Many new farmers buy heifers or cows from other farmers to start their dairy projects. Starting with a poor animal will set you back years in lost returns on your capital, on employed labour and on your time.
You should not start with just any heifer or cow that an unknown farmer or neighbour, relative, friendly farmer or broker is selling. Many of these sellers will say various reasons, when asked, why they are selling the animals. Examples include paying school fees, hospital expenses, legal fees and so on. While this may be true, it may also true that the reason the specific cow is chosen for sale is because it has a hidden problem.