Your steer being a dairy breed will mean that he won't be genetically inclined to be a really heavy muscled animal. Depending on the quality of the grain and the percent protein, will also influence the weight gain. If you want your steer to be a fast growing, heavy carcased animal at slaughter, try getting a beef or beef cross steer. You'll have to figure out how much grain you'll be feeding him though. I know people that only feed their steers 1-2 lbs a day and others that feed on the upwards of 16 lbs a day. You'll just have to test and see. Good Luck