Lo L L, McLaren D G, McKeith F K, Fernando R L, Novakofski J
Department of Animal Sciences, University of Illinois, Urbana 61801.
J Anim Sci. 1992 Aug;70(8):2373-86. doi: 10.2527/1992.7082373x.
Knowledge of breed effects on carcass and pork quality traits is required to develop commercial crossbreeding programs that emphasize product quality. A 2 x 2 diallel mating system involving Landrace and Duroc pigs was used to estimate individual heterosis, direct breed effects and reciprocal cross differences for post-weaning growth, real-time ultrasound, carcass, and pork quality traits. Data from 5,649 pigs and 960 carcasses representing 65 and 49 sires, respectively, were analyzed assuming animal models. Duroc-sired pigs had 2.1 cm shorter carcasses with 7.3 mm less 10th rib backfat (BF), 4.4 cm2 larger longissimus muscle area (LMA), yielded 2.1 kg more estimated fat standardized lean (FSL), gained 16.5 g more estimated lean per day of age (LDOA), and had 1.0% less water (PWAT) and 1.9% more intramuscular fat (IMF) in the longissimus muscle than did Landrace-sired pigs (P less than .01), adjusted to an off-farm live weight of 111 kg. Reciprocal cross differences were detected for BF, LMA, FSL, LDOA and for subjective marbling, firmness, and muscling scores (P less than .01). Durocsired F1 barrows had 6.3 mm less BF and 5.9 cm2 larger LMA, yielded 3.2 kg more FSL, gained 22.3 g more LDOA, and had less marbling in the longissimus muscle and heavier ham muscling than reciprocal cross barrows. Heterosis estimates (P less than .05) were 27.6 g/d (3.2%) for ADG, -5.8 d (-3.6%) for off-test age, 2.7 cm (3.4%) for carcass length, 1.5 kg (7.2%) for FSL, 14.7 g (5.7%) for LDOA, -.07 (-3.6%) for muscle color, -.5% (-13.2%) for IMF, and .3% (.3%) for PWAT. Breed effects were not detected (P greater than .10) for muscle pH, cooking loss, shear value, and water-holding capacity or for eating quality traits. Reciprocal cross differences suggest an advantage in using the Duroc as a terminal sire, but improved carcass composition and higher intramuscular fat did not seem to affect eating quality traits.
要制定注重产品质量的商业杂交育种计划，就需要了解品种对胴体和猪肉品质性状的影响。采用包含长白猪和杜洛克猪的2×2双列杂交交配系统，来估计断奶后生长、实时超声、胴体和猪肉品质性状的个体杂种优势、直接品种效应和正反交差异。分别假设动物模型，对来自5649头猪和960头胴体的数据进行了分析，这些猪和胴体分别代表65头和49头公猪。与长白猪所生的猪相比，杜洛克猪所生的猪胴体短2.1厘米，第10肋背膘厚（BF）少7.3毫米，背最长肌面积（LMA）大4.4平方厘米，估计脂肪标准化瘦肉（FSL）多2.1千克，每日龄估计瘦肉增加量（LDOA）多16.5克，背最长肌水分含量（PWAT）少1.0%，肌内脂肪（IMF）多1.9%（P小于0.01），调整后的场外活重为111千克。在BF、LMA、FSL、LDOA以及主观大理石纹、坚实度和肌肉评分方面检测到了正反交差异（P小于0.01）。杜洛克猪所生的F1公猪的BF少6.3毫米，LMA大5.9平方厘米，FSL多3.2千克，LDOA多22.3克，背最长肌大理石纹少，火腿肌肉更发达。杂种优势估计值（P小于0.05）为：平均日增重（ADG）27.6克/天（3.2%），测定结束时年龄-5.8天（-3.6%），胴体长度2.7厘米（3.4%），FSL 1.5千克（7.2%），LDOA 14.7克（5.7%），肌肉颜色-0.07（-3.6%），IMF -0.5%（-13.2%），PWAT 0.3%（0.3%）。在肌肉pH值、烹饪损失、剪切值、持水能力或食用品质性状方面未检测到品种效应（P大于0.10）。正反交差异表明，以杜洛克猪作为终端父本具有优势，但胴体组成的改善和较高的肌内脂肪似乎并未影响食用品质性状。
