Jago M V, Culvenor C C
CSIRO Division of Animal Health, Animal Health Research Laboratory, Parkville, Victoria.
Aust Vet J. 1987 Aug;64(8):232-5. doi: 10.1111/j.1751-0813.1987.tb09689.x.
Quantitative toxicity studies were carried out in sheep using corynetoxin, tunicamycin and toxic annual ryegrass (Lolium rigidum). Sheep were very sensitive to these toxins. The lethal dose was about 35 micrograms/kg bodyweight for pure tunicamycin given by subcutaneous injection and 3 to 5 mg/kg for corynetoxin administered orally as slurries of bacterial galls of known corynetoxin content. The total lethal dose was of the same order, whether given as a single dose or as repeated smaller doses, the maximum interval tested being 9 weeks between doses. This finding indicates that a second exposure of animals to toxic rye grass in the one season would present a greater risk than would a first exposure to the same field. It also demonstrates the advisability of the monitoring of pasture levels of gall contamination, as levels below those that produce clinical signs of the disease may still contribute to an accumulating burden of toxicity.
使用棒曲霉素、衣霉素和有毒一年生黑麦草（硬直黑麦草）对绵羊进行了定量毒性研究。绵羊对这些毒素非常敏感。皮下注射纯衣霉素的致死剂量约为35微克/千克体重，口服已知棒曲霉素含量的菌瘿浆液形式的棒曲霉素时，致死剂量为3至5毫克/千克。无论给予单次剂量还是重复较小剂量，总致死剂量都处于同一水平，测试的最大剂量间隔为9周。这一发现表明，在同一季节动物再次接触有毒黑麦草比首次接触同一田地的黑麦草风险更大。这也证明了监测牧场菌瘿污染水平的可取性，因为低于产生该疾病临床症状的水平仍可能导致毒性负担的累积。
