The efficacy of ivermectin against Thelazia rhodesii (Desmarest, 1828) in the eyes of cattle.

One hundred cattle with confirmed natural infections of Thelazia rhodesii were included in three studies to evaluate the efficacy of ivermectin for the treatment of eyeworm infection. Thelazia rhodesii were counted in situ in each eye of each animal on Day 0 (prior to treatment) and the cattle were paired by the number of worms, within categories of sex, age or number of infected eyes. Within each pair, one animal was randomly assigned to serve as an untreated control, while the other was treated subcutaneously with ivermectin at 200 micrograms kg-1 body weight. Eight days later, parasites were recovered from each eye separately, identified and counted. In each study, significantly (P less than 0.01) fewer T. rhodesii were collected on Day 8 from ivermectin-treated cattle than from controls. Overall, the reduction in numbers of T. rhodesii collected from treated cattle was greater than 99% (P less than 0.05) relative to controls, with reductions of 100% being recorded in two of the three studies.     

The effect of pig farming on copper and zinc accumulation in cattle in Galicia (north-western Spain)

Copper and zinc are frequently added at high concentrations to pig diets as growth promoters. Livestock grazing pasture contaminated with pig slurry may, therefore, be at risk from excessive intake of these elements. High liver copper concentrations have been detected in cattle from the agricultural region of Galicia (NW Spain), especially where there is intensive pig farming. The aim of this study was to evaluate whether pig farming does affect accumulation of copper and zinc in cattle in Galicia. Hepatic copper and zinc concentrations in calves were elevated in areas with naturally high levels of these elements in the soil. The densities of young pigs (piglets and growing-finishing pigs), but not reproductive sows, also influenced copper accumulation in calves. Liver copper levels in calves were significantly and positively related to the density of young pigs in the region. In areas with the highest pig densities, more than 20% of the cattle analysed had hepatic copper concentrations that exceeded the potentially toxic concentration of 150 mg/kg fresh weight. There was no evidence that zinc accumulation in calves was affected by pig density.     

The effect of estradiol cypionate (ECP) on ovarian follicular development and ovulation in dairy cattle.

The efficacy of estradiol cypionate (ECP) for synchronizing ovarian follicular development was determined in lactating Holstein-Friesian cattle. In Experiment 1, 13 cattle were given simultaneous intramuscular (i.m.) injections of 100 mg progesterone and 0 (control), 0.5 or 1.0 mg ECP on Day 3, after a synchronized ovulation (Day 0). Maximum diameter of the dominant follicle of Wave 1 was significantly larger in control cattle than in those given 0.5 or 1.0 mg ECP (means: 15.7, 13.2, and 12.9 mm, respectively). Mean day of emergence of Wave 2 was significantly later in controls than in those given 1.0 mg ECP, with the 0.5 mg group intermediate (Days 10.2, 8.8 and 9.5, respectively). In Experiment 2, 14 cattle were given a CIDR-B and IM injections of 1 mg ECP and 50 mg progesterone without regard to stage of cycle (treatment = Day 0). On Day 8, the CIDR-B was removed and 500 micrograms cloprostenol injected, IM. Mean days of wave emergence (Day 3.4; range: -2 to 7) and ovulation (Day 12.1; range: 10 to 14) indicated that ECP had limited efficacy for synchronizing follicular development and ovulation in dairy cattle when given at random stages of the estrous cycle.     

The effect of season on reproduction in dairy cattle

A survey was carried out in North West Tasmania to compare the breeding performance of 2,068 cows in 27 dairy herds--15 herds calving in spring and 12 in autumn. The percentage of cows submitted to artificial insemination for the first time in the first 24 days of the mating period was 87% for the spring calving group and 75% for the autumn calving group. Figures for non-return-to-service rate over the subsequent 21 days were 72% and 55%, respectively. The difference in breeding performance associated with time of calving was not attributable to age, calving to mating interval or on cow condition or daily milk fat yield at 3 weeks (+/- 1 week) after the start of mating.     

The effect of copper on intact cattle erythrocytes

The effect of copper on intact cattle erythrocytes was investigated in vitro. When treated with copper, a decrease in the GSH content, accumulation of copper in the cell, loss of potassium and gain of sodium, cross-linking of membrane proteins, and echinocytic transformation were observed. All of these phenomena seem to be caused by a potent oxidant action of copper. These cytotoxic effects of copper were markedly inhibited by the addition of bovine serum albumin in the incubation medium. These results may help to understand the mechanism of hemolysis associated with copper poisoning in vivo.     

牛胃药的临床效果观察

根据中兽医学理论和牛羊生理特点 ,以陈皮、柏香子、鸡矢藤、马钱子、虎杖、辣蓼、青蒿、元明粉、生石膏等为原料经过加工精制而成的牛胃药散剂 ,经试验表明 :对牛羊常见的消化系统疾病有较好的治疗效果。对追踪调查的 4 14头牛的前胃弛缓、消化不良、瘤胃积食及便秘治愈率分别为 96 .6 %、95 .2 %、91.0 %和 86 .6 %。对追踪调查的 75只羊的消化不良治愈率为 96 %。     

Borna disease in cattle (consensus report)

Short survey on definition, occurrence, cause, importance, pathogenesis, clinical findings, course, postmortal lesions, treatment, prevention and eradication of Borna disease in cattle.