Hi VF, since I'm just learning all these new words myself, maybe I can help!
FEC is a Fecal Egg Count (Darn - cross posted with Rosemary!). Basically you take bits of poo from several different sheep down to the vet, who charges you £20 to look at it under a microscope to tell you how many worm eggs are in it. The vet will then advise what action to take if any. The reason you put them in a barn is so that the infected poo that they do whilst you're waiting for the test result and wormer to take effect can be cleaned up and doesn't infect clean pasture.
The other thing to ask about is whether they've had any vaccinations. Heptavac-P is the one most commonly used and gives protection against a variety of chlostridial diseases. If they're on a Hep-P programme, they should have had two doses as lambs, and will then need an annual booster in the spring.
Others may disagree, but if I only wanted some sheep to mow the lawn, I'd be looking for something more interesting than Texel crosses! You could go for something really friendly and nice to look at, like Ryelands or
Zwartbles (had to get the Z-word in somewhere!
) , or you could support a
rare breed, or even get a mixture of different rare breeds.
The 'how many sheep can my land support' question is a nightmare for beginners. I've had estimates of between four and forty for our five acre holding depending on who I speak to. Really it seems to depend on so many factors that it's hard for anybody to really say. The best advice seems to be to start with just a few so you can be sure you're not over-stocking, as you can always get more later once you've got a feel for it.
Hope that helps!