spondylitis is a reemerging epidemic spinal infection in male broiler chickens (5 to 7 weeks of age) as well as broiler breeder roosters (15 to 18 weeks of age). among various causative agents, enterococcus species and in particular e. cecorum, a gram-positive bacterium as a gastrointestinal flora of birds, have mostly been isolated. on late september 2015, a number of 10 weeks old roosters wit...