First off welcome to BYH. Now, from someone who has bought more than my share of calves from auctions over the years....it is a BIG GAMBLE when you buy one from the auction when you are experienced in cattle, inexperienced is even trickier. So, that said; yes you need a temp on her. Do not make the hole bigger in the nipples in the future as they can and will get the milk into their lungs when they go to sucking too fast and if you do not hold it at the right angle. A calf needs to hold it's head to drink out of a bottle at the same angle as off a cow and that means it needs to be a little lower than you think so that she has a bit of a "dip" in her neck/throat.
In other words, it shouldn't be so high that the milk seems to run directly from the bottle to the mouth down the throat... it will get into the lungs every time. That could be why she suddenly stopped and why she is coughing. If that's the case, hopefully it wasn't too much before she stopped; it can kill her (she will actually drown) or she can develop pneumonia from the fluid in her lungs. Most people think they aren't drinking fast enough....a cow's teat has an opening that is little bigger than a large pencil point and they have to work a bit to get the milk. That is why the nipple holes are sized the way they are. It is necessary for a calf's jaw muscles to develop and so they need to work at it, and so that it goes down the right "tube".
Because she is an auction calf you probably won't know anything about her. She could have runny manure from the stress of being transported to the sale, exposure to a ZILLION different "bugs" that her system has never encountered before, or someone could have gotten rid of her because she was a problem with loose manure and couldn't get straightened up. She could have a rotacorona virus that is a B***H to deal with, and can be a chronic problem if it doesn't kill them. Also e-coli can cause scours, and coccidia can be a problem.
My suggestion is to take her to a vet, hopefully they can check the manure and maybe figure out if she has an intestinal virus of some sort, and can check her lungs to make sure she doesn't have liquid/congestion in them.
1 1/2 to 2 months is also a tough age because they will be starting to eat solids, hay and grain, and she might have been getting grain and it caused her to scour too. There are too many variables to even begin to diagnose her. Either ask an experienced cattle person in your area or take her to a vet. Be prepared to sink some money into her because most vets are in the $100. an hour range, plus any lab work and drugs/medicines you have to have.
If you can get her on the right track, then a couple of things. ONLY buy milk replacer that is ALL MILK; NOT SOY BASED. You don't need anything medicated, just ALL milk. She should be eating and a fine hay like a 2nd or 3rd cutting orchard grass will be the most palatable. Do not feed her alfalfa, she is too young and the protein will cause her to scour. A good calf grain, usually called a calf grower will be in the 14 to 16% protein range and that is what she will need.
She needs a draft free place but not closed up tight. Sunshine is good and clean straw/hay/shavings or something for bedding.
Do you have any other animals? Any experience with any other livestock to draw on ? Is there a specific purpose that you bought a calf to raise? Beef for the freezer or ???
