Participation in Forum on March 1, 2017
It could be argued that the 2 houses were "seeded" with the vaccine strains as the dominant strains after vaccination and in subsequent cycles and in turn showed greater sensitivity to the anticoccidial. Generally with live anticoccidial vaccination the idea is to replace the field strains with the more precocious but less pathogenic vaccine strains.
This member had joined Engormix
September 29, 2016