Table 1.
Description of the 74 breed-to-finish pig systems studied. (The label categories are approximately ordered by the degree of welfare standards required by each, with more demanding categories exceeding the standards of lower categories. From least to most demanding the categories are no assurance or labelling (none), Red tractor (including Quality Meat Scotland; QMS), RSPCA assured, free range, woodland and Organic. If systems met the requirements for multiple labels, they were included in the most demanding label type, for example: free-range systems that are also RSPCA assured were included in the free-range category. Any relevant label standards or guidelines can be found in the citations in the first column. The UK pigs by label type column show the percentage of the total slaughtered fattening pigs in the UK in 2021 [40] with each label type [41,42]. These sum to more than 100% as farms often have multiple label types. The pigs in this study column show the annual slaughtered fattening pigs from our 74 systems, summed by label type and rounded to the nearest 1000, and our estimate of the percentage of all slaughtered pigs belonging to that label type which they represent. In total, our study covers 5% of UK slaughtered fattening pigs.)
| label type | breeding husbandry type | rearing and finishing husbandry type | number of breed-to-finish systems | UK pigs by label type (%) | pigs in this study (% of UK total pigs) |
|---|---|---|---|---|---|
| none [43] | typically indoors. Farrowing crates are permitted | typically indoors. Fully slatted floors are permitted | 4 | 5 | 38 000 (7%) |
| Red tractor [44] including QMS [45] | typically indoors. Farrowing crates are permitted | typically indoors. Fully slatted floors are permitted | 31 | 95 | 479 000 (5%) |
| RSPCA assured [46] | farrowing can be indoors, but sows must be allowed to turn around at all times | pigs must have access to unperforated floors and sufficient bedding | 12 (of which 10 are also Red tractor) | unknown | 222 000 (unknown) |
| free range | always outdoors | 18 (of which 15 are also Red tractor and RSPCA assured) | 2.5 | 165 000 (60%) | |
| woodland | pigs are kept at least with partial tree cover, but farms could also include some indoor housing | 3 (of which 2 are also free range) | unknown | 13 000 (unknown) | |
| Organic [47,48] | always outdoors | 6 (of which 5 are also Red tractor, RSPCA assured and all 6 are free range) | 0.6 | 31 000 (47%) | |