What does it mean that Secretariat was syndicated?

Individuals purchased breeding rights at a fixed price....which was done (February 1973) well before he rewrote the record books in the Triple Crown and was a tough sell within the industry (as depicted quite well in the recent movie, but delved into much better in Bill Nack's book - "Secretariat: The Making of a Champion," which fully explains why Penny Chenery had to sell 'Big Red' in this manner once his racing career ended at age three, which was part of the deal).