Re-read posts #54, #75 & #78, and check out the legal rulings and findings in the links in #54. Your County Extension Agent is incorrect. His advise directly conflicts with a court ruling. As for GAAMPS, you need to review the current rules, but the ruling I partially quoted below includes definitions from the RTFA that protect you regardless of hte number of animals or size of farm (read the whole link--I only included part of it).
It may be that GAAMPS is required by law for larger farming operations such as the 50 units you mention; however that does not mean it cannot be voluntarily followed on smaller operations, which then become protected under the RTFA.
As for forming an LLC, look under your state's Corporation Division:
http://www.michigan.gov/dleg/0,1607,7-154-35299_36737---,00.html
Specifically, from the first link: (bold added to show applicability)
B. Preemption
Defendants argue that if their poultry operation is commercial in nature and in compliance with the relevant GAAMPs, the RTFA preempts plaintiff's ordinance. Plaintiff argues to the contrary that irrespective of the farm's commercial nature or compliance with the GAAMPs, the RTFA is inapplicable because at the time defendants initiated their poultry operation, farming was prohibited on property less than three acres.
State law preempts a municipal ordinance where the ordinance directly conflicts with a state statute or the statute completely occupies the field that the ordinance attempts to regulate. Rental Prop Owners Ass'n of Kent Co v Grand Rapids, 455 Mich 246, 257; 566 NW2d 514 (1997). A direct conflict exists when the ordinance permits what the statute prohibits or the ordinance prohibits what the statute permits. People v Llewellyn, 401 Mich 314, 322 n 4; 257 NW2d 902 (1977).
The RTFA, specifically MCL 286.474(6) provides:
Beginning June 1, 2000, except as otherwise provided in this section, it is the express legislative intent that this act preempt any local ordinance, regulation, or resolution that purports to extend or revise in any manner the provisions of this act or generally accepted agricultural and management practices developed under this act. Except as otherwise provided in this section, a local unit of government shall not enact, maintain, or enforce an ordinance, regulation, or resolution that conflicts in any manner with this act or generally accepted agricultural and management practices developed under this act. [Emphasis added.]
The language of the statute is unambiguous and clearly states that a local ordinance is preempted when it purports to extend or revise the RTFA or GAAMPs. It further plainly states that a local unit of government shall not enforce an ordinance that conflicts in any manner with the RTFA or GAAMPs. It is undisputed that plaintiff's Ordinance No. 212.9 § 9.10(A), which was in force when defendants bought the property in 1995, prohibited raising poultry on a parcel smaller than three acres. It is also undisputed that the property did not exceed 1.074 acres. The relevant GAAMPs provide for the proper management practices for poultry farming, including, but not limited, to facilities, manure management and care of chickens and turkeys. Plaintiff has not produced, and we are unable to find, any GAAMP that limits poultry farming to property consisting of more than three acres. As we concluded above, if defendants' farm is commercial in nature and in compliance with the GAAMPs, it is a farm operation protected by the RTFA. The ordinance conflicts with the RTFA to the extent that it allows plaintiff to preclude a protected farm operation by limiting the size of a farm.
Further, as we previously noted, MCL 286.474(6) expressly provides "a local unit of government shall not . . . enforce an ordinancethat conflicts in any manner with this act . . .". Emphasis added, MCL 286.474(6). We cannot imagine any clearer expression of legislative intent. The plain language of the RTFA precludes enforcement of an ordinance that conflicts with the RTFA.