The Impact of Marbling on
Production Traits and Carcass Composition
Derek Petry, PhD, Gnesus Inc.
Swine breeding programs have traditionally been focused on production efficiencies (i.e. growth rate and feed conversion) and leanness of the carcass. This focus has led to dramatic improvement in production efficiency and feed conversion. More recently, the market is starting to shift in that marbling and meat quality are growing in importance for consumers, packers and processors.
However, there is much debate on whether selecting on marbling is detrimental to production traits causing pigs to be inefficient. It has been shown that pork quality traits are low to moderately heritable and difficult to measure, while carcass composition traits are highly heritable and easy to measure (Ciobanu et al., 2011). However, relationships between pork quality and production traits/carcass composition are not as clear.
Genetic improvement of production traits, carcass composition, and meat quality requires understanding the genetic control of these traits. Meat quality traits such as color or marbling can be difficult (because it has to be measured on a carcass) and expensive to measure, however newer technologies like ultrasound make it possible to measure intramuscular fat as an indicator of carcass marbling. Understanding the genetic control of meat quality traits and their relationship with production traits and carcass composition is needed to implement a successful breeding strategy that incorporates pork quality.
A study by Miar et al. (2014) estimated genetic and phenotypic parameters between performance traits with meat quality and carcass characteristics in commercial pigs. It was concluded that selection for weight coming out of the nursery would improve pork quality traits. Average daily gain, which is one of the main selection criteria in genetic programs, had no significant genetic correlations with any of the pork quality traits, indicating that deterioration of pork quality was not occurring. Selection for marbling will slightly improve other pork quality traits (i.e. color and pH) but selection for feed conversion decreases pork quality by making pork lighter in color. Further, selection for leaner carcasses will increase cooking loss and paleness of hams. This indicates that if pork quality is not emphasized in the genetic program then the eating experience will deteriorate.
The question – Can you include marbling in your selection program and still improve production traits? – is verified by the work of Miar.
Marbling is one of the most important appearance factors used by consumers to evaluate quality of fresh pork, along with color. So, if we produce pork that no one wants to eat how will we ever change the demand? Having a long-term vision of where a genetic program needs to go is a balance of production traits, carcass composition, and pork quality.
As consumers continue to pay more attention on the eating experience of pork, it is critical to have pork quality as part of the selection objective. Genesus is committed to improving carcass merit and pork quality, conducting weekly assessments since 1998. Having a focus on pork quality will ensure that our customers have the ultimate consistent eating experience.
Ciobanu, D., S.M. Lonergan, E.J. Huff-Lonergan. (2011) Genetics of meat quality and carcass traits, In: The Genetics of the Pig. Rothschild M.F., Rubinsky A., ed. CAB Int, New York, NY. P. 355-389.
Miar, Y., G. Plastow, H. Bruce, S. Moore, G. Manafiazar, R. Kemp, P. Charagu, A. Huisman, B. van Haandel, C. Zhang, R. McKay, and Z. Wang. (2014) Genetic and Phenotypic Correlations between Performance Traits with Meat Quality and Carcass Characteristics in Commercial Crossbred Pigs.
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