My lot  love readigrass = its their favourite of all the chaffs etc.  I am always very careful, even if I have to change goat mix, if the shop has not got my usual sort.  I mix it with the usual feed until they are used to it.  Again, going into winter, I feed sugar beet, and introduce it gradually to the females.  I am a great believer in fibre, and bulk feeding, and always feed hay, even in summer  (although we have struggled for good hay this year as it was so wet last winter).