Susceptibility of broiler chickens to Clostridium botulinum type C toxin

As broiler chickens aged during the first eight weeks of life, they decreased in susceptibility to the lethal effects of Clostridium botulinum type C toxin. Eight-week-old broilers were 2,000 times less susceptible to the lethal effects of the toxin than hatched chicks. Different broiler crosses showed similar susceptibility to the lethal effects of type C toxin at seven weeks of age, but 2.5 times more toxin was required to produce lethality by oral inoculation than was required by subcutaneous inoculation.