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Standards of Performance for Livestock Projects: Market Hogs
Livestock Update, April 1998
Mark L. Wahlberg, Animal and Poultry Sciences, Virginia Tech
Background - Trends are for hogs to get bigger and to stay lean. Consequently, loineye area is increasing. Hogs must grow fast and efficiently. Pork quality is receiving greater attention, including such factors as firmness and color of lean and marbling. Genetics that produce problems in this area are being identified and eliminated.
The Standards - Two types of standards are shown below. One is for an acceptable carcass today, and the other is a target to strive to achieve, set by National Pork Producers Council (NPPC) in 1996. Also shown is the target that was set in 1983.
| Standards of Performance for Market Hogs Yesterday and Today | |||
| Item | 1983 Target | Acceptable Ranges | 1996 Target |
| Live Weight | 250 lb | 220 - 270 lb | 260 lb |
| Carcass Weight | 180 lb | 150 - 200 lb | 195 lb |
| Live ADG | at least 1.75 lb | ||
| Age at Marketing | 150 days | less than 180 days | 160 days |
| Lb. Feed / Lb. Gained | 2.5 | less than 3.0 | 2.4 |
| Tenth Rib Backfat | 0.9 inch | less than 1.0 inch | 0.8 inch |
| Loineye Area | 5.8 sq. inches | at least 5.0 sq. inches | 6.5 sq. inches |
| Marbling | not specified | at least Slight | at least Slight |
A sample grid used by a packing company shows the relationship between backfat and weight to value of the carcass. Values shown are percentages, with 100 being 100% of a base price, a value above 100 is a premium price, and one less than 100 is a discount. Backfat taken at the tenth rib is shown in millimeters. One inch equals 25.4 mm, thus 2.5 mm equals 0.1 inch. Therefore, a pig with 0.8 inches of backfat would have 20 mm, and with a 195-pound carcass would receive 104.2% of the base price paid.
A market hog cannot be adequately evaluated without carcass information. Certainly some important traits can be measured in the live animal. However, measurements of backfat depth, loineye area, and product characteristics such as marbling score cannot be done in the live animal without very sophisticated equipment.
The traits mentioned above are expressed as a result of both genetics and environment. Genetics is the biological plan that describes what an animal can be. Environment, which includes feed, health, animal comfort, and other similar factors, must be good enough to allow an animal to express its genetic potential for a trait. As long as the pig is healthy, fed properly, and in a comfortable pen the majority of the differences seen are due to genetics. Therefore, market hogs that hit the target are those with the right genetics that are managed in the right way.