| Abstrakt: |
Objectives were to determine the effects of marketing group on quality and variability of belly and adipose tissue quality traits of pigs sourced from differing production focuses (lean vs. quality). Pigs (n = 8,042) raised in 8 barns representing 2 seasons (cold and hot) were used. Three groups were marketed from each barn with 2 barns per production focus marketed per season. Data were collected on 7,684 carcasses at a commercial abattoir. Fresh belly characteristics, American Oil Chemists' Society iodine value (AOCS-IV), and near-infrared iodine value were measured on a targeted 50, 10, and 100% of carcasses, respectively. Data were analyzed as a split-plot design in the MIXED procedure of SAS 9.4 with production focus as the whole-plot factor and marketing group as the split-plot factor. Barn (block), season, and sex were random variables. A multivariance model was fit using the REPEATED statement with the marketing group × production focus interaction as the grouping variable. Variances for production focus and marketing groups were calculated using the MEANS procedure. Homogeneity of variance was tested on raw data using the Levene's test of the GLM procedure. Among quality focus carcasses, marketing group 3 bellies weighed less (P ≤ 0.03) than those from either marketing group 1 or 2, but there was no difference (P ≥ 0.99) among marketing groups of the lean focus carcasses. There was no effect (P ≥ 0.11) of production focus on fresh belly measures, SFA, or iodine value (IV), but lean focus carcasses had decreased (P = 0.04) total MUFA and increased (P < 0.01) total PUFA compared with quality focus carcasses. Marketing group did not affect (P ≥ 0.10) fresh belly dimensions, total SFA, total MUFA, total PUFA, or IV. Belly weight, flop score, width, and all depth measurements were less variable (P ≤ 0.01); whereas, belly length, total SFA, and total MUFA were more variable (P < 0.0001) in lean focus carcasses than in quality focus carcasses. There was no difference (P ≥ 0.17) in total PUFA or AOCS-IV variability between production focuses. Variance of flop score, total MUFA, and total PUFA were not equal (P ≤ 0.01) among marketing groups. Belly weight, length, width, and depth measurements; SFA; or IV variance did not differ (P ≥ 0.06) among marketing groups. Although a multiple-marketing strategy was effective at minimizing differences in belly characteristics, differences in the variability of these traits exist among marketing groups and are likely dependent on the production system used. [ABSTRACT FROM AUTHOR] |
