About 30 years ago, I had some long yearling Corr steers heifers in a pasture, It was a 15 acre bermuda hayfield, with a pole barn on it, that I would put that hay in every time I baled it. I put those heifers and steers in it in November after the season was over. My intention was to breed the heifers in March, and sel the steers for dogging steers to a producer. This place was 30 minutes from my house. Man next door, single man with 2 little kids, had bought two Jeresy bottle calves that spring, about March or April. I would let him get hay to feed his calves that he had in about an acre lot , in exchange for keeping my hay feeder full. One day when I was out there I told him he ought to just put his 2 Jerseys in my pasture, and they could eat free choice hay like mine did. I thought he had a steer and a heifer calf. Just assumed it. Well, it wasn't a steer, ..he had never cut or banded it. So, he would have been 7-8 months old that November. I was over there in January, when I saw the little son of a gun breeding one of my heifers! I figured he was just riding her, like you see steers do sometimes. Or other heifers. He would have been 10- months old at best then. Heck no...I ended up with six of them bred! Nothing more worthless than a Jer X Corr steer calf. I got 3 of each. The Corr x Jer heifers I just kept to breed with. I had already started breeding Corrs to black polled bulls to get team penning/sorting cattle, so that's what I used these for, eventually. Those steer calves just went to the practice pen for tie-down roping. They were nearly two before they had enough horn for team roping.
And on one of my Update threads, I told about a 8-9 month old Gyr bull getting a cow in calf.