Fig 4. Feed intake and feeding rate from each trough.

Means ± SEM are shown for intake of (A) Sudan grass hay from the gated trough and (B) the primary diet treatments from the open trough, (C) back-transformed means and 95% confidence intervals for the feeding rate from the gated trough, and (D) means ± SEM for the feeding rate from the open trough. All heifers were fed 200 g/d of Sudan grass hay behind a gate that must be pushed to gain access, and to which additional weight was added daily until cattle no longer used it. In the unrestricted open trough, heifers had free access to either a total mixed ration with 12% forage (as fed, low roughage, n = 6) or 100% Sudan grass hay (high roughage, n = 6). To allow for consistent comparisons among heifers, behavior was evaluated on 5 d (relative to the day they pushed the maximum weight), and data are presented across days. Day was included in the model as a continuous variable but was summarized as categorical for graphing purposes.