In a paper of this kind it would be very easy to be over ambitious and therefore be tempted to go too far in an effort to establish relationships between the physical and the other factors which have influenced the livestock policy of this region. Apart from the complexities of these relationships which make it difficult to determine their influence, there is generally a large gap in our knowledge of the physical data relating to livestock farming. For example it is only fairly recently that we have come to realise the subtle influence that certain “trace elements” have on the health of ruminant livestock, and also the marked differences that exist in the feeding value of grass of varied species according to the type of farming practised.