As noted by other posters... even a large fowl cock may only be a sacrifice instead of your hen and no TRUE protection.
My boys call warning calls all the time. The hens rarely listen because of so many times crying wolf.
No, most roosters WON'T fight to the death with others. Each is an individual. I keep a stag pen. Have had up to 14 cockerels in there, though now one rooster and 4 cockerels. They get along for the most part with some scuffles. But most know their place in the order of things. My head rooster a Marans (known fighting breed) allows new boys into the pen. And even breaks up fights sometimes. That's why he is still here. He has only looked at me cross eyed once, where i gave him a little chase and no issues.
My first "rooster" experience though, I was so thrilled with the handsome fellow who wanted to hang out on my lap! Until hormones kicked in and he tried to grab a hen off of my lap. Then one day I felt something brush the back of leg. And turned around to see him standing there all innocent like and thought I must be hallucinating. Then another day I felt something brush the back of my leg, but I'm no fool and gave him a little chase. It got to where he would attack when my back was turned, charge me at the fence, and stock me but pretend to do busy work when I looked his way. It continued for a while because this was my Swedish Flower breeder boy of choice. I was after all ALMOST in love with him. I am not afraid of roosters (or dogs) and in no way did I present myself as weaker. After months of him crowing AT ME obsessively when he saw me, I had enough.

I thought we were building trust early on that he would know I wouldn't harm him and that I wasn't a threat. It kind of worked out that way, as he certainly was not afraid of me. Off to freezer camp he went and I swear that was the best Ditto noodle soup I ever had. The saying "the meaner the roo the sweeter the stew" totally held true for me. My only regret was not doing it sooner. I almost couldn't stand to hear my other boys crow without taking it personal for a good month or so afterwards, which is part of the joy of owning boys. I never coddled another boy and never had that problem again YET. I'm happy to say that I am indeed back to enjoying my boys. And the really good ones that dance for the ladies and call them to treats plus take no for answer sometimes are especially handsome and favored.
But one factor is... what age are you calling a rooster? Their protective hormones don't kick in until a certain age.
How old are your ladies? And how do you know it was your cat? I never consider cats a threat to full sized hens, but chicks is a different story. Just because it isn't common though doesn't mean it isn't possible.
Glad you didn't lose any birds!
On roost when I go in for treatments or whatever, the boys very often try to duck and hide. It's dark and they don't know it's me. I could be any predator, it didn't matter they are cowards, also known as CHICKEN. Besides a rooster will never be a match for most of the predators we have here, even IF they try. But they would get credit for trying and I have seen some who have successfully fought of predators for others. My boys are kept for breeding, not protection.. since as noted many aren't good at it anyways.
Hope he still becomes a nice bird for you and your flock.
