Feeding Vitamin D₃

Tenderness is one of the most critical attributes in determining consumer satisfaction with pork. Modern consumers demand pork that is not only lean but also tender. Unfortunately, fast lean growth genetics and meat tenderness are not necessarily positively correlated. After many years of selection for higher lean growth genetics, the incidences of tough pork products has been increasing. The challenge for the pork industry is to produce leaner pork without sacrificing tenderness.

The connection between calcium and meat tenderness has been well defined through research. Postmortem tenderization of meat products is the result of the activities of a family of calcium-dependent enzymes present in the muscle, known as calpains. The activity of calpains, which are controlled by the calcium concentration in the muscle cause the breakdown of muscle fibers resulting in more tender meat.

Vitamin D₃ increases the amount of free calcium transported across the intestinal wall, which results in increased levels of free calcium in the bloodstream and muscle. The efficacy of feeding a high dosage of Vitamin D₃ to increase postmortem muscle calcium and improve meat tenderness has been investigated in beef and lamb. Results demonstrated an improved tenderness in beef, but not in lamb.

Researchers at the University of Illinois and Iowa State University recently conducted studies to investigate whether feeding high levels of Vitamin D₃ to pigs before slaughter improves pork tenderness. They found that feeding high dosages of Vitamin D₃ to pigs for several days prior to slaughter might result in dark colored pork, which might be of higher value to Asian consumers. However, results from both studies failed to show positive effects on pork tenderness. Table 1 is a summary of the two studies.

Table 1. Summary of two studies investigating the effects of feeding high levels of Vitamin D₃ prior to slaughter on pork tenderness and other pork quality traits

Results:

Illinois Study

• No tenderness improvement
• Improved color and firmness scores in loin chops and reduced drip loss
• Reduced feed intake and growth performance

Iowa Study

• No tenderness improvement
• Improved color
• No detrimental effects on feed intake or other performance parameters

References:

Wiegand B. R. et al. 2002. Short-term feeding of Vitamin D₃ improves color but does not change tenderness of pork-loin chops.

J. Anim. Sci. 80:2116-2121.

Enright Kendra, et al. 1998. The influence of level of dietary Vitamin D₃ supplementation and post-mortem aging time on pork quality.

Swanek S. S. et al. 1997. Effects of supplemental Vitamin D₃ on meat tenderness.