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

There is a large demand for holistic welfare assessment systems that result in a singular balanced summary of welfare. The Welfare Quality® (WQ) broiler protocol summarizes 18 welfare measures into four principles ('good feeding', 'good housing', 'good health' and 'appropriate behaviour'), which are then integrated into one overall category ('excellent', 'enhanced', 'acceptable' or 'not classified'). But the protocol is time consuming which hampers implementation. Furthermore, WQ's aim to assess animal welfare in a wide range of husbandry systems may decrease its ability to discriminate between flocks from the same system. We applied the protocol in the context of intensive indoor rearing to assess whether it discriminated sufficiently between flocks, could be shortened without losing essential information, and provided a balanced summary of welfare. The vast majority of the flocks (88%) received the same overall classification (acceptable) whilst all other flocks received an adjacent classification (enhanced), suggesting poor discriminative capacity. For 95% of the flocks overall classification was explained by two measures only ('drinker space' and 'stocking density'). A system based on these two measures would reduce assessment time from 3.5 h to a few minutes. However, both measures' validity can be questioned as they are risk factors for poor welfare rather than animal-based outcome measures and they suffer from methodological weaknesses. Furthermore, the possibility for such an extreme simplification raises doubts on whether the overall classification reflects a balanced summary of different welfare aspects. In line with this, overall classification was not affected by replacing single measures within the 'good health' and 'appropriate behaviour' principles with realistically attainable minima or maxima for intensively reared flocks. Even replacing either of these two principles entirely with their realistically obtainable minimum or maximum did not affect classification. Such insensitivity to change may discourage attempts to improve the welfare of intensively reared flocks when assessments are made based on the overall classification. This calls for an adjustment of the classification system, which is currently being developed by the Welfare Quality Network.

Effect of rubber flooring on group-housed sows' gait and claw and skin lesions.

This study evaluated the influence of floor type on sow welfare in terms of lameness, claw lesions, and skin lesions. In a 2 × 3 factorial design, we have investigated the effect of rubber coverings on concrete floors and the effect of 3 levels of dietary zinc supplementation on locomotion and claw and skin lesions in group-housed sows. Six groups of 21 ± 4 hybrid sows were monitored during 3 successive reproductive cycles. The sows were group housed from d 28 after insemination (d 0) until 1 wk before expected farrowing date (d 108) in pens with either exposed concrete floors or concrete floors covered with rubber in part of the lying area and the fully slatted area. During each reproductive cycle, locomotion and skin lesions were assessed 4 times (d 28, 50, 108, and 140) and claw lesions were assessed twice (d 50 and 140). Results are given as least squares means ± SE. Locomotion and claw scores were given in millimeters, on analog scales of 150 and 160 mm, respectively. Here, we report on the effect of floor type, which did not interact with dietary zinc concentration ( > 0.10 for all variables). At move to group (d 28) and mid gestation (d 50), no differences between floor treatments were seen in locomotion ( > 0.10). At the end of gestation (d 108), sows housed on rubber flooring scored 9.9 ± 4.1 mm better on gait ( < 0.001). Regarding claw disorders, both parameters "heel overgrowth and erosion" (difference of 4.6 ± 1.8 mm; = 0.01) and "heel-sole crack" (difference of 3.1 ± 1.5 mm; = 0.04) scores were better for sows on rubber flooring at mid gestation (d 50). However, sows on rubber flooring scored worse for "vertical cracks in the wall horn" (difference of 3.4 ± 1.7 mm; = 0.04). At the end of lactation (d 140), both "white line" (difference of 2.9 ± 1 mm; = 0.02) and "claw length" (difference of 4.7 ± 1.4 mm; < 0.001) had better scores on rubber flooring. No differences for skin lesions were observed between floor treatments. The improved scores for gait toward the end of gestation and some types of claw disorders at mid gestation suggest that rubber flooring in group housing has a beneficial effect on the overall leg health of sows. The documented increase in vertical cracks in the wall horn at d 50 requires further investigation.

Effect of surgical castration, immunocastration and chicory-diet on the meat quality and palatability of boars.

This study evaluates 1) carcass quality, meat quality and palatability for barrows, immunocastrates and boars and 2) the effect of chicory supplemented feed during 10 days before slaughter on boar meat quality. At comparable carcass weights, estimated carcass lean meat percentage was higher in immunocastrates and boars than in barrows. Muscle thickness was higher for immunocastrates and barrows compared to boars, while fat thickness was lowest for immunocastrates and boars. Barrows, immunocastrates and boars differed in water holding capacity and boar taint. Home consumer panels were conducted to evaluate palatability. The consumers did detect differences in tenderness and juiciness, but not for boar taint. The chicory feed supplemented in boar feed decreased skatole concentration in backfat, without largely influencing meat quality or palatability. Not only boar taint, but also carcass and meat quality should be considered when evaluating alternatives for surgical castration.