Milk is an important part of the diet of many people in the west, alongside other dairy products. It has, in recent years been one of the problems: while many people have cut down on eating beef, far fewer has cut down on dairy – but now, if you do not eat beef, you can stop supporting dairy farmers all together.
This is not to say that dairy farmers are bad. Governments need to create different careers and paths for these people to take out of their current work.
A total of 85% of the UK agricultural land is used for livestock raising, and while much of this is for sheep (we are yet to find a way to grow sheep wool in a lab) a great portion of cows are raised for milk. If milk no longer requires a cow, the financial reasons for raising cows will disappear.
Furthermore, 40% of UK agricultural land is used to grow food for animals, so by reducing this requirement, the land needed for farming will reduce even further.
What should be done with this land? Unfortunately with the still rapidly increasing population in the UK (admittedly, the majority of this growth is from immigration not reproduction) some of it is likely to be turned into residential areas. My hope, though, is that a large portion of this land should be reforested with native tree species. The UK forest cover could gradually increase back to nearer to the European average. Alongside this, we could return locally missing species (such as pine martens) or nationally missing species (like lynx) back into their natural habitat