a good ration is based on the amount of milk taken. If you can milk around 3 liters you would have to feed accordingly. If you feed for 3liters but take 1, you will give the herd a diet way too rich, they will fatten and get sick. And perhaps stop making milk. This is the difference between dairy and wool or meat. Taste in the milk could come from using onions or cabbage for feed. Corn silage will change the taste of milk as well. Thats in gerneral for all milk. Grass taste changes with location; species variety, rain, soil acidity, etc, so milk is afected by that as well. Example; feed your animals garlic for a couple days, and your milk will become garlicky tasting. Not great for developing yeasts nor bacteria. Or milkshakes.
the rundown: correctly feeding is very complex, try 500g per day in equal portions to begin, but not all at once, progressively.