What Is ICSI? (Credit: David Maisonnette) By Julie J. Bryant It has been more than 20 years since Colorado State University took the technique used in rabbits, cattle and finally, humans, to produce the first “test tube” horse, and when the Fort Collins-based university introduced “Fire Cracker” to the world, the field of “assisted reproduction” gained a new tool known as intracytoplasmic sperm injection, or ICSI. Fire Cracker was the first among thousands of foals that have since been produced through ICSI. For some, the procedure has not been a lifesaver, but a “life giver” as a last hope for extending the reproductive life for horses whose genetics make champions.