Seasonal Effects on Growth Performance and Meat Quality in Berkshire Crosses Reared in Alternative Production System

Seasonality has been found to impact pig production in the United States. Seasonal effects on growth performance, carcass and meat quality traits of Berkshire crosses were evaluated. Over a 2-year period (2015--2017) during fall and spring seasons, 4 trials were conducted.;A total of 171 pigs were used; 53 purebred Berkshire (BB), 78 Tamworth x Berkshire (TB), and 40 Hereford x Berkshire (HB). Piglets farrowed on pasture and were reared in a naturally ventilated hoop structure from weaning to finish. Body weights were collected from d3 to d140 at 28-day intervals and used to calculate growth performance. Pigs were slaughtered at the same age and 113kg of body weights. Backfat thickness, loin muscle area (LMA), and meat quality traits were measured from the longissimus dorsi muscle. Meat quality traits analyzed were marbling, color, pH, and objective color attributes lightness (L*), redness (a*), and yellowness (b*; CIE color system).;There was a season x breed interaction observed in growth performance. The BB pigs had consistently lower weights in fall months versus spring months from weaning to finish. The TB pigs had lower weights in the fall compared to spring, but only at d140 (83.91 +/- 10.82 and 88.44 +/- 9.13 kg, respectively). Hereford sired pigs displayed no seasonal effects on growth performance. Breed had no effect on any of the meat quality traits. However, season had an effect on pH (p < 0.001) and lightness (L*) (p < 0.01). When analyzing carcass traits, fall seasons were characterized by thicker back fat at the tenth (p < .001) and lower lumbar (p < 0.01) ribs and larger loin muscle area (p < 0.001) for all pigs in this study. A season x breed interaction (p < 0.05) was observed in the thickness of backfat at the tenth rib (BF10) for the BB pigs.;The season x breed interaction suggests Berkshire purebreds are not well suited for outdoor production in colder climates. Crossbreeding appears to counteract the inferior seasonal growth performance of purebred Berkshires without negatively influencing meat quality. Further studies should be done to assess the validity of these findings and their implications on sensory characteristics.