Wildlife Management under Texas Parks and Wildlife is a sub-part (1-d-1) of Ag 1-d. You are still Ag and have the same tax break (I paid $162 in tax last year for 200+ acres) and you give up nothing. Wildlife Management can not go away - it has been protected by a constitutional amendment (Ag is a constitutional amendment as well). It will not go away and is not a "govt. program" that will dry up at the whim of a yahoo in the next budget cycle.
It is simply an acknowledged, by the State of Texas, way for a land owner to put back into the land instead of pulling out of the land and still get the same tax credit for working hard on the land to benifit the whole state (farming, ranching, or, increasing the quality of wildlife that will spread to surrounding area and increase the health of the overall populations without running cattle, goats -heaven forbid- or, llamas).
You can still have Bessie, but this gives you another option and credit for what you are probably doing anyway. Now you can eliminate some overhead if you wish. See the link above and it will give the particulars.