Effect of implant and intake level on phosphorylated extracellular signal-related kinases (phosphor-ERK). Myocytes from a non-study steer were treated with serum (20% of total media) from study steers drawn on d 0 and 28, and phospho-ERK abundance was measured. Steers were (Chart A) either implanted (gray bars) or not implanted (white bars) with a long-acting TBA:E2 implant and (Chart B) fed a common diet at either 2.0 (gray bars; HIGH) or 1.0 × (white bars; LOW) maintenance NE requirements. (Effect of intake P = 0.65; implant P = 0.47; intake × implant P = 0.41). Pooled SE for treatment means was 0.065.