Thanks to Farm Policy, here's the final rule on nondiscrimination at USDA--from the preamble:
" Applicants and program participants will provide the race, ethnicity, and gender data on a voluntary basis."
If I read it correctly, it makes the rules currently applicable to the service center agencies (FSA, NRCS, and RD) apply also to other USDA programs which directly serve people. That's important, because most of USDA's money is indirect--the food stamp, WIC, etc. program administered through state agencies. It also expands the protected grounds to political beliefs and gender identity.