Figure 3.

Effects of vitamin A supplementation on liver retinol concentrations in feedlot steers on days −91, −35, 0, 28, 56, 84, and 112 in relation to treatment initiation (n = 30). Treatments were 0IU, 2,200IU, and 11,000IU. The dotted lines indicate phase 1, a 91-d vitamin A depletion phase prior to treatment allocation or initiation, while the solid lines represent phase 2, where two of the treatments have entered vitamin A repletion. The average liver concentrations were 145.78, 26.33, and 10.35 µg/g for days −91, 0, and 112, respectively.