Meat quality of fully or partly outdoor reared pigs in organic production

Outdoor production on pasture is considered an option in organic pig production. The aim of the present trial was to study the influence of feeding strategies combining outdoor and indoor rearing on pig meat quality. The experiment was carried out with 245 pigs in 5 replicates, and commenced following weaning at day 52. Five treatments were compared: 1) pigs fed ad libitum and reared indoors with access to an outdoor concrete area (In-A); 2) pigs fed restrictively on pasture until 40 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-40A); 3) pigs fed restrictively on pasture until 80 kg body weight and then kept indoors with access to an outdoor concrete area and fed ad libitum until slaughter (In-80A); 4) pigs reared on pasture and fed restrictively during the whole period of growth (Out-R); and 5) pigs reared on pasture and fed ad libitum during the whole period of growth (Out-A). All pigs had free access to roughage (clover-grass silage/fresh clover grass). Restrictive feeding in the weight range from weaning to 40 kg body weight (In-40A) resulted in a reduced daily gain; however, following transfer to indoor facilities and ad libitum feeding these pigs compensated in growth and the overall daily gain did not differ from the In-A control pigs. Pigs fed restrictively from weaning to 80 kg body weight were unable to compensate completely following transfer to indoor facilities. Out-R pigs had the lowest overall daily gain, while In-A pigs and Out-A pigs had similar daily gain. Meat quality assessments were performed on longissimus dorsi (LD) samples from a subsample of 100 pigs (2 castrates and 2 female pigs from each treatment in each replicate). Compared to meat from either ad libitum treatments (In-A and Out-A), meat from Out-R and In-80A pigs was less red due to a lower pigmentation, and had a higher ratio of polyunsaturated: saturated fatty acids. In addition, Out-R female pigs had numerically (6-10 Newton) higher shear force than In-A and Out-A. Treatments did not affect the concentration of alpha-tocopherol of meat. Introducing a finishing period with free access to concentrates following 40 kg body weight until slaughter prevented the deterioration in meat quality. However, a finishing period following 80 kg body weight was not sufficient. In conclusion, ad libitum feeding in the organic production system gave superior meat quality compared to a restrictive feeding strategy. However, including a finishing period indoors with ad libitum feeding of concentrates may prevent the detrimental effect of restrictive feeding on meat quality.