Cholinesterase Activities and Oxidative Stress in Cattle Experimentally Exposed to Nitrate/Nitrite in Cultivated Pasture with Different Fertilization Schemes

摘要: Background: Nitrate and nitrite poisoning is associated with pasture intake that has high nitrate levels leads to acute methemoglobinemia. Pasture may accumulate under certain conditions, such as excessively fertilized soil or environmental conditions enhance the N absorption (rain preceded by a period of drought). After ingestion plants, this substrate reaches rumen and, in physiological reduced afterward ammonia. The aim study was evaluate changes cholinesterase activities oxidative stress caused subclinical for cattle fed Pennisetum glaucum three different fertilization schemes. Materials, Methods & Results: In order perform experimental poisoning, cultivated paddocks: nitrogen topdressing (urea; group 1), organic fertilizer (group 2) without 3; control). accumulation forage evaluated diphenylamine test. food fasting 12 h, nine bovine were randomly allocated one groups fresh (ad libitum) from respective paddock. time points beginning (0, 2, 4, 6 9 h) heart rate respiratory frequency assessed, well mucous membrane color behavioral changes. Blood samples jugular vein into vials anticoagulant collected. From blood samples, serum levels, acetylcholinesterase (AChE) butyrylcholinesterase (BChE) enzyme activity evaluated, through following parameters: nitrate/nitrite (NOx ), thiobarbituric acid reactive substances (TBARS) oxygen species (ROS), beyond antioxidant system measurement catalase (CAT) superoxide dismutase (SOD). test positive 1 so presented 3.16 mg/kg, 2.98 mg/kg 1.67 1, 2 3, respectively. addition, cows demonstrated increased (P < 0.05) serum, compared other groups, greater after h 0.05). AChE BChE showed significant increase at 4 (AChE), 3. Also, NOx lower animals respectively, when Furthermore, ROS TBARS significantly higher CAT experiment, but on hand, decreased 1. Nevertheless, only reduction h. SOD groups. Discussion: It concluded urea nitrite, causes cattle. conjectured assist understanding pathophysiology poisoning.