[landroverroy]

Well it's funny you should say that. Like I said, the pecking order is very strong, so it seems to depend if you had an animal that was dominant or subserviant  when with its highland herd.
I have mixed highlands with my hereford cattle and the dominant ones march to the food with an air of supreme confidence, expecting the herefords to stand back, in the same way that inferior (to her) highlands would. However the herefords all work on the theory that she who hesitates is last (and goes hungry), so they dive in and attempt to push the highland out of the way, totally oblivious to her horns.  So if the highland holds her own, then she's fine and won't get bullied, but it's really funny when she realises that the herefords don't give a toss where she was in the pecking order. So a fairly dominant highland will cope ok because she won't let herself be bullied.
On the other hand, a few months ago I had to bring an 18 month old highland heifer inside to treat her warts. The only other bovine I had inside was Tina, an 8 month old hereford calf that had recently lost her mother. Tina had been inside for a while and regarded the pen as her territory. But she was considerably smaller than Hermione and didn't have horns. So I was very surprised that Tina quickly established that she  was the boss. Presumably Hermione, being a young cow, will have been fairly near the bottom of the pecking order with her highland herd and so will have shown some subordinate behaviour to Tina who instantly picked up on it. It was really funny watching the calf push the bigger, horned animal about the pen. She wasn't nasty to her, to the extent of chasing or bullying her - just pushed her out of the way if say Hermione was feeding from her food trough. I now have the 2 of them outside, and Tina still pushes Hermione about if she gets in her way, but it's quite casual and certainly not bullying.. 
Sophie, the one I mentioned above, was always bottom of the pecking order with the highlands, and I think it's just because some animals just act as if they expect to be bullied, and it becomes a self fulfilling prophecy. Anyway, at the moment she's with the herefords because she has fantastic hereford x calves, so it seeems a waste to put her  to a highland. You can tell by her body language that she is not a dominant animal, and she does hang back a bit. But we have plenty of feed rings and the herefords are not a bullying breed so she gets on fine with them.   
So, in answer to your question, yes a highland would cope alright with a different breed of cattle.  A dominant one  would probably fit in better, but a lower pecking order one would be treated as inferior whatever it was with, so would always seem to be on the outside.

[shygirl]

thanks, that's really interesting. 

[Rosemary]

It is interesting. I read somewhere that a cow's position in the hierarchy was determined by her mother's so I wonde if dominant / subservient behaviour is learned.

We have two 2010 born cows; Blizzard is younger than Breeze by 2 weeks and seemed to be subordinate until they were pregnant then she bacame the boss. We now have Blizzard, her 2012 daughter Annie and Annie's 2014 heifer calf plus Breeze, her 2013 daughter Bonnie and her 2014 daughter Sunny.

All of Blizzard's line even the calf eat first, while Breeze and her family wait. Breeze will push Annie around but only if Blizzard is otherwise occupied. I wish I had more time to sit and observe them - the behaviour is much less obvious when they are outside.

[SallyintNorth]

According to Val Porter, it's not a hierarchy per se with cattle.  Each beast has its own relationship with every other beast.  So while A may boss B, and B may boss C, it's not a given that A can boss C.

We certainly observe that there's usually a 'top cow', who commands respect from everyone.  Some of them wear their stripes with dignity, others abuse their power.  For instance, some 'boss cows' will keep everyone else away from feed, even when there is plenty for everyone.  (Most just make sure that they are eating the best bit, but don't mind others feeding on other parts.)  'Bully cows', the ones who seem to abuse others for the heck of it, don't get to stay in the nice warm shed over winter...

And there is often a 'bottom cow', who everyone bosses.  Our cubicle shed has two sections, a smaller one for my Jerseys and any heifers, and the larger one with bigger cubicles.  On a few occasions we've moved the bottom cow up from the large section to the Jersey section, and in every case she has then proceeded to bully my Jerseys and been moved back again! 

Hillie (my foundation Jersey) is boss of all the Jerseys, and is herd spokescow.  When they are all outside, she often makes decisions for the herd, even though she isn't top cow.  I think they recognise her intelligence and respect her decision-making.  They certainly know she can get us to do things they need!  If Hillie is out of the picture, Plenty (her firstborn) takes over the Jerseys at the moment, but I can see that changing in time; Katy (Plenty's little sister, just rearing her first calf at the moment) has a lot more about her, I think, and I predict her becoming No 2 when she realises that!  The other (non-Jersey) cattle take no notice of any of the Jerseys apart from Hillie.