More transparency is needed in the industry that collects an important hormone from pregnant mares, according to a just-published review, with the authors saying the care given to some horses is clearly unacceptable.
Collection of blood from pregnant mares for extraction of equine chorionic gonadotropin (eCG) is a critical but relatively unknown and poorly regulated practice in the countries in which it occurs, Xavier Manteca Vilanova and his colleagues reported in the journal Animals.
Their review provides a distressing account of the lives some mares face as blood donors within the industry.
The lack of formal regulatory inspections means that reports of animal neglect and abuse are anecdotal, they say.
“Several graphic videos have been posted to social media by animal protection groups, but the timing and conditions under which these videos were collected are largely unknown.”
eCG is produced by the placenta of pregnant mares and is extracted from the blood of these same mares. It is commonly used to enhance the reproduction of pigs, dairy and beef cows, sheep, and goats.
There is currently no effective synthetic replacement for this hormone, which is generally secreted for the first 80 days of pregnancy.
Horse welfare problems may arise if too much blood is collected at one time or during repeated collections, or if the mares are not managed well.
In some countries, mares are aborted several months into the pregnancy to improve efficiency since this permits them to become pregnant a second time in one year.
They say the collection of blood from pregnant mares for extracting eCG has the potential to significantly compromise broodmare health and welfare.
The practice has received significant recent attention from animal welfare organizations and governments in the European Union, they noted.
Concerns have been raised regarding how horses are kept, their handling, the volume of blood collected, inadequate veterinary care, and the routine abortion of fetuses from pregnant mares to enhance productivity.
In their review, the authors set out to explore the main horse welfare issues related to eCG production, to suggest strategies to make the process acceptable, and to encourage companies collecting broodmare blood for eCG production to carefully consider their responsibility toward these animals.
“Consistent implementation of a range of strategies is needed to protect these mares,” they concluded.
“Strengthened national or regional inspection processes would help to assure mare welfare.
“In addition, those corporations and industries producing, selling, and using eCG have an ethical responsibility to ensure that practices for oversight, care, collection of blood, and management of pregnant mares are conducted humanely.
“More transparency of the industry is needed with an opportunity for open discussion between all stakeholders.
“Production of and strict adherence to industry guidelines that promote the welfare of horses being bled for eCG production would be an important first step in protecting these vulnerable animals.”
The review team said a wide range of conditions were reported for the housing and care of these broodmares, ranging from acceptable to clearly unacceptable.
“Each facility must be judged on its own merits.”
They said the large number of mares used by the eCG industry is likely to result in workers and stock people viewing the horses as a collective, rather than as individual animals.
“If horses are not observed carefully and regularly, animal neglect and abuse are more likely.”
In many countries, mares are kept outdoors year-round on extensive pastureland. These pastures are poorly maintained. In other facilities, pregnant mares are housed indoors, sometimes maintained under very crowded and intensive conditions.
Some horses receive limited handling. Many workers on these farms are unskilled, poorly educated laborers with minimal specific training and knowledge about horse behavior and stockmanship.
“There are anecdotal reports in a few countries of abuse of these broodmares, such as by beating, prodding, dragging fallen animals, and applying electric shocks to the anogenital areas of mares.
“In some videos, broodmares are seen to fall and sustain secondary injuries following mistreatment, some of which require euthanasia.”
In these cases, appropriate and knowledgeable on-farm supervision is often lacking, and industry guidelines are largely ignored.
Veterinary care may not be available for all eCG facilities, and anecdotal reports from some countries suggest that weak, emaciated, and lame horses are often present in a herd, and infected wounds are common.
“On some farms, the lack of care results in estimated losses of between 25% and 30% of broodmares each year.”
Blood collection can also raise welfare flags. The authors say large groups of mares are herded into the holding facility for blood collection.
“In some cases, the horses may not be well socialized to humans and may be fearful in their presence, particularly when stock handlers are poorly trained in preferred methods of working with horses, and when they are rushed because of the large volume of blood collections to be done each day.
“On other farms, the mares live in close contact with the stock persons and are generally well habituated to handling.”
Mares are individually herded into restraint chutes, a halter is fitted, and this is generally used to restrain the horses for bleeding.
“The quality of design of the restraint chutes is important in terms of reducing fear in horses.”
The presence of unfamiliar people, a solid front to the chute, and negative previous experiences elicit fear-based behaviors in horses, such as balking and attempts at escape.
“Inexperienced stock people may respond with physical abuse or shouting, further frightening the horses.”
Large-bore needles are used to ensure rapid blood collection.
On some farms, it is unclear whether the best practices are used to ensure bleeding sites are cleansed beforehand, sterile needles are used and discarded after each use, collection tubes are thoroughly cleaned between animals, and adequate efforts to stop the bleeding are made afterward to ensure that painful hematomas don’t result.
Blood is harvested once or twice a week, depending on the facility and the country, throughout the approximate 80 days of eCG secretion.
“Once the blood is collected, the mares are released back to the pasture where they graze without special dietary supplementation.
“Depending on the bleeding schedules, some horses can become weak, emaciated, and sick because of a compromised immune system.
“Some of these mares will die in the pasture without further veterinary care. Again, there is a wide range of conditions on farms and body condition may not be monitored closely.”
Once eCg is no longer detectable, bleeding stops until the mare becomes pregnant again.
Some facilities allow mares to carry the foal to term and then sell the foals. On farms in Latin America, it is common for the pregnancy to be terminated so that the mare can be rebred for a second blood collection period that year.
“Abortion is accomplished by injection of abortifacients, such as prostaglandins or by manually forcing open the cervix and rupturing the fetal membranes.
“Either technique results in physical signs of parturition, with remains of aborted fetuses commonly found in the pastures.
“While it is known that mares produce less eCG after their third pregnancy, it is unknown how long the average broodmare remains within any given facility nor how culling and euthanasia decisions are made.”
The strategies the review team proposed for the horses included suitable stocking densities, and supplementary feed when necessary. Shelter should be provided when appropriate. Mares should be handled better and staff properly trained to minimize stress for the animals.
Mares, they said, should be checked for health and body condition before bleeding, and access to proper veterinary care should be ensured.
Blood collection should be limited to six liters per 1000kg of body weight every fortnight. Blood, they said, should be replaced with fluids if possible.
Abortions should not be induced, they said.
The full study team comprised Xavier Manteca Vilanova, from the Autonomous University of Barcelona in Spain; Nancy De Briyne, from the Federation of Veterinarians of Europe; Bonnie Beaver, from Texas A&M University; and Patricia Turner, from Charles River Laboratories in Massachusetts and the University of Guelph in Canada.
Horse Welfare During Equine Chorionic Gonadotropin (eCG) Production
Xavier Manteca Vilanova, Nancy De Briyne, Bonnie Beaver and Patricia V. Turner.
Animals 2019, 9, 1053; doi:10.3390/ani9121053