Behavioral and Metabolic Response to a Low Dose Administration of Bacterial Endotoxin for Early Detection of Illness in Goats

Eighteen indigenous female goats of 7-8 months of age with average BW 9.8±1.04 kg (mean±SE) were randomly distributed into three equal groups (CON, LET and HET). Bacterial endotoxin (Escherichia coli O55:B5) was injected intravenously to treatment group animals at low (LET; 0.2μg/kg BW) and high (HET; 0.4μg/kg BW) doses while the animals of control (CON) group were administered an equivalent volume of normal saline. Heart rate, rectal temperature, feed and water intake and behavioral changes were studied as the main indicators of the response together with selected blood metabolites. Both the endotoxin treated-groups showed almost similar response of depression and lethargy followed by biphasic shivering, increased (P 0.05) rectal temperature with decrease activity, feed (P=0.054) and water (P 0.05) consumption. No significant differences were observed in studied behavioral, heart rate, hematological (Hb and Hct), serum protein and activity of ALT. Plasma glucose level, on the other hand, was reduced at 3h post-injection in both LET and HET as compared to CON. The serum activity of AST exhibited a significant (P 0.05) increase in HET group as compared to LET or CON. Low doses of endotoxin (~0.4 μg/kg BW) in goats mimic low concentration of circulating bacterial endotoxin, which could be ascertained from the associated behavioral and febrile responses along with changes in selected blood metabolites.