title: Heart rate and behavioural responses of crib-biting horses to two acute stressors.
abstract: The heart rate and behaviour of 14 adult saddle horses, eight crib-biters and six normal controls, were investigated. Initially, the relationship between crib-biting and heart rate was investigated while the horses were undisturbed. The horses were tested when restrained with a lip twitch, and assessed when they were exposed suddenly to the rapid inflation of a balloon. The heart rate of the crib-biters during crib-biting was lower than during other behaviours. The crib-biters had a higher overall mean heart rate (P<0.05) suggesting that they may have had a higher basal sympathetic activity. After the application of the twitch, all the horses had a transient increase in heart rate which returned to basal values more rapidly in the crib-biters. The crib-biters were less reactive to the lip twitch, five of the six investigated remaining calm, and after the release of the twitch, they spent more time nibbling (P<0.05) than the control horses. The crib-biters reacted more strongly to the inflation of the balloon (three of the six reacted), and after it had been inflated they spent more time walking in the box.
authors.affiliation: Instituto di Zootecnica Veterinaria, Università degli Studi di Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Minero
authors.forename: E
authors.initials: E
authors.lastname: Canali
authors.forename: V
authors.initials: V
authors.lastname: Ferrante
authors.forename: M
authors.initials: M
authors.lastname: Verga
authors.forename: F O
authors.initials: FO
authors.lastname: Odberg
mesh_terms: D000208:Acute Disease; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006734:Horse Diseases / Q000503:physiopathology*; D006736:Horses / Q000502:physiology* / Q000523:psychology; D008297:Male; D013239:Stereotyped Behavior / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology / Q000523:psychology / Q000662:veterinary*