Supplementation of high levels of vitamin D3 (D3) to cattle has enhanced beef tenderness. However, high levels of D3 possess a food safety concern. Therefore, the objective of this thesis was to evaluate feeding strategies that would reduce the amount of D3 required to increase serum calcium (Ca) to levels where tenderness has been improved. In experiment 1, 15 steers (452 ±30kg) were fed with 75% barley grain-base concentrate and 25% barley silage (as fed) and 1.25,2.5 or 5 MIU D3/hd/d for 7 d. Feed intake was depressed (