Changes in liver glycogen of broilers during coccidiosis.

Abstract

Liver glycogen levels of broilers with Eimeria acervulina, E. Brunetti, or E. tenella fell during the acute phase of the infection with the maximum effect at 5-6 days post-inoculation (DPI). During the early recovery phase (6-8 DPI), liver glycogen levels in the E. acervulina-infected birds increased to levels up to 3 times greater than those found in uninoculated control birds. A lesser increase was occasionally seen in E. tenella-infected birds. Pair feeding studies showed that the decrease in liver glycogen was not related to the amount of feed consumed. The magnitude of the glycogen overshoot at 7 DPI was not related to the depression of weight gain at 5 and 6 DPI. When feed was withheld from birds, liver glycogen levels of uninoculated control birds fell rapidly within 1 h after feed withdrawal. In birds infected with E. acervulina, liver glycogen levels remained high even after 3 h starvation. Injection of glucagon indicated that glycogen could be mobilized in both infected and uninfected birds.