Superior Farms is a farming cooperative whose ranchers have been producing acclaimed lamb products since 1963. They have been in the forefront of the farm-to-table movement in Northern California. Superior Farms Pet Provisions produces their natural lamb and venison pet treats and chews from its own facilities in USA and New Zealand. Their treats are preservative-free and undergo irradiation to eliminate the potential for foodborne pathogens. See this paper for a discussion of this process.