Abstract: | Four consecutive studies were carried out over a 3-year period to assess the health and welfare implications of housing finishing pigs in either fully-slatted or straw-bedded accommodation. In each study, 1024 (Large White × Landrace) × Large White pigs, housed in pen groups of 32, were fed ad libitum from 34 kg to slaughter at 104 kg live weight. Eight batches of pigs were received in each study and allocated alternately to fill one room of four pens in each house. Data were collected on a range of welfare parameters. Lameness (P < 0.001) and bitten tails (P < 0.001) were more prevalent health problems in the fully-slatted system, whilst in the straw-bedded system pigs showed more respiratory (P < 0.01) and PMWS-type symptoms (P < 0.01). Acute phase protein titres at slaughter were higher in pigs from the fully-slatted system (P < 0.001). Skin lesion score did not differ between systems; however, bursitis was more severe in pigs in the fully-slatted system (P < 0.001). Pigs in the straw-bedded system had poorer hygiene scores (P < 0.001), but the magnitude of this difference varied between studies depending on season. Pigs with straw were more active (P < 0.001), spending a large proportion of time manipulating straw. In the absence of straw, pigs spent more time in behaviour directed at other pigs (P < 0.001) and the pen components (P < 0.001). Post-slaughter assessment showed no system differences in lung lesions and cardiac scores, or osteochondrosis. Pigs with straw had more severe toe erosions on the foot (P < 0.001), whilst pigs without straw had more severe sole (P < 0.001) and heel erosions (P < 0.001). Gastric lesion scores were lower in the fully-slatted system (P < 0.001). The results show both advantages and disadvantages to each of the housing systems for pig welfare. |