Performance, carcass and technological meat quality of pigs in indoor and outdoor production systems

This study aimed to compare different production systems, i.e., the combined effect of outdoor and indoor rearing of pigs and organic diets fed ad libitum or restrictively. Furthermore, the suitability of two breed crosses for outdoor rearing was studied. The effects on performance, carcass and technological quality traits were investigated. During two years, 240 pigs of Duroc x Large White ((DLW)-L-star) and Swedish Landrace x Large White ((LLW)-L-star) were allocated to three production systems: 1) Pigs kept outdoors, fed an organic diluted diet (20% alfalfa roughage) ad libitum; 2) Pigs kept outdoors, strategically fed a diluted organic diet up to a live weight of approximately 80 kg and thereafter an undiluted organic diet ad libitum; 3) Pigs kept indoors, fed an undiluted organic diet restrictively. For outdoor pigs, strategic feeding increased daily weight gain and backfat thickness, compared with feeding a diluted diet throughout (p <= 0.01). (LLW)-L-star pigs in both outdoor systems grew slower than in the indoor system (p <= 0.001), whereas for (DLW)-L-star pigs only outdoor pigs fed the diluted diet had a slower growth rate. Outdoor pigs had lower dressing percentage than indoor pigs. Glycogen content and L-star values in M. longissimus dorsi were higher, whereas b(star) values were lower in meat from pigs in the indoor system. (DLW)-L-star pigs had higher water-holding capacity (lower drip, thawing and cooking losses), lower shear force and higher intramuscular fat content compared with (LLW)-L-star pigs.