Farm Stock should work just fine for your cow/calf operation. It is designed to keep detailed records on individual animals.
It is designed to maintain birth & weaning weights and when used along with Farm Trac, it will compute weight gains, Days on Feed, Rates of Gain and Feed Conversions. You should also note that this Fall's update of Farm Fund$ will take this information further adding dollars so that you can see the cost per pound gained.
With regards to information on sales, Farm Stock will keep market & carcass weights as well as quality grades, fat thickness, rib-eye area, %K, H, P Fat, USDA Yield Grade, Maturity and Marbling as well as the age of the animal at slaughter. These fields are available for use but are not required.
Additionally, if you want to keep information that Farm Stock is not designed to handle, you can add user defined fields. Additionally, Farm Stock includes a report writer so that you can make up your own reports.