Additionally, humans FREQUENTLY choose to adopt rather than risk passing on a genetic abnormality to a biological child.
The only difference here is that we would be making the decision for the tigers since, as everyone would agree, they don't have the ability to understand the consequences and make the decision themselves.
1.5-2% of children are adopted in the US. About 50% of those children's parents adopted due to infertility, of which an even smaller fraction is voluntary infertility.
I wouldn't say that is something that humans due frequently, and is probably limited to a small set of cultures, and an even smaller subset of parents with both the knowledge and fortitude to make that decision.
I'm an adoptive parent and know several dozen other adoptive families. I have never personally met someone who chose to adopt to avoid the risk of passing on genetic abnormalities.
Unfortunately, I also know some who chose to ignore the advice of their genetic counselor and now have 3 lovely, but severely mentally disabled children (Fragile X run amuck) who will never be able to live independently.