Good work on figuring out a use for quack grass.

Most animals just don't like cogon grass, unfortunately.

UF states:

"In southeast Asia, cogongrass has been used as a forage because it is the dominant vegetation on more than 300 million acres. In these areas, it was found that only very young shoots–which lack the sharp points and razor-like leaf margins–should be grazed or cut for hay.

Cogongrass yields are relatively low–even under heavy fertilization–and usually do not exceed five tons per acre. The plants rarely attain the minimal level of crude protein (7%) needed to sustain cattle. Furthermore, the nitrogen, phosphorus, and energy content of cogongrass are very low, requiring supplementation for livestock."

http://solutionsforyourlife.ufl.edu/hot_topics/environment/cogongrass.html