Hi TecCowGirl and welcome to the forum.
For your cattle situation there are vests made for rodeo riders at around $120.00 or higher. They are made for your purpose, but they will not stop knives or bullets.
Cheaper for you and easier to find is some hockey goaltender upper body gear. You can find it from kid sizes to extra extra large adult, often used and cheap at many sports stores and arenas. But again it won't stop bullets or very sharp objects.

At KIngs Coat in Red Deer and several other surplus stores there are old flack vests for a low price and actual armour carriers to choose from.

If you need something for the cattle maybe check out the first suggestions and if you desire bullet stopping potential seek the right stuff.

I grew up around cattle and have also been crunched. Winded terribly and some cracked ribs I think only a steel cage around the body would have worked but i was rammed against the fence and barn. Just getting knocked around I think the rodeo vest or goalie armour would have been very helpful.
I also play goal and have served in the CF and know that the right gear for the job makes you happy when it's there.