Rearing hogs on pasture minimally impacts pork composition

Abstract

Managing swine on pasture is increasing in popularity for both the consumer and producer. This interest appears to be driven by an effort to create an improved perception of environmentally sustainable practices and increased animal welfare, while keeping start-up costs low. However, evidence-based guidance on pasture management practices that support quality pork production and environmentally sustainable procedures are lacking. The objective of this work was to quantify the impact of pasture rearing on pig growth efficiency and pork quality. In this pilot study, twenty pigs similar in genetics, age, weight, and sex ratio were divided across Indoor (n = 10) and Outdoor (n = 10) housing environments. Pigs were weighed every fourteen days and harvested upon reaching an average weight of 113kg. Average starting body weights were similar between both groups (P = 0.98). Carcass quality was evaluated by measuring pH, loin eye area (LEA), back fat (BF) thickness, subjective color and marbling scores, and colorimetry (CIE color space (L*, a*, b*)) at the 10th rib. Final body weights at slaughter also showed no significant variation between housing groups (P = 0.98). No differences were observed in pork quality: pH 0h (P = 0.53), 6h (P = 0.29), 12h (P = 0.80), and 24h (P = 0.07) postmortem, LEA (P = 0.44), color (P = 0.73), and marbling (P = 0.40). However, hogs raised indoors had an increase in BF thickness (P = 0.04). Based on this pilot study, outdoor rearing conditions did not have significant impacts on pork quality. Further research will help to determine the impact that rearing scheme has on pH and back fat.