PSV-1 Pasture Does Not Impact Pork Quality of Finishing Hogs

Abstract

Abstract Sales of certified organic pork continue to increase, and an increasing number of young farmers are looking to rear hogs with organic or other niche labeling claims that require outdoor access. There is limited research available to support pastured pork operations in developing best management practices for rearing pigs in outdoor environments. The goal of this study was to evaluate the impact of housing on swine performance and pork quality and to build best management strategies for raising hogs on pasture. Pigs (n = 50) from the same sire and farrowing cohort were obtained from 10 separate litters. Pigs were grouped into separate treatments according to average body weights (BW) with equal sex rations among both groups: Indoor (n = 25), and Outdoor (n = 25), with 5 hogs per pen within each treatment. The Indoor groups were housed on 7m2 of solid concrete flooring in a ventilation-controlled barn; the Outdoor groups were housed on native grass pasture with pen size being 23m2, and a third shaded with 40% shade cloth. Outdoor pens were rotated to new grass every 14 days to manage soil destruction, while Indoor pigs remained in original pens for the duration of the project. Water access was provided via a nipple drinker system and fed a standard grow-finish ration ad libitum for both groups. All pigs were slaughtered at 26 weeks of age, with the Indoor group averaging BW of 126kg, and the Outdoor group averaging BW of 111kg (P < 0.05). Hot carcass weights were also larger (P < 0.001) of the Indoor group. All pork quality measurements were taken at the 10th rib. Color and marbling scores were not shown to vary between the treatment groups (P ≥ 0.17). Colorimeter values (L*, A*, B*) were similar across treatments as well (P ≥ 0.41). However, loin eye area exhibited a trend with the Outdoor group having a smaller average size (P = 0.07) In addition to this, pH values were also shown to vary at 0h (P = 0.03), 6h (P = 0.01), and 24h (P < 0.01) postmortem, with the Indoor group having the higher ultimate pH. Based on these data, pasture reduced final market size and loin eye area of hogs, but not overall pork quality. Although pH was reduced for the Outdoor group, no values showed a rapid decline in pH that would indicate a PSE pork product. Further, average pH between treatments were within 0.2 at all sampling times. Further research is needed to evaluate efficacy of best management practices to improve efficiency of pig growth rate on pasture and to ensure that pork quality will not be reduced.