I use to buy a replacement calf to replace a calf that died. the last one I bought from a farmer that I had bought calves from before with no problems. except this one got the scours shortly after I bought it and had the vet treat it. that calf survived, but shortly after, I started getting other calves in the herd breaking out with scours. Vet said the new calf probably carried a roto (probably not spelled right) virus and affecting rest of the younger calves. I ended up tube feeding the rest of the calves that were born after I brought that one home. ended up losing all but one out of about ten calves. never bought a replacement calf since. If you buy one, keep cow and calf separate from the rest of the herd for 3 weeks to monitor health (advise from my vet.) Based on that experience, I would rather feed a good cow for a year and start over next year or cull a not so good cow. Good luck and be careful.