Intricacies of Carcase and Meat Quality09 April 2015
Raising pigs is all about feeding a rapidly growing human population and profitability, writes Dr Nick Boddicker from Canadian pig genetics company Genesus.
It is easy to identify the key components to a successful and profitable operation: sow productivity, growth rate, feed conversion, back fat depth, and death loss.
However, there is an underlying component to profitability that is often overlooked, and that is carcass and meat quality.
I often hear producers say “well I don’t get paid for meat quality” and in the direct sense, that is true. However, meat quality is the foundation of the swine industry.
Without meat quality, people would not buy pork and the industry would be dramatically changed.
Carcase traits include hot carcass weight, dressing percentage, lean yield, fat depth and primal yield.
Some of the key meat quality traits include shear force (a measure of tenderness), marbling, colour, pH, and drip loss. Many of these traits are correlated with each other, and some of these associations are antagonistic, i.e. by moving one trait in a favourable direction, another trait tends to move in an unfavourable direction.
Some examples of unfavourably related traits are back fat with growth and intramuscular fat (IMF).
Back fat is genetically positively correlated with both growth and IMF.
Therefore, the higher the growth rate and the higher the IMF values, the more backfat a pig will likely have.
Two more examples of unfavourably correlated traits are loin muscle area (LMA) with shear force, and LMA with IMF.
Shear force and LMA are positively correlated; LMA and IMF are negatively correlated
Not all carcass and meat quality traits are unfavourably correlated. Back fat and LMA are negatively correlated, which is favourable. As back fat decreases, LMA increases.
Also, in terms of meat quality, back fat and tenderness are positively and favourably correlated, although some may view that as an unfavourable correlation. Intramuscular fat and tenderness are positively and favourable correlated as well.
These genetic correlations reported above (outlined in Table 1) are inherent and are likely present for some physiological reason.
Therefore, the unfavourable correlations are difficult, if not impossible, to work with in a selection programme.
On top of the genetics are environmental factors than can have effects on carcase and meat quality.
This includes diet, killing method at the plant, stress, etc. Stress in particular can cause PSE (pale, soft, and exudative) pork.
The above has demonstrated the difficulty of producing a fast growing, high lean yield pig with high IMF, tender and tasty meat; however, effective selection programmes can produce pigs with the desirable characteristics.
Since 1998, Genesus has been dedicated to carcase and meat quality recording, with over 14,500 Duroc pigs with extensive carcase and meat quality data by the end of 2014.
The Duroc breed is known for its superior growth along with carcase and meat quality traits.
The Genesus Duroc is our only sire line and, with our large (more than 1,000 sows) population, we have successfully achieved a superior terminal Duroc line that is fast growing and efficient with excellent carcase and meat quality characteristics.
However, we strive to continuously improve these traits through extensive data collection and research and development. For example we are just completing a large-¬?scale project focusing on development of genomic selection methods for carcase and meat quality traits. Incorporation of these tools will drive even more effective genetic improvement in the Genesus Duroc. Additionally, we continuously test young sires for the stress gene, which was eliminated from our populations long ago.
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