You can't use "once in a blue moon" in that sentence. Even if you did it only once in October, one month is too short a time to use that idiom.
Here,In October of 2010, we (twice) imported two pigeons from the USA into Taiwan.
If you did it twice or x number of times, say that.
(2) We plan to use them to mate and hope that will bring us fruitful good results.
I wouldn't use "fruitful' in that sentence. The word "fruitful" itself means good results, so "fruitful results" is redundant. I prefer a basic word like 'good'.
Or you can say '...use them to mate and hope that will be fruitful.