The Study Of Preventing Medicine And Its Field Trial Of Locoism In Livestock

Locoweed are the poisonous plants of Oxytropis and Astragalus, which caused a large number of domestic animals dead after eating these plants. According to the researching of model Toxicology, the poisoning mechanism of Locoweed is that the consituents inhabit the active ofα-mannosidase. At present, the measures of prevention are chemical eliminating and manpower removing weeds, which have less effect. The study carried out the researches of antidotes and field trials of prevention animal's poisoning according to its main toxic constituents and mechanism of poisoning. The main results are as follows.1. There are 36 species of Oxytropis including 9 species with serious poisoning danger in Qinghai province, which distributing in 30 counties of Haixi, Hainan, Huangnan, Haibei, Yushu, Haidong cantons. There are 221.6×104 hm2 of Oxytropis distributing areas accounted for 6.62% of total pasture area being used as grazing. This distributing number is significantly higher than it of countrywide. The highest strength of Oxytropis distribution is 400 strains/m2, and the lowest is 1 strains/m2, and the cover degree of Oxytropis arrived to 70% to 90% in some places.2. The effects of 7 medicines on preventing poison of Oxytropis to ship were studied. O.kansuensis powder of 10 grams per one kilogram of body weight were given to 40 sheep through rumen fistula in each day, at same time, the animals of experiment's group were given 7 medicines of preventing poisoning of sheep. The results show that the sheep of control group appeared toxic symptom at 15th to 18th days, and animals of experiment's groups given different antidotes appeared toxic symptom at 26th to 31th (Jifan A), 29th to 31th (Jifan B), 27th to 30th (Jifan C) and 35th to 51th (Jifan E) days, which showed antidotes have effects on prevent poisoning of oxytropis to sheep and Jifan E has best effect among all medicines. The results of testing biochemical indicator were as follows: The active of blood glutamic oxaloacetic transaminase (GOT) of experiment's sheep began to increase at 7th day of experiment. The actives of alkaline phosphatase of animals given Jifan A and B were no obvious changed during the time of experiment, but the actives of alkaline phosphatase of other groups and control began to increase at 7th day of experiment.3. The concentrations in blood and pharmacokinetic parameters of"Jifan E"were tested using 4 sheep taking orally it. The results show that the relationship between plasma concentration of medicine and time fitted to the first order model. Pharmacokinetic parameters were as follows: absorption rate constant(ka) is 2.03±0.77 h-1, and elimination rate constant (ke) is 0.36±0.03 h-1; and time to peak (Tmax) is 5.65±0.77h; and the half increasing absorption phase (T1/2/ka) is 3.15±0.18h; and the half-life of elimination phase (T1/2/ke) is 1.24±1.87 h; and the peak concentration (Cmax) is 4.98±0.68 mg.L-1; and the area under the concentration-time curve (AUC) is 27.65±3.54mg.h-1.L-1; and the average clearance rate (ALB) is 0.53±0.07 mg.kg-1.h-1; and the body apparent volume of distribution(Vd) is 1.93±0.08 L.kg-1.4. The acute toxicity, sperm abnormality and micronucleus test of"JiFang E"were taken out using Kunming mice fed it though mouth. The LD50 of"JiFang E"for mice is 2808mg/kg; and 95% confidence limit is 2015mg/kg to 3905mg/kg, which were calculated using simplifying probability unit method. This result showed that"JiFang E"is low toxic medicine. The"JiFang E"has damaging effect on mouse sperm when the dose arrived to 1/4 LD50 (702mg/kg.bw). The"JiFang E"has mutation effect on mice bone marrow cells when dose over 1/2LD50 (1404mg/kg.bw).5. Using investigation and data collection methods, the hazard of Oxytropis poisoning to grazing sheep was surveyed in Riyue Township of Huangyuan County, and the prevention field trial of the"JiFang E"was carried out by randomly selecting 1040 let-sheep in Riyue Village of Huangyuan County. The Oxytropis poisoning of grazing sheep was occurred in the hay season of spring and winter. The grazing sheep have not show any Oxytropis poisoning after use"JiFang E", and the rate of locoism has decline from 2.97 percent to zero, and the survival rate of lamb was improve from 94.8 percent to 97.1%. The 1024 sheep taking"JiFang E"did not appear toxic symptom, which shown it has obviously preventive effect.