Cooperative Extension Publications

By Colt W. Knight, Ph.D., Assistant Extension Professor and State Livestock Specialist, University of Maine Cooperative Extension.

Reviewed by Ashley Wright, MS Area Assistant Livestock Agent, University of Arizona.

For information about UMaine Extension programs and resources, visit extension.umaine.edu.
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How much meat should you expect when butchering your hog or buying pork from local producers? How much freezer space will you need to store your pork? To begin, let’s discuss a few definitions.

Live weight: weight of the animal on the hoof

Shrink: weight animals lose in transportation

Hot carcass weight: Freshly slaughtered carcass with the internal organs and head removed but the hide on often referred to as hanging weight

Dressing percentage = hot carcass weight ÷ live weight x 100

Cold carcass weight: hanging carcass weight after cooling

Cooler shrink: weight lost to evaporation as the carcass cools and ages

Understanding Shrink

Hogs will lose live weight in transportation due to the excretion of manure and urine, but they also lose weight in their bodily tissues due to dehydration. Weight lost to urine and manure excretion is quickly replaced if animals begin to eat and drink normally. Tissue weight loss is much more difficult to replenish, and care should be taken to minimize animal stress, ensure they have access to fresh clean drinking water, and transport during cooler temperatures. In general, we can expect hogs to shrink from 0.69 to 1.95%¹ in transit depending on how far they are traveling and how long they are on the trailer.  Animals withheld from water or transported during hot temperatures would increase the amount of shrink.

Large packing plants utilize spray chilling to increase the rate of cooling and minimize evaporative losses (cooler shrink). These facilities often see less than 1%² cooler shrink. Smaller facilities with more airflow and no spray chilling generally experience 3-5%² cooler shrink.

Understanding Dressing Percentage

There are multiple breeds of pigs raised in Maine to provide table pork. Nationally, most commercial operations utilize pigs that are a cross between Yorkshire and Landrace. These are often referred to as commercial pigs or simply white pigs. They have been genetically selected for lean meat production and large litter sizes. When you buy pork at the grocery store, you are most likely purchasing a commercially bred pig. These breeds are less common in a backyard or pasture-raised production scenarios. Often, small scale producers utilize heritage breed hogs or crosses between heritage and commercial breeds. Heritage breeds are generally referred to as old-world breeds because they are genetically similar to pigs raised 100 years ago. Whereas commercial pigs were selected for lean meat production, most heritage breed hogs were selected for lard production. Therefore, heritage breed animals tend to have less muscle and more fat and are commonly used in charcuterie. Charcuterie is a French word loosely translated as a pork butcher. However, the term is primarily used to describe the fine art of preparing and assembling cured meats and other meat products. The excess fat in heritage carcasses lends itself well to rillettes, mousse, salami, prosciutto, etc.

The average live weight for market hogs is approximately 285 lbs. Commercially raised hogs typically reach market weight in under 6 months. Pasture-raised pigs can take an additional month or two to reach similar sizes. Some heritage breeds may take even longer.  Commercially bred hogs have a dressing percentage of 70-73%³ (including the skin) which yields approximately 55%⁴ in lean meat.  Keep in mind, the skin is approximately 6%⁵ of the pig’s liveweight depending on how much subcutaneous fat is attached. Heritage breed dressing percentages vary from 64-75%⁶. See the table below.

Factors to consider

Heavily muscled hogs will have a 2-3% increase in dressing percentage. Overly fat hogs may have a slightly larger dressing percentage when compared to lean hogs but yield less meat overall. Diet is a major contributor to swine dressing percentages, as well as, quality of the fat, and texture and taste of the meat. Smaller breed like the American Guinea Hog and Herefords typically do not reach 285 lbs. live weight. Skinned hogs will experience more cooler shrink because the skin and subcutaneous fat protects the carcass.

Breed	Typical American Yield	Charcuterie Yield
American Guinea Hog	66%	69%
Gloucestershire Old Spot Hog	71%	71%
Hereford Hog	75%	69%
Large Black Hog	69%	66%
Mulefoot Hog	67%	66%
Red Wattle Hog	65%	64%
Tamworth	75%	73%

Source: University of Kentucky

Pig Yield⁵

Pig carcasses yield 5 primal cuts plus some miscellaneous bits. The ham (18% of liveweight) is comprised of cured ham, fresh ham, trimmings, skin, bone, and fat. The loin (16% of liveweight) is made up of the back ribs, boneless loin, sirloin roast, tenderloin, trimmings, fat, and bone. The side (10% of liveweight) is where we get bacon, spare ribs, trimmings, and fat. The shoulder (8% of liveweight) yields blade steaks, blade roasts/Boston butt, trimmings, and fat. The picnic (8% of liveweight) has boneless picnic meat, skin, fat, and bones.  The remaining 11% of liveweight is made up jowls, feet, tail, neckbones, fat, skin, and bone. This will also account for any shrink or loss during processing.

How much freezer space do you need to store pork?

You will need approximately 1 cubic foot of freezer space for 30 lbs of pork⁷.

Example

References

1.     G. Nasser. 2013. Carcass Shrinkage of Pigs During Transport. Atlantic Swine Research Partnership Inc.

2.     J. Schweifoer. 2011. Carcass Dressing Percentage and Cooler Shrink. MSU Extension. Meat Marketing & Processing. https://www.canr.msu.edu/

3.     G. Rentfrow. How Much Meat to Expect from a Carcass. A Consumer’s Guide to Purchasing
Freezer Meats. University of Kentucky Cooperative Extension Bulletin ASC-179.

4.     Typical Market Pig

5.     Carcass Yield. Meat Technology

6.     B. Perry. 2014. Heritage Hog Carcass Yields. UKnowledge. University of Kentucky.

7.     A. Thiboumery. 2013. Beef and Pork Whole Animal Buying Guide. Small Meat Processors Working Group. Iowa State University Extension and Outreach.

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Information in this publication is provided purely for educational purposes. No responsibility is assumed for any problems associated with the use of products or services mentioned. No endorsement of products or companies is intended, nor is criticism of unnamed products or companies implied.

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