Vitamin D-biofortified beef: A comparison of cholecalciferol with synthetic versus UVB-mushroom-derived ergosterol as feed source.

This study investigates dietary fortification of heifer feeds with cholecalciferol and ergocalciferol sources and effects on beef total vitamin D activity, vitamer, respective 25-hydroxymetabolite contents, and meat quality. Thirty heifers were allocated to one of three dietary treatments [(1) basal diet + 4000 IU of vitamin D (Vit D); (2) basal diet + 4000 IU of vitamin D (Vit D); and (3) basal diet + 4000 IU of vitamin D-enriched mushrooms (Mushroom D)] for a 30 day pre-slaughter period. Supplementation of heifer diets with Vit D yielded higher (p < 0.001) Longissimus thoracis (LT) total vitamin D activity (by 38-56%; p < 0.05) and serum 25-OH-D concentration (by 20-36%; p < 0.05), compared to that from Vit D and Mushroom D supplemented animals. Irrespective of vitamin D source, carcass characteristics, sensory and meat quality parameter were unaffected (p > 0.05) by the dietary treatments. In conclusion, vitamin D biofortification of cattle diets is the most efficacious way to enhance total beef vitamin D activity.