Use of 25-hydroxyvitamin D₃ and vitamin E to improve tenderness of beef from the longissimus dorsi of heifers

¹ Department of Animal Science, Iowa State University, Ames, IA 50011
² Department of Animal Science, South Dakota State University, Brookings, SD 57007
³ National Animal Disease Center USDA/ARS, Ames, IA 50010

^* To whom correspondence should be addressed. E-mail: dcbeitz{at}iastate.edu.

	Abstract

The objective of this trial was to determine whether a single bolus of 25-hydroxyvitamin D₃ (25-OH D₃), vitamin E, or a combination of the 2 would improve the tenderness of steaks from the LM of beef heifers. Forty-eight Angus crossbred heifers were allotted randomly to 8 pens. Six heifers were in each pen, and there were 2 pens per treatment. The 4 treatments included Control, no 25-OH D₃ or vitamin E; 25-OH D₃, 500 mg of 25-OH D₃ administered as a one-time oral bolus 7 d before harvest; Vitamin E, 1000 IU of vitamin E administered daily as a top-dress for 104 d before harvest; or Combination, 500 mg of 25-OH D₃ administered as a one-time oral bolus 7 d before harvest and 1000 IU of vitamin E administered daily as a top-dress for 104 d before harvest. Blood samples were obtained on the day that heifers were allotted to treatments, on the day 25-OH D₃ was administered, and on the day before harvest. Plasma calcium concentration was increased when 25-OH D₃ was administered with or without vitamin E (P < 0.007). In LM, calcium concentration tended to increase (P = 0.10) when 25-OH D₃ was administered alone but not when 25-OH D₃ was administered with vitamin E. Concentrations of 25-OH D₃ and 1,25-dihydroxyvitamin D₃ in plasma were increased when 25-OH D3 was administered with or without vitamin E (P < 0.001). Steaks from heifers treated with 25-OH D₃ or vitamin E, but not both, tended to have lower Warner-Bratzler shear force than steaks in the control group at 14 d postmortem (P = 0.08). Postmortem protein degradation as measured by western blot of the 30-kDa degradation product of troponin-T was increased with all treatments after 3 d postmortem (P 0.07), but not at 7 or 14 d postmortem. Unexpectedly, use of 500 mg of 25-OH D₃ fed as an oral bolus 7 d before harvest or 1000 IU of vitamin E administered daily for 104 d before harvest alone but not in combination effectively decreased Warner-Bratzler shear force.

Key Words: beef, 25-hydroxyvitamin D₃ , tenderness, Vitamin E