The main difference between grass-fed beef and regular beef comes down to the diet of the cow itself. Grassfed cows, also called grass-finished or pasture-raised cattle, are grass-fed their entire lives and never subjected to finishing on grain in feedlots.
For the first birthday it's worth buying the toddler something "out of the box", and not a rattle that he will get bored with in a while. Check out the best that manufacturers of toys for children have to offer, and choose something unique!