We don't know. But if you sell at a gain, you'll pay taxes on the gain.
As I understand it, the basis for the cattle would be stepped up to the value of the cattle on the date of death of your mom. So the gain would be the difference between the value on the date of death and what you sell them for less any sales commission. A gain on the sale of inherited property is always long term.
The forum has SuperUser Cattlerancher interested in ranching, farms, and livestock, but I haven't seen him around in a while. If he sees this he might have some additional perspective to add. @Cattlerancher
Texas Roger has it correct with one exception.
Date of death stepped up cost basis applies to breeding stock and calves, the sale of cows and bulls (breeding stock) are reported on form 4797, part 1 (Long term capital gain, business property using DofD cost basis).
The sale of calves would be reported on schedule F as earned income, on line 1a,b,and c (calves purchased for resale) using DofD cost basis as your cost on 1b. This is assuming they are continuing the farm business themselves and will sell the calves at a later date than DofD.