Resistance between Nellore, Curraleiro Pe-duro and Pantaneiro cattle to experimental toxic action of Palicourea marcgravii.

Palicourea marcgravii is the most important toxic plant in Brazil due to its acute toxicity (sudden death), palatability, cumulative effect and broad geographical distribution. The study aimed to evaluate the resistance between cattle of different breeds by experimental intoxication of P. marcgravii. Eighteen males were randomly divided into three groups (Nellore, Curraleiro Pe-Duro and Pantaneiro), six animals in each group. All animals were experimentally intoxicated with P. marcgravii at 0.5 mg/kg of equivalent sodium monofluoracetate acid, receiving one single oral dose. All cattle presented symptoms and the toxic plant caused death in all cattle of the Nellore and Pantaneiro breeds and only three Curraleiro cattle. No changes were observed in the leukogram, fibrinogen, albumin, total protein and bilirubins. Hyperglycemia and increased of aspartate transaminase, creatinine kinase, urea and creatinine were detected in all breeds. Changes in the values of the gamma glutamyl transferase were individualized and did not follow a standard response. Fourteen cattle presented the histopathological findings of renal hydropic degeneration. The lower death rate of Curraleiro cattle indicates a higher resistance than cattle of the Nellore and Pantaneiro breeds.