Whoever bought the pair was probably a slaughter buyer. Being a buyer he sent the cow to kill and sold the calf. Probably made a profit separating them. You could see this often later this spring as the slaughter price gets higher.
Example the pair brings $750 and the cows weighs 1200lb and has a baby calf. If the cow is worth .55 that makes her worth $660 and say the baby calf brings $140 that is a total of $800. Whoever brought the pair to market thought they were worth more together but the buyer knew better and split them.
dgott: Not sure where you live but at this time of year there are always people looking for a calf that can be transplanted onto a cow that has lost her calf, so prices on young calves can be pretty strong? While I personally think this is wrong thinking, there are many people who believe in giving a young cow a second chance.
Probably the pair were at the auction for a reason? Poor udder/milk, old, or mean? That type of cow should be going to slaughter. The buyer was buying her for slaughter and saw an opportunity to make a dollar on the calf.
You did not start age of cow, condition, ect. As a former order buyer , I am sitting there with a order for 25 slaughter cows , it does't matter if a cow comes through with a calf , if she can work in my order , I would buy her and split the calf off resale the calf to lower the cost of the cow. Many many times , I would make a farmer pay more than the pair was worth if he got to bidding against me , I knew more what the cow is worth to me than he would.
I would go call back to the office and find about how the market was working and a just my price up or down the scale as the sale went on. Its a numbers game buy as cheep as u can and sale for as much as u can get. Is it fair yes. One time yrs ago I adjusted the price on my bought cattle 8 times as the market shifted up and down during the sale. I had a order for a load of slaughter cows and the numbers were up on the cows at the yard that day so all the buyers soften the market and bought some cheaper cows for slaughter.