Subject: animal donors with human genes

I am in a Genetics class that covers organic, inorganic, biochemistry, 
and a little biology. In class today the discussion came to Gene Action.  
Under my husbandary section of my notes is a subtopic - animal donors with 
human genes.  I hear this is controversial among those about animal 
rights, but my question is if one can clone a human, why would this be an 
option any longer?  Another question I have is ( this stastistic may be 
outdated, but...) of the known 2100 genes on the chromosones in the human 
body about 450 are disease producing.  Since we can now clone animals, 
kidneys, and I assume humans too, why wouldnt there be a way to splice out 
the disease producing genes to create a human that can't get (genetically) 
diseases? 

Re: animal donors with human genes