Thought I would bump this thread as I finally got up to Northumberland for the 'summer' family holiday - side note 1 : I cannot recommend Northumberland enough as a destination. Lovely and quiet. But don't be expecting wall-to-wall sunshine.
Anyway I had known a bit about the Chillingham cattle since I was very young, and lived half way around the planet, so I was very interested to finally see them. Basically as others have mentioned there is a steep walk through several fields to get to the ranger station (very disease-conscious; no sign of TB in local badgers/livestock currently). You get up to half an hour in the enclosed area on foot with the ranger. Most of the info is the usual stuff trotted out. However what I took out of it:
* They are such small cattle. Reinforces my point that they aren't a remnant Aurochs which were huge, but an early feral cattle. Maybe Roman (given the large presence in the region, it's possible).
* They are all effective clones and inbreeding doesn't seem to be causing any deleterious effect on their health. They drop a single calf each with no problems. Cannot remember how many cattle at Chillingham (80?) but it's not big.
* Scottish sub population is a secret location, to prevent against losing entire herd.
* Nearby castle doesn't have any current links to cattle, but obviously there is quite alot of history together along with paintings and stuffed heads of the cattle. Side note 2 : saw another Chillingham cattle head on the weekend closer to home at Avebury manor!
* Heard the bulls roaring, both while we were in the field and as we were leaving. Eerily, hairs on the back of the neck stuff.
Conclusion - it isn't a zoo, and the visit is for half an hour. But as a piece of natural history evoking a time when the island was cloked in woodland, lovely and cannot be beaten.