We have 21 cows that are 8 or older out of 91. And, this is after culling over 70 head this year. Of those 21, one has probably the poorest conformation of any cow that we have ever owned.
She was born in 2001. She is sickle hocked, fine boned, has poor feet and only has 2 1/2 teats that the calf can suck. But, she consistently raises a good calf, that does not seem to inherit her poorer qualities, and that weighes up in the top end of the calves every year. In fact, her heifer calf from this year is in the replacement pen. This girl would have gone this fall, since it was one of those 'give me a reason to cull' years. But she is so ugly and pathetic looking that we figured we would do better on her to keep her and let her raise calves, than we would have done if we had sold her.
There is also another cow that is an ugly, scrawny old girl, she is nearly impossible to keep weight on, but she is going to be 10 years old in the spring. She has had 2 sets of twins, raised one of each set and always has one of the biggest calves in the fall.