The work presented in this bulletin is the result of the cooperative feeding experiments conducted on the Brookmont Farms, property of A. E. Cook, Odebolt, Iowa, under the supervision of the Animal Husbandry Section of the Iowa Experiment Station. Three distinct lines of investigation were conducted: the first being a test to determine the relative economy of feeding light, medium, and heavy grain rations in beef production. The second was a test to determine the comparative value of Western and Northern steers in comparison with those from the Southern states for feeding purposes under Iowa conditions. The third was a continuation of the work commenced in 1902, reported in Bulletin 66 of this station relating to the feeding value of the va...