There would be nothing left for them to pick at if they were 100% grass fed. The microbes in the cow's rumen will have broken down the plant fiber and whatever is left will be indigestible.
Mastitis occurs when the teats come into contact with a dirty surface where the bacteria reside. The main thing is to be very clean when dealing with her udder and teats and to keep her living arrangements clean as well. Disinfecting before and after milking is important to keep bacteria...
If the "pasture" is just grass, then I'm assuming there is not much nutritional value. Even though you are supplementing with grain and alfalfa pellets, she still needs more roughage.
Basically going from a free choice hay diet to a restricted diet with less than ideal pasture is not giving...
Just some questions I thought of that might help:
Do you have a specific weight on her?
What is planted in your pasture?
How much pasture space does she have?
Do you know what she was being fed before you bought her?
How does her poop look?
Has she been vaccinated? dewormed?
In addition, bear in mind this: all chemical compounds have what is called a Half-Life, which is the amount of time for half of the compound to decompose. Everything decomposes at some point. I highly doubt the herbicides will last through the compost process all winter and stunt any growth in...
Eventually, yes, you will have to re-breed her. Once a cow has her calf her milk supply will reach a peak productivity point. After that it will slowly taper off. Large dairies will have their cows breed back while they are still milking and dry them off about 2 months before they calve to allow...
I don't have any experience with sheep other than what I've read, but what I can tell you about animal behavior in general is to be persistent. Eventually he should get the hint? Hopefully someone with better experience will chime in!
Ok... I don't mean to be blunt or discouraging, but your first mistake was buying a cow and her calf without any knowledge of cattle beforehand.
But now to the matter at hand. Yes, it would be good to call your vet. He/she can advise you on what to do and whether or not you will need any...