it coud be differnet in different areas though 
No it can't -it is basically the same regulation in Engalnd, Wales and Scotland (and probably NI, but haven't delved into that yet)

- However many Trading standards and animal health officers mis-quote, mis-understand and confuse holding no. with herd no. Can't blame them, with rules on cattle, sheep, goats and pigs changing every couple of years since F&M, I doubt anyone can spout all the regs. Last time I counted there were around 20 regulations on livestock, and 40 or more covering the farming industry that we are all s'posed to know.
For instance at an HSE course I did the other day, we were told that if you have an income from your smallholding, then you are a business for H&S law, and so should have class 1 or 2 ladders which are labelled as such (class 3 - domestic is not allowed), and should inspect these once a year, and note any defects in your inspection record book. Hands up who does this??? and hands up who has ladder inspection report book?? Thought so!
PS before you all start looking at ladders, this is only what we were told. I like to look for the actual regs, rather than what an official tells me, as the posts above show - it is not always right !