Purpose of this investigation was to deter- mine the nature of a visible spotting defect on the slice of dry-cured ham and assess environ- mental and genetic causes of this frequent problem. A group of 233 pigs from commercial cross-breeding lines, progeny of ten boars and forty seven sows, was raised in a single herd to obtain the Italian Heavy Pig, typically slaugh- tered at 160±10 kg live weight and older than 9 months of age. A quality evaluation of their right dry-cured hams, seasoned according to the Parma P.D.O. protocol, was undertaken. Each ham was cross-sectioned to obtain a slice of Semimembranosus, Semitendinosus and Biceps Femoris muscles. The focused pheno- type was the presence/absence of brownish spots in these muscles, which represent a remarkable meat defect with strong impact on the final sale price. Environmental and man- agement factors were considered in order to evaluate variability related to the phenotype. Animals were raised on two different flooring types (concrete and slatted floor) and a Vitamin C diet was also supplemented in the last 45 days before slaughtering to half of the animals. While the pre-planned environmental effects did not show any significant contribution to the total variability of the phenotype, the genetic analysis showed a near to zero value for heri- tability with a consistent 0.32 repeatability. The proportion of the total phenotypic variance was explained by an important dominance genetic component (0.26) indicating that the techno- logical seasoning process may play a secondary role on the expression of this phenotype.
Genetic and environmental effects on a meat spotting defect in seasoned dry-cured ham
Stella A;
2011
Abstract
Purpose of this investigation was to deter- mine the nature of a visible spotting defect on the slice of dry-cured ham and assess environ- mental and genetic causes of this frequent problem. A group of 233 pigs from commercial cross-breeding lines, progeny of ten boars and forty seven sows, was raised in a single herd to obtain the Italian Heavy Pig, typically slaugh- tered at 160±10 kg live weight and older than 9 months of age. A quality evaluation of their right dry-cured hams, seasoned according to the Parma P.D.O. protocol, was undertaken. Each ham was cross-sectioned to obtain a slice of Semimembranosus, Semitendinosus and Biceps Femoris muscles. The focused pheno- type was the presence/absence of brownish spots in these muscles, which represent a remarkable meat defect with strong impact on the final sale price. Environmental and man- agement factors were considered in order to evaluate variability related to the phenotype. Animals were raised on two different flooring types (concrete and slatted floor) and a Vitamin C diet was also supplemented in the last 45 days before slaughtering to half of the animals. While the pre-planned environmental effects did not show any significant contribution to the total variability of the phenotype, the genetic analysis showed a near to zero value for heri- tability with a consistent 0.32 repeatability. The proportion of the total phenotypic variance was explained by an important dominance genetic component (0.26) indicating that the techno- logical seasoning process may play a secondary role on the expression of this phenotype.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
