Short-term feeding of vitamin D3 improves color but does not change tenderness of pork-loin chops.

The objective of this study was to determine the effect of short-term feeding of vitamin D3 (D3) on blood plasma calcium concentrations and meat quality of pork-loin chops. Three experiments were carried out to meet this objective. Experiment 1 used 250,000 IU and 500,000 IU/d to determine the effective dose of dietary D3 to raise blood plasma calcium concentration. Experiment 2 used 500,000 IU D3/d to determine the appropriate length of feeding time to elevate blood plasma calcium prior to harvest. Experiment 3 used 500,000 IU D3/d to determine the effectiveness of increased blood plasma calcium in improving postmortem quality and tenderness of pork-loin chops. Pigs fed 500,000 IU D3/d in Exp. 1 exhibited higher (P < 0.05) and more stable plasma calcium concentration over a 14-d feeding trial compared with pigs fed 250,000 IU D3/d and control pigs. Therefore, 500,000 IU D3/d was the dose chosen for Exp. 2, in which pigs fed 500,000 IU D3/d for 3 d prior to harvest exhibited elevated and stable plasma calcium concentrations; this length of time was deemed sufficient in which to observe differences in postmortem meat tenderness in Exp. 3. Vitamin D3 supplementation resulted in lower (P < 0.02) L* values and higher (P < 0.03) a* values of loin chops at 7 and 14 d of shelf storage. Vitamin D3 supplementation did not affect quality characteristics (measured by use of subjective scores) or tenderness (quantified via Warner-Bratzler shear force or Star probe values). On the basis of these findings, feeding 500,000 IU D3/d to finishing pigs improved most Hunter color values at 14 d of storage but did not improve pork-loin chop tenderness at 1 to 21 d of retail shelf storage.