How you treat the purchase of cattle and other livestock depends on how you will use the livestock on your farm. If the cattle were purchased with the intention of selling to others then the purchase is reported under Inventory. For example if you purchase a calf with the intention of selling it at maturity, the calf would be considered inventory. If the cattle were purchase for draft, breeding, or dairy purposes you have the choice of treating the cattle as an asset or inventory.
You do not get a deduction for the purchase of cattle in the year of purchase unless you purchase and sell the cattle in the same year. Instead you report the purchase cost during the year you sell the cattle. If you are a cash basis farm this is reported in TurboTax under Farm Income section under Livestock, grain, produce, customer work, co-ops". If you are an accrual basis farm this is reported under the Farm Income section under "Cost of goods sold". If you did not sell any of the cattle this year then keep records of your purchase costs for when you do sell the cattle. You may also use the Unit-livestock-price-method. I will include a link later about his.
If the cattle are for draft, breeding, or dairy purposes and you did not include them in inventory then you can depreciate them as assets. This is done in Turbo Tax under the Farm Assets section. Depreciating the cattle allows you to deduct a portion of their purchase cost each year.
Just a few other thoughts. While you cannot deduct the purchase of cattle for inventory during the current year you can deduct the feed, vet expenses, and other ordinary farm expenses needed to maintain and raise the cattle. This is also true of cattle reported as assets. The cost of raising the cattle is considered ordinary operating expenses and is deductible in the year paid as farm expenses.
Cattle that are born to your stock are usually treated as inventory because you do not have a cost basis in these cattle. You cannot depreciate them since you will not have a purchase price for the cattle. Again your feed, medical expenses, etc are deductible as current operating expenses.
Finally, the link I promised. The Unit-livestock-price-method is discussed on page 7. This publication also includes a lot of information the tax treatment of a farm. If you are new to farming I would suggest spending some time with this publication.