2. The hormone PMSG

Pregnant Mare Serum Gonadotropin (PMSG) is a pregnancy hormone found in the blood of mares. It is produced in the chorion (foetal membrane) during early gestation, approx. from day 40 to 140. PMSG does not appear in the urine of mares. Because of its close relationship with the human pregnancy hormone hCG (human chorionic gonadotropin), the hormone is also called equine chorionic gonadotropin (eCG).

Use and effects

PMSG is used for the induction and synchronisation of oestrus in farmed animals, in particular pigs. Through the administration of PMSG it is intended that the sows come into heat and can be artificially inseminated at the same time, and the births take place on the same day. Thus, working processes for piglet producers become more efficient. Ceva’s marketing brochure defines the goals of PMSG use as follows: “higher insemination rate, higher piglet index, less non-productive days and better concentration of work.” Other animal species also treated with PMSG include sheep, goats and cattle.

Described (side-)effects of PMSG with pigs are, among others, superovulation due to the formation of an exceptionally large number of follicles. The superovulation leads to more piglets per litter. Often, the sows have more piglets than teats and cannot feed them all. The greater the number of piglets, the higher the risk of animals being born weak and malnourished. The “surplus” piglets are often left to die; cases have become known where they were struck dead. In some establishments the surplus piglets are fed by so-called foster sows. Furthermore, the administration of PMSG induces and accelerates the development of puberty in sows. Nowadays, the induction of puberty has no legitimacy anymore, as according to scientific studies the lifetime production and lifespan of a sow increase the better she is sexually developed when she gives birth for the first time, if i.e. the ovaries are fully developed.

Alternatives to PMSG

There are numerous alternatives available to breeders for the induction and synchronisation of oestrus in farmed animals, and their efficacy is very similar to PMSG according to studies and practical experience. In Germany, there are 36 synthetic hormones available on the market for different animal species and indications. Eight products are available for use in pigs, for example Peforelin. Scientific studies have shown that this substance is equally suited like PMSG to stimulate and synchronise oestrus in young and old sows and that its use achieves comparably good fertility performance. Contrary to PMSG, Peforelin does not lead to superovulation (larger litter sizes) nor to induction of puberty. 

It is important to note that synchronisation of cycles is also possible with hormone-free methods, so-called zootechnical measures. Such methods include optimal nutrition and lighting, contact with sows in oestrus and boar contact. They are, for instance, used in organic farming, where the systematic use of fertility hormones is prohibited.

Footage of investigations carried out in 2015 showed emaciated mares, weakened by the high blood loss and permanent gestation. Mares that were covered in scars from beatings. Supervision and medical care of the animals could be observed on none of the blood farms. Video footage of a blood extraction session showed how mares were forced into the restraint boxes with brutality and abuse. About 30 minutes of the recorded five hours of footage were scenes of pure violence. The animals were hit with sticks, wooden boards, and whips. Electric prods were used as well. An employee was observed kicking a weakened mare until she collapsed and remained on the floor.

Investigations from May 2016 until April 2017 showed that despite the promises of authorities and pharmaceutical companies, the situation had not improved. Mares were still violently thrashed to be moved into the blood extraction boxes, they were still left to fend for themselves in fields and forests, injuries remained untreated and foals were still systematically aborted. Our team visited again all blood farms in Uruguay known since 2015. Based on our comprehensive investigations, we assume that about 30% of mares drop out of the production every year: they either die on the pastures or are sent to EU-approved slaughterhouses when they no longer become pregnant.

Video footage obtained in Argentina and Uruguay in January and April 2018 clearly showed that 2.5 years after the first publication about PMSG production was released, the abuse of mares producing the valuable hormone still continued. Despite the allegations of the import companies to have taken control of the situation with trainings, audits and new manuals (which are not legally binding). And despite the new manual of good animal welfare practices for PMSG production introduced by the Uruguayan ministry in June 2017. The videos showed mares being abused with iron hooks or cruelly mistreated by having their genitals stabbed with sticks. Injured, sick or emaciated mares still did not receive veterinary treatment but were left to their own devices on vast forest pastures.

5. The legal situation of PMSG production

The production of PMSG takes place in a legal grey area: Officially, the Ministry of Livestock, Agriculture and Fisheries in Uruguay and the SENASA (Servicio Nacional de Sanidad y Calidad Agroalimentaria) in Argentina are responsible for the supervision of PMSG production. However, Argentina still has no specific legal requirements for PMSG production and thus legal foundations for controls are still missing. The Uruguayan ministry published an animal welfare manual for PMSG production in June 2017. However, it contains mainly non-binding recommendations instead of mandatory requirements and has considerable loopholes. For example, it is not defined how much and how often blood can be taken from the mares or how abortions have to be carried out. Foals still can be aborted until day 105 of pregnancy, which corresponds to the existing practice.