Alterations in levels of various host antioxidant factors in turkey knockdown syndrome

Five components (selenium, glutathione peroxidase, copper, superoxide dismu tase, and vitamin E) of I-he antioxidant system of turkey poults were exami ned to determine if they play any role in the knockdown (KD) syndrome. All flocks were provided with feed formulated to contain monensin at 54-60 g/to n. Flock data were analyzed as a case-control study with three treatment gr oups (KD-affected and unaffected turkey poults from a KD flock and poults f rom an unaffected flock [control]). Affected turkey poults had lower (P < 0 .001) serum vitamin E levels compared with unaffected poults from KD flocks or poults, from unaffected flocks. No significant differences were observe d for the other parameters evaluated hut there was a trend towards lower co pper and superoxide dismutase values in affected birds. It appears that ser um vitamin E concentrations in turkey poults may play a significant role in susceptibility to or protection against KD syndrome. Other components of t he antioxidant system may also be involved, and complex interactions among several body systems may be critical.