Effects of Endotoxin Contaminated FSH-preparations in Heifers

摘要

Superovulation is one important step in embryo transfer. By administration of gonadotropins a multiple ovulation is induced. Several FSH-preparations for superovulation are commercially available. Most of these consist of extracts from pituitary glands from slaughtered farm animals. According to some studies (Yagoda et al. 1990a,b), drugs can easily be contaminated with endotoxins. Endotoxins are commonly found in the environment, for example in water and silage, and in medical preparations (Yagoda et al. 1990b). Endotoxins can have several effects on animals and on human beings. They can cause endotoxaemia with effects like fever, ruminai stasis, release of prostaglandins, leukopenia and decrease of the plasma levels of calcium, zinc, iron and bile acids (Aiumlamai 1991). The severity and range of the effects caused by endotoxin are very dose-dependent. Animals receiving a low dose of endotoxin may not show the clinical signs of endotoxaemia, but can still have subclinical changes like leukopenia, prostaglandin release, mild hypocalcaemia and decreases in the plasma levels of zinc and iron (Yagoda et al. 1990b, Kindahl & Aiumlamai 1991). For humans, 5 EU/kg bodyweight is considered to be the threshold dose for appearance of clinical effects. (Anon. 1987).