What is the fine-grained topic of the following text: The ranch, established by Christopher Bently in 1997, produces grains as well as Angus, Hereford, and Charolais-blend cattle — humanely raised, grass fed, grass finished, hormone free, and Global Animal Partnership (or GAP) Step 4 certified — on more than 50,000 acres in Northern Nevada and California. Only return the topic.
Sustainable cattle and grain farming at Christopher Bently's ranch