- and posttreatment water consumption was higher in Brazil than in Belgium (P < 0.001). Stocking density and temperature influenced, respectively, the pretreatment and the control's posttreatment water consumption in Brazil, but not in Belgium. These results indicate that the water consumption test is sufficiently sensitive to discriminate between control and 12 h deprived flocks, and in Brazil even between control and 6 h deprived birds. The location of the test within the house did not affect the amount of water consumed in either experiment, suggesting that this variable does not have to be standardized. However, the amount of water consumed by broilers able to drink freely for a long period depended on indoor climatic variables (in Brazil only) and possibly genotype. This suggests that these variables need to be considered when interpreting the test outcome in terms of the thirst level experienced by the broilers.

Automated assessment of footpad dermatitis in broiler chickens at the slaughter-line: evaluation and correspondence with human expert scores.

Footpad dermatitis is increasingly used as an indicator of decreased broiler welfare, and automation of dermatitis monitoring potentially reduces the effort needed to monitor commercial flocks. In this study we evaluated a prototype system for the automatic assessment of footpad dermatitis in broiler chickens by comparing the automatic assessment with a human expert assessment. The expert aimed at selecting 2 times (different period) 20 broilers per footpad dermatitis category (5 categories in total), from 2 different flocks of 38-d-old broilers on an experimental farm. Two days later these broilers were transported to the slaughterhouse, where footpad dermatitis was assessed by the automatic system. Subsequently the footpads were reassessed by the same expert that had selected the birds. Automatic scores were only weakly correlated with scores given by the expert on-farm (r = 0.54) and at the slaughterhouse (r = 0.59). Manual evaluation of the photographs on which the automatic system based its scores revealed several errors. For 41.1% of the birds, the automatic system assessed only one of the footpads, whereas for 15.2% neither footpad was assessed. For 49.4% of the birds, scores were based on partially incorrectly identified areas. When data from such incomplete and obviously incorrect assessments were discarded, stronger correlations between automatic and expert scores were found (r = 0.68 and r = 0.74 for expert scores given on-farm and at-slaughter, respectively). Footpads that were missed by the automatic system were more likely to receive a high expert score at slaughter (P = 0.02). However, average flock scores did not differ greatly between automatic and expert scores. The prototype system for automatic dermatitis assessment needs to be improved on several points if it is to replace expert assessment of footpad dermatitis.

Dehydration indicators for broiler chickens at slaughter.

Freedom of (prolonged) thirst is considered to be of paramount importance for animal welfare. This emotion normally results from dehydration, which can be measured using physiological indicators. Because no reliable physiological indicator for thirst was available for broilers, we aimed to identify such a measure in this study. This indicator would ideally be integrated into quality control systems in commercial slaughter plants. In the first experiment, water deprivation was manipulated systematically by withdrawing water for different durations (total water withdrawal for 0 (control), 24, 36, or 48 h, or a 10-d period with restricted access to water for 2 times 10 min per day). A significant decrease in drained blood content and BW occurred from 36 h of total water deprivation onward (both P = 0.03), whereas long-term restricted access tended to decrease drained blood content (P = 0.05). No effect of water deprivation or restriction on skin turgor was found. In the second experiment, water was withdrawn for 0 (control), 6, 12, 24, or 48 h. Plasma chloride concentration was increased after 6 h of water withdrawal, but did not rise further with longer withdrawal. If assessed at slaughter, chloride will thus mainly reflect the catching-to-slaughter interval. In contrast, plasma creatinine and hematocrit levels showed a numerical decrease after 6 h of water withdrawal, but rose again after prolonged withdrawal. Plasma creatinine values were significantly higher in 24-h-deprived birds than in 6-h-deprived birds (P < 0.01), allowing for discernment between water withdrawal during catching and transport from dehydration that had occurred on the farm. Blood sodium concentrations and plasma osmolality showed a steady increment between 0 and 24 h of water deprivation (P < 0.001 and P < 0.001 for both), and may thus be used to assess the combined effects of water deprivation on farm and during the catching-to-slaughter interval. These findings may form the basis of an on-farm or at-slaughter test that could be included in integrated animal welfare assessment schemes.