Control Arm. A control arm is a bar that has a pivot at both ends. Your car has several, including the upper control arm and the lower control arm, which are arranged to form the letter A. Control arms are part of the suspension system.
I think the rule with anything concerning goats is variety and not too much of any one thing. They can eat most veg, but should not get too much at a time, especially of the brocolli and cabbage family, as this can ferment and cause bloat. Goats are greedy and don't tend to stop eating even when they are full, so although they always seem to be ravenously hungry, little and often is better for them. If you milk them, anything they eat can taint the taste of the milk, and I think the cabbage family will do this.
For many people the best, easiest and cheapest way to feed goats is to provide good leafy grass or legume hay free-choice, plus 2-3 pounds a day of a commercial goat feed (grain ration). Others prefer feeding their goats on pasture as much as possible.