Better Pork - April 2007

Letters

Understanding the ‘disconnect’ when it comes to grading

I’d like to clarify some statements made and impressions arising from your article “Can ultrasound grading benefit the pork industry?” (Better Pork, December 2006).

One of the fundamental issues is the “disconnect” between the predicted value of a carcass developed from grading measurements and the actual value to the market.

One measure is the actual yield of fat, muscle and bone found by dissection of a carcass. Processors don’t sell and customers don’t purchase dissected parts. Nevertheless, the yields of these components clearly influence the composition of the products to be produced, the quantity of low-value by-products and the amount of work required to produce them.

Another measure is the value to a buyer of the individual cuts and by-products produced when a processor puts a specific carcass through the cutting, boning and packaging lines. Ultimately, the value of a carcass to the processor is determined by the capability of a carcass to yield value to a customer. Value to a customer, while highly correlated to absolute lean yield, depends on many other factors.

Remember the “disconnect.” By that, I mean the fact that grading measurements are used to formulate “predictions” of the actual yield of a specific carcass. Depending on the accuracy of the prediction, grading methods have more or less value for transmitting the necessary signals of what to produce and what to select for genetically.

I may have been too flippant in the rhetorical question, “Do we care if we grade every pig right?” Yes, we care about measuring the grading parameters correctly for each pig. But, after we have done that, we will still not really know the true lean yield or the economic value for that specific pig with a high degree of precision. It just doesn’t work that way.

As far as ultrasound imaging is concerned, I’ve seen no data to indicate that, in a production situation, there is any better correlation with those results than with optical probes. According to one person in the business of ultrasounding (Tracy Curtain cited in Farmscape Article 2139, May 13, 2006), achieving good results requires considerable training and care in positioning of the transponder when taking measurements. The discussion about grading quality control was well explained by the Ontario Pork Grading Authority official in the Better Pork article and highlights the ease of auditing for optical probe grading.

I think a discussion of this topic is very useful. While it may not be top-of-mind for me right now, we must always strive for better ways to understand value and provide useful signals to those who are in a position to advance its delivery.

Dan Cohoe
Quality Meat Packers Ltd.