How much will 28g of raw minced lamb weigh when cooked?!
It depends on how much fat there is and if you cook it in a way that renders the fat out.
If it keeps all the moisture and it's lean meat it will weigh about the same.
If it is 20% fat and you cook it in a way that takes out the fat and some moisture it will lose figure 15% of it's weight (you can't get all the fat out, and fat weighs less than meat.)