Horses Undergo Pre-slaughter Stress, Study Confirms

That horses endure significant stress while waiting to be slaughtered has often been assumed. But a new study measuring stress hormone levels now confirms that theory, according to Italian researchers.

In the 45 minutes between removal from the holding area and stunning by captive bolt, horses' norepinephrine levels rose tenfold and epinephrine levels increased to 30 times the base rate, said Elisabetta Micera, PhD, researcher in the department of animal production in the Faculty of Veterinary Medicine at the University of Bari and lead author of the research. Plasma cortisol and beta-endorphins also increased, according to the study.

"This was the confirmation of an intuition," Micera said from her office in Italy, a country where approximately 200,000 horses are slaughtered for human consumption annually. "I could see the distress of the horses in the slaughterhouses. Horses are prey animals, and their adrenal medulla-sympathetic nervous system axes are dramatically stimulated by emotional and biological stress."

Micera's study included young male Russian draft horses that had been raised for meat production. Horses more conditioned to human handling might have different stress results, she said, but research would need to be carried out to determine those differences.

In any case, horses are social herd animals and are stressed by a disruption of the social order caused by chutes and lines, the study reported. Sights and smells at the facility also appear to evoke fear, resulting in raised stress hormone levels.

"The best method to reduce stress during the pre-slaughter phase is to enrich the waiting environment," Micera said. "Horses want to walk, and they need to be able to maneuver through sweeping, curved corrals in order to stay distracted."

Pre-slaughter stress could be improved through the use of humane handling systems, chutes, and corrals such as those designed by Temple Grandin, PhD, professor of animal science at Colorado State University, Micera said.

More information is available on PubMed.

About the Author

Christa Lesté-Lasserre, MA

Christa Lesté-Lasserre is a freelance writer based in France. A native of Dallas, Texas, Lesté-Lasserre grew up riding Quarter Horses, Appaloosas, and Shetland Ponies. She holds a master’s degree in English, specializing in creative writing, from the University of Mississippi in Oxford and earned a bachelor's in journalism and creative writing with a minor in sciences from Baylor University in Waco, Texas. She currently keeps her two Trakehners at home near Paris. Follow Lesté-Lasserre on Twitter @christalestelas.

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