Effects of space allowance, roughage supplement, and enrichment provision on growth, carcass weight and meat quality in conventional indoor pig husbandry

Extensification of indoor pig husbandry is increasingly under focus, but effects on meat quality remain to be determined. This study investigated the effects of extensification factors on growth, carcass weight and meat quality of fattening pigs. Three factors were studied on pigs from 30 kg up to slaughter at approximately 120 kg: increase space allowance to 1.4 (S9, n pigs = 108, n samples = 42) or 2.1 (S6, n pigs = 72, n samples = 42) m2 per pig, provision of various enrichments (E, n pigs = 114, n samples = 44), and daily provision of roughage (R, n pigs = 115, n samples = 45). Treatments were compared to a control group with 0.7 m2 per pig and no extra enrichment nor roughage (C, n pigs = 115, n samples = 48). The study was performed over two batches, in spring and in autumn. The treatments had overall no effect on meat quality as measured by temperature and pH, colour, driploss, cooking loss or texture. However, the meat from S9 pigs had a significantly lighter colour than the meat from C, R or E and in addition, pigs from S6 had a higher growth rate (ADG) and carcass weight than C and R. Overall, the treatments had little to no effect on meat quality but increasing space allowance by a factor three notably improved pig growth. In contrast, the experimental batch significantly influenced several parameters of meat quality as well as growth and carcass weight, highlighting that un-controlled factors varying between batches, including seasonal effects, had a greater impact on meat quality than the treatments alone.