Summary and Implications
The variation in backfat of commodity pork has declined to the point some major packers are no longer measuring backfat depth. From our previous research with Berkshire pigs, a large amount of variation in backfat and loin eye area (LEA) still existed, especially between barrows and gilts. In our previous research, barrows average one inch backfat depth around 210 pounds whereas gilts did not achieve one inch until 260 pounds. This potentially may be a meat quality issue for gilts marketed less than 260 pounds.
The objective of these trials was to replicate our previous study and to determine whether these differences persisted within a different set of Berkshire pigs under the same nutritional regimen. Understanding how feed programs and growth rates affect lean and fat deposition rates is a critical aspect to these niche programs in order to maintain consistency and quality of the Berkshire pork products marketed. Overall, barrows averaged an inch of backfat between 230 and 250 lb body weight whereas gilts average backfat was .90 inches at 269 pounds market weight. Only a 30% of the gilts within these two groups were over one inch backfat at market. These differences are crucial when selecting animals for market to achieve the highest desirability in meat quality within the Berkshire marketing system. These differences between barrows and gilts indicate it may be more critical that each are fed differently than in commodity pork production systems.
Iowa State University
Swantek, P. Matthew; Roush, Wayne B.; Stender, David R.; Mabry, John W.; and Honeyman, Mark S.
"Backfat Depth and Loin Eye Area Measurements of Purebred Berkshire Pigs Housed in Hoop Buildings in Iowa,"
Animal Industry Report:
AS 660, ASL R2936.
Available at: http://lib.dr.iastate.edu/ans_air/vol660/iss1/101