Overholt M F, Arkfeld E K, Wilson K B, Mohrhauser D A, King D A, Wheeler T L, Dilger A C, Shackelford S D, Boler D D
J Anim Sci. 2016 Dec;94(12):5168-5176. doi: 10.2527/jas.2016-0975.
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 ( = 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 ( ≤ 0.03) than those from either marketing group 1 or 2, but there was no difference ( ≥ 0.99) among marketing groups of the lean focus carcasses. There was no effect ( ≥ 0.11) of production focus on fresh belly measures, SFA, or iodine value (IV), but lean focus carcasses had decreased ( = 0.04) total MUFA and increased ( < 0.01) total PUFA compared with quality focus carcasses. Marketing group did not affect ( ≥ 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 ( ≤ 0.01); whereas, belly length, total SFA, and total MUFA were more variable ( < 0.0001) in lean focus carcasses than in quality focus carcasses. There was no difference ( ≥ 0.17) in total PUFA or AOCS-IV variability between production focuses. Variance of flop score, total MUFA, and total PUFA were not equal ( ≤ 0.01) among marketing groups. Belly weight, length, width, and depth measurements; SFA; or IV variance did not differ ( ≥ 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.
目的是确定销售组对来自不同生产重点(瘦肉型与品质型)的猪腹部和脂肪组织品质性状的质量和变异性的影响。使用了在代表两个季节(寒冷和炎热)的8个猪舍中饲养的8042头猪。每个猪舍销售三组,每个季节每个生产重点销售两个猪舍。在一家商业屠宰场收集了7684头胴体的数据。分别对目标50%、10%和100%的胴体测量新鲜腹部特征、美国油脂化学家协会碘值(AOCS-IV)和近红外碘值。数据在SAS 9.4的MIXED过程中作为裂区设计进行分析,生产重点作为整区因素,销售组作为裂区因素。猪舍(区组)、季节和性别为随机变量。使用REPEATED语句拟合多变量模型,销售组×生产重点交互作用作为分组变量。使用MEANS过程计算生产重点和销售组的方差。使用GLM过程中的Levene检验对原始数据进行方差齐性检验。在品质重点的胴体中,销售组3的腹部重量比销售组1或2的轻(P≤0.03),但在瘦肉重点的胴体销售组之间没有差异(P≥0.99)。生产重点对新鲜腹部测量、饱和脂肪酸(SFA)或碘值(IV)没有影响(P≥0.11),但与品质重点的胴体相比,瘦肉重点的胴体总单不饱和脂肪酸(MUFA)降低(P = 0.04),总多不饱和脂肪酸(PUFA)增加(P<0.01)。销售组对新鲜腹部尺寸、总SFA、总MUFA、总PUFA或IV没有影响(P≥0.10)。腹部重量、松弛评分、宽度和所有深度测量的变异性较小(P≤0.01);而瘦肉重点的胴体中腹部长度、总SFA和总MUFA的变异性比品质重点的胴体更大(P<0.0001)。生产重点之间总PUFA或AOCS-IV的变异性没有差异(P≥0.17)。销售组之间松弛评分、总MUFA和总PUFA的方差不相等(P≤0.01)。腹部重量、长度、宽度和深度测量;SFA;或IV方差在销售组之间没有差异(P≥0.06)。尽管多销售策略有效地最小化了腹部特征的差异,但这些性状变异性的差异在销售组之间存在,并且可能取决于所使用的生产系统。