One option under these conditions is to use F1males, generation after generation. Under such
a system, the original local females are mated to F1 males, resulting in offspring that are 1/4
exotic. These quarter-blood females are, in turn, mated to F1 males, resulting in females that are 3/8 exotic. After a few generations the animals would be very close to half exotic. This system introduces exotic influence into the population, but never uses or produces any animals that are more than half exotic.