Estrumate injection

Estrumate, a synthetic prostaglandin, is a potent luteolytic agent for use in cattle and horses. Cloprostenol is structurally related to Prostaglandin F 2? (PGF2?). Both cause functional and morphological regression of the corpus luteum (luteolysis). Luteolysis is usually followed by a return to oestrus 2 to 4 days after treatment (with normal ovulation). Estrumate is specific in its luteolytic action, it is ineffective when there is not a corpus luteum present. For example, there is a refractory period of 5 to 6 days after ovulation when animals are insensitive to the luteolytic effect of prostaglandins. Estrumate has a wide safety margin. There is no deleterious effect on progeny conceived at the oestrus resulting from treatment with Estrumate. ESTRUMATE IN CATTLE The life cycle of the corpus luteum (CL) is terminated by the release of the uterine luteolysin. Thus an exogenous luteolytic agent such as Estrumate can effectively shorten the cycle length, provided it is administered at times when a fully functional corpus luteum is present. There are short periods in the cycle when the system is insensitive. These are the periods directly preceding and directly following oestrus. That is, the 4 to 5 day period in the late luteal/early follicular phase when the old corpus luteum is regressing and the 5 to 6 day period after ovulation when the new corpus luteum is developing. Between these periods there is a 12 day period when the fully functional corpus luteum will respond to Estrumate. Controlled Breeding Programmes Before a programme is planned, the farmer and veterinarian should discuss the expected results and limitations of the programme, reviewing the herd’s breeding history, herd health and nutritional status to decide if it is practical in the particular circumstances. For any successful controlled breeding programme using prostaglandins: • Cows and heifers must be normal, non-pregnant and cycling (an examination should be performed) • Cattle must be in good breeding condition and on an adequate or increasing plane of nutrition. • Proper programme planning and record keeping are essential (animals must be identified). • If artificial insemination is used it must be performed by competent inseminators using high quality semen. • Oestrus observation is important, this is greatly assisted by use of tail paint. • It is important to understand that Estrumate is effective only in animals with mature corpus luteum (ovulation must have occurred at least 5 days prior to treatment). Cattle which respond to a single prostaglandin injection will normally do so within 6 days of treatment. Please refer to Estrumate publications for options on different programmes. Therapeutic uses Several reproductive problems in cattle associated with luteal function will respond to luteolytic treatment with Estrumate. A single dose of Estrumate is likely to be highly effective in the following circumstances: • Sub-oestrus (or non-detected oestrus, or silent heat) Sub-o