STRATEGIES TO IMPROVE LEAN MEAT YIELD AND THEIR EFFECTS ON PORK QUALITY

Authors: Van Laack, Henriette; Solomon, Morse

Submitted to: Annual Carolina Swine Nutrition Conference
Publication Type: Proceedings
Publication Acceptance Date: 7/7/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: Strategies for altering the balance between lean tissue growth and fat deposition in pigs and the impact of these strategies on meat quality are discussed. The balance between lean and fat deposition can be altered by genetic selection, management practices, growth promoting agents and gene manipulation. In general, there seems to be a genetic antagonism between carcass performance and meat quality. Breeds with a higher lean meat content are often more stress sensitive. This increased stress sensitivity, determined by the halothane gene, results in a higher prevalence of PSE (Pale, Soft, Exudative) meat. Negative effects of the halothane gene may be compensated for by nutrition such as vit. E supplementation. A dominant gene, occurring in Hampshire pure and cross-breds, is associated with reduced cooking yields when producing cooked hams. Both porcine somatotropin (pST) and chromium show promise as an effective tool to improve carcass composition in pigs. Supplementation with these compounds results in an increased muscle percentage and has little or no effect on meat quality. Research on the use of gene manipulation to increase lean meat content is still in its infancy. In transgenic pigs expressing a bovine growth hormone gene, total carcass fat decreased whereas there was no difference in meat quality between transgenic and control pigs. It is concluded that strategies for altering the balance between lean and fat deposition may be enhanced with the incorporation of both the endocrine and nutrition status leading to a superior, acceptable product.

Technical Abstract: Strategies for altering the balance between lean and fat deposition include genetic selection, management practices, growth promoting agents and gene manipulation. A review of the literature indicates that there is a genetic antagonism between carcass performance and meat quality. The prevalence of the recessive halothane gene, associated with increased stress sensitivity, ,is higher in breeds with a higher lean meat content. Stress sensitivity results in a higher prevalence of PSE (Pale, Soft, Exudative) meat. Negative effects of the halothane gene may be compensated for by nutrition such as vit. E supplementation. The dominant RN-gene, occurring in Hampshire pure and cross-breds, results in an increased muscle glycogen content, a low ultimate pH and reduced cooking yields. Both porcine somatotropin (pST) and chromium may prove effective tools for improvement of carcass composition in pigs. Supplementation with these compounds results in increased muscle percentage and has negligible effect on meat quality. Research on the use of gene manipulation to increase lean meat content is still in its infancy. In transgenic pigs expressing a bovine growth hormone gene, total carcass fat decreased whereas there was no difference in meat quality between transgenic and control pigs. It is concluded that strategies for altering the balance between lean and fat deposition may be enhanced with the incorporation of both the endocrine and nutrition status leading to a superior, acceptable product.