Inbreeding and outcrossing have to managed very carefully with captive populations to ensure the long term stability of the population. I'm not going to discuss it further in this thread, but I suggest those who are discussing inbreeding read through the following reference
This article actually gives a good overview of both inbreeding risks and outbreeding risks... It took awhile to find a free online copy
Edmands, Suzanne; 2007;Between a rock and a hard place: evaluating the relative risks
of inbreeding and outbreeding for conservation and management; Molecular Ecology 16, 463–475
Note; that inbreeding and outbreeding effects can be easily confused and the recommendations seen in the discussion section of the article on attempting to prevent the occurance of the effects of inbreeding/outbreeding. Both of these are significant risks and can have significant effects on the survivial of a captive population as the results of either/both can reduce the ability of the animal to resist disease pathogens common in captive situations (like saprolegnia..). One of the biggest problems is that negative results of outbreeding/out crossing may take as much as three generations to appear and can result in the death of the population.
Other relevent references for those interested...
SpringerLink - Journal Article
CJO - Abstract - Supplementation or <em>in situ</em> conservation? Evidence of local adaptation in the Italian agile frog <em>Rana latastei</em> and consequences for the management of populations
ScienceDirect - Fisheries Research : Heterosis and outbreeding depression: a multi-locus model and an application to salmon production
As noted above, this is going to be my sole comment on inbreeding/outbreeding in this thread. There are other threads where it has been well discussed so those who are interested should check it out there.