Sire Variation in the Severity of the Ham Halo Condition

Abstract

A study was conducted to examine genetic variation in the ham halo condition. The distal portion of the biceps femoris was sampled by taking cores (2.54-cm diameter) from progeny (n = 1,016) from a Duroc meat quality–focused line. Commission Internationale de l ́Éclairage (CIE; “International Commission on Illumination”) color-space values (L*, a*, and b*) and myoglobin concentration were measured on the halo (“Halo”) and inside (“Inside”) portion of each core. The Halo portion of the biceps femoris had greater L* and b* and lesser a* and myoglobin content (all P < 0.001) than the Inside portion. Sires with 11 or more progeny were compared. The sire × muscle-location interaction affected (P < 0.001), L*, a*, and myoglobin concentration. Sire progeny groups differed for each trait in both portions of the muscle, but differences in the Halo portion of the muscle were not mirrored in the Inside portion of the muscle. Similarly, sire group affected the magnitude of the difference in L* (P = 1.4 × 10−4) and a* (P = 9.0 × 10−6) between the Halo and Inside portions of the muscle and tended (P = 0.08) to affect myoglobin content. However, the largest sire-group differences were not necessarily seen in the sires with the highest means for these attributes. Thus, selecting for myoglobin concentration, L*, or a* content in the Halo portion of the biceps femoris muscle would be an effective strategy for reducing the severity of the ham halo condition.