The umbelifer looks like hogweed, but there could be cow parsley in there. Both fine.
The pink stuff at the back looks from the pic like foxglove, which you don't want as it's a poison - very pretty though. Foxglove is the plant from which Digoxin, a heart medication, which slows the heart right down and can stop it, in humans is derived. Sheep tend not to eat it, but I wouldn't trust that and would dig it out, leaves as well as flowers. Sometimes when toxic plants are dried as hay they either become more toxic, or more palateable to the animal so it will eat it in hay, when they wouldn't touch it fresh.
Stand back and look at what's growing in your field. You will see that the grass has a variety of seed heads, different shapes and colours, and heights. That means the grasses are of mixed types - there are a large number of grasses, and it doesn't really matter what they're called, just which are nutritious and which are not. When pasture is part of a rotation, where different crops are grown in each field in a set order, with soil nutrition in mind, the seed is carefully chosen for variety. I only keep primitive sheep, so I don't want the commercial type of grass, as it's too rich for my sheep. Our pasture has become 'permanent pasture', where it's not part of a crop rotation, and is not reseeded every few years, so different species of grasses, wild flowers and weeds grow.
For weeds, the persistent ones are ragwort (toxic, get it out, root and all and burn it), thistles, burrs, sticky willie (cleavers), and nettles if you don't want them, but some sheep eat them, and certain butterflies need them for their survival. You also don't want brambles, foxglove as mentioned, rushes, although they're not toxic, just a pest. there will be more depending on where you live, and certain garden plants hanging over the fence will be highly toxic too.