PHYSIOLOGICAL EFFECTS OF TIMBER MILK VETCH, ASTRAGALUS MISER VAR. SEROTINUS, ON SHEEP

Abstract

The physiological effects of timber milk vetch (TMV), Astragalus miser var. serotinus, on sheep were studied using wethers kept in pens and yearling ewes under range conditions. Three of the four wethers fed 100% TMV exhibited characteristic symptoms of poisoning, which included backward flexion of the fetlock joints, paralysis of the hind limbs and incoordination of movements. Yearling ewes that were fed TMV under range conditions exhibited symptoms of poisoning especially when they were excited or after being shipped for slaughter. The presence of longitudinal ulcers in the intestine and elevation of the activity of serum glutamate oxaloacetate transaminase were characteristic of toxicity in both the groups. The concentration of thiamine in the blood was within the normal range, indicating that the beneficial effects of thiamine as a therapeutic agent in TMV poisoning may be indirect. After the TMV was cut, dried and pelleted the misertoxin content dropped from 2.57 to 0.90%.