Is Customising Pork Primal Value an Opportunity?
Bob Kemp,VP Genetic Programs and R&D, Genesus Inc.
In the last several years the value of different pork primals varied considerably in different markets. For example, hams are dominant in the Spanish market, loins are highly valued in Japanese market and the US/Canadian markets have seen loins and bellies both highly valued at different times. This always leads to the discussion regarding genetic opportunities to customise primal value.
First, we need to define primal value. This is somewhat market dependent but generally can be split into composition and quality parameters. Composition refers to the relative amounts of fat, lean and/or bone in a specific primal. Quality parameters are the usual ones, namely meat colour, pH and intramuscular fat (IMF). However, IMF needs to be expanded to include another important quality parameter, fatty acid composition.
Both IMF and fatty acid composition impact nutritional and consumer satisfaction properties of pork (Wood et al. 2004 Meat Science 66:21-32). An excellent example is the dry-cured ham in the Mediterranean area where hams containing higher levels of a specific fatty acid, namely oleic acid receive a premium at the consumer level (Ros-Freixedes et al. 2014 doi:10.2527/jas2014-8202). Thus, interest in including primal composition, IMF and fatty acid composition in the selection goal of genetic programs has increased in the last few years.
For the sake of simplicity of this article we will limit the topic to fatty acid composition and IMF. These traits are difficult and expensive to measure so measurement is generally done on a small sample of animals, on single muscles or locations (e.g. between the 3rd/4th last rib of longissimus muscle) and/or by indirect methods (e.g. ultrasound preditciton of IMF in live animals or carcasses). When discussing IMF, the general assumption is that it is measured in the loin primal, specifically the longissimus muscle (LM) as that is a standard muscle for meat quality parameters.
Research results have shown that fatty acid composition can differ among locations within the LM (Faucitano et al. 2004. Can. J. Anim. Sci. 84:57-61), among different muscles (e.g. Kim et al. 2008. J. Anim. Sci. 21:138-143) and between IMF and backfat (e.g. Bosch et al. 2012 Meat Sci. 91:358-363). Additionally, IMF and fatty acid composition traits have been shown to be moderately to highly heritable (e.g. Sellier et al. 2010. Animal 4:497-504) so will respond to direct selection. Thus, the important question for genetic approaches to increasing value of different primals is; by selecting to improve IMF or fatty acid composition in one primal or muscle location (e.g. loin) what is the impact on IMF and/or fatty acid composition and thus value in other primals.
A study reported by Ros-Freixedes et al. (2014 doi:10.2527/jas2014-8202) gives an excellent example of the necessary considerations of selection at different muscle and/or backfat locations. They examined the genetic associations among measurements of IMF in 3 muscles (2 in the ham and 1 in the loin primal) and among fatty acid composition in the muscles and backfat in the loin primal. The IMF and fatty acid composition associations were positive and high among one ham and loin muscle but positive and very low with the second ham muscle. Likewise, fatty acid composition between muscles was generally higher than between muscles and backfat. They also suggested that location of the backfat sample could be important since the association between the muscle and backfat measure was higher when the backfat location was adjacent to the muscle. They concluded that the genetic associations among IMF and fatty acid composition across muscles and fat tissues are positive, but variable enough that they need to be considered in genetic evaluation and improvement programs including on IMF and fatty acid composition.
Genesus Inc. has had a long and focused effort on improving pork quality. The next logical step is to examine the opportunities for increasing primal composition and quality to enhance profitability for our customers. This program will focus on exploiting existing and new collaborations with research and industry partners including new technologies (e.g. Near-infrared Spectroscopy and Dual Energy X-Ray Absorptiometry).
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