Article for Ontario Pork News and Views
November/December, 1997

Sourcing Genetics: Breeds vs Breeders

J.P. Gibson
Centre for Genetic Improvement of Livestock
Animal & Poultry Science
University of Guelph

A pig production system can only be as good as the pigs that are in it. If you don't have the right genetics in your herd, you will be working hard as a manager to overcome the poor genetics of your pigs and, no matter how hard you work, the quality of your product and your profitability will never be as good as it should be. But, until recently, we had little idea of how good was good; and whether or not it really makes that much difference which breeding stock you use in your herd. One of the results of the recent Ontario Pork Carcass Appraisal Project (OPCAP) was a comparison of the differences between breeds and the differences between different breeding stocks within each breed, for a range of growth, carcass and meat quality traits.

Traditionally, one tends to think of breeds first and then worry about breeding stock second. However, the OPCAP results showed that there was 50% more variation in growth rate between breeding stocks from different breeders than there was between the breeds themselves. For backfat, there was 3 1/2 times more variation between breeding stocks than there was between the breeds. This means that it is actually more important to find the right source of breeding stock than it is to get the right breed for your system; although obviously both are still important. When it comes to carcass lean content, there was 2 to 3 times more variation between different breeding stocks than there was between the breeds. But, when it came to the distribution of lean meat, ie. how much meat was in the ham vs. how much meat was in the loin, for example, there was considerably more variation between breeds than there was between breeding stocks. When it came to measurements of meat quality such as drip loss, marbling score, color of the meat, structure of the meat, there was also considerably more variation between breeds than between breeding stocks. These objective measures, coupled with taste panel results coming from the Lacombe Research Institute, indicate that the Hampshire breed continues to give the best eating quality followed by the Duroc with the Large White and Landrace lagging considerably behind.

So, when it comes to choosing breeding stock to fit your operation, if you are interested in shape of the carcass or meat quality, go shopping for the right breed first and worry about from whom you should get that breed secondarily. But when it comes to all the other production and carcass traits, it is critical that you find the right supplier of breeding stock. Unfortunately, there is not a great deal of good information on which to judge many of the important aspects of pig profitability, particularly the carcass quality traits. Many of the trials of different breeding stock by several of the packing plants, for example, had different breeding stocks coming from different production herds. As such, this is more a test of management ability of different herd managers than it is of true genetic merit between different stocks. The only fair comparison is to have different genetic stocks tested in the same production environment under the same manager. Only a small amount of such data exists at the moment, although several trials are underway to expand the amount of such information, both here and in Quebec. Larger producers could even do their own controlled trial of different sources of breeding stock. For example, if you have 1,000 sows, you could breed 1/4 of your herd to each of 4 different sire lines. Test at least 10 sires from each sire line and record detailed information on all of their progeny, including carcass probe and indexing information from the packer. At the end of the year, you should have sufficient data to make reasonably accurate comparisons among these 4 lines. These can then be converted into profitability within your system. The current EBV system allows you to make a first choice of sire lines by picking those sire lines which rank highly on the combination of EBV for growth rate and backfat as best suits your requirements. We have estimated that the difference between the top 10% vs the bottom 10% of breeding stock is probably in the region of about $10 extra profit per pig marketed. So, it is well worthwhile making sure you make the right decisions about which breeding stock are in your production herd.