Topic:Animal Physiology
Animal Physiology in horses encompasses the study of the biological functions and processes that occur within the equine body. This field examines how horses' systems, such as the respiratory, circulatory, digestive, and musculoskeletal systems, operate and interact to maintain homeostasis and support life. Research in equine physiology explores topics such as metabolic processes, thermoregulation, endocrine functions, and the physiological adaptations of horses to various environmental conditions and physical activities. This page gathers peer-reviewed research studies and scholarly articles that investigate the mechanisms, regulation, and implications of physiological processes in equine health and performance.
Standing horse posture: a longer stance is more stable. Horses stand for most of each day. Although they can use various leg configurations (postures), they usually stand with vertical legs. Why? We addressed this question with a 2D quasi-static model having three rigid parts: a trunk, massless fore-limbs and massless rear limbs, with hinges at the shoulders, hips, and hooves. The postural parameter we varied was ℓg, the distance between the hooves. For a given ℓg, statics finds an equilibrium configuration which, with no muscle stabilization (i.e. using minimal effort) is unstable. We assume a horse uses that configuration. To measure the neur...
Horses feel emotions when they watch positive and negative horse-human interactions in a video and transpose what they saw to real life. Animals can indirectly gather meaningful information about other individuals by eavesdropping on their third-party interactions. In particular, eavesdropping can be used to indirectly attribute a negative or positive valence to an individual and to adjust one's future behavior towards that individual. Few studies have focused on this ability in nonhuman animals, especially in nonprimate species. Here, we investigated this ability for the first time in domestic horses (Equus caballus) by projecting videos of positive and negative interactions between an unknown human experimenter (a "positive" ...
Grazing high and low: Can we detect horse altitudinal mobility using high-resolution isotope (δ13 C and δ15 N values) time series in tail hair? A case study in the Mongolian Altai. Carbon and nitrogen stable isotope time series performed in continuously growing tissues (hair, tooth enamel) are commonly used to reconstruct the dietary history of modern and ancient animals. Predicting the effects of altitudinal mobility on animal δ C and δ N values remains difficult as several variables such as temperature, water availability or soil type can contribute to the isotope composition. Modern references adapted to the region of interest are therefore essential. Methods: Between June 2015 and July 2018, six free-ranging domestic horses living in the Mongolian Altaï were fitte...
Changes of coat cover in primitive horses living on a reserve. Changes in the coat cover are important for mammalian thermoregulation. This is especially true where variable environmental conditions exist throughout the seasons. Coat cover shedding is the replacement of old coat hair with new hair. The process differs in various equids. The aim of the study was to examine the changes in the coat of primitive Polish Konik horses living on a reserve in southeast Poland (50.6319° N). The reserve is located in a temperate climate. The mean temperature is below 0°C in winter (December 8 to March 9) and over 15°C in summer (June 8 to September 8). Five adult...
Right-nostril use during sniffing at arousing stimuli produces higher cardiac activity in jumper horses. Lateralization in horses, Equus caballus, has been reported at both motor and sensory levels. Here we investigated left- and right-nostril use in 12 jumper horses freely sniffing different emotive stimuli. Results revealed that during sniffing at adrenaline and oestrus mare urine stimuli, horses showed a clear right-nostril bias while just a tendency in the use of the right nostril was observed during sniffing of other odours (food, cotton swab and repellent). Sniffing at adrenaline and urine odours was also accompanied by increasing cardiac activity and behavioural reactivity strengthening th...
Assessment of motor laterality in foals and young horses (Equus caballus) through an analysis of derailment at trot. The conflicting results regarding the study of motor laterality in horses may indicate that there does not exist a proper method to assess the degree and the direction of motor bias in these animals. Unfortunately, even less is known about the development of laterality in horses, and to what extent early manipulations can still exert their effects in adulthood. We propose a new method that can be easily applied at a very early age thus avoiding testing adult horses eventually biased by human handling and/or training. Forty-six horses (29 nine-month-old foals and 17 two-year old horses) were ha...
Luminance and chromatic discrimination in the horse (Equus caballus). Equine colour vision was measured under conditions that minimised the possibility of animals using brightness cues to make chromatic discriminations. In a two-stage study, we first obtained luminance discrimination functions for achromatic targets then tested for chromatic discrimination over a range of target luminances. Horses were trained on a two-choice discrimination task. The positive stimulus was varied in luminance and/or colour using neutral density and broad band colour filters. The negative stimulus appeared as a uniform grey. In the brightness discrimination task, the horses perfor...
Sound localization in large mammals: localization of complex sounds by horses. The idea that large mammals localize sounds more accurately than small mammals has been noted frequently and is usually explained by reference to their large interaural distance and the correspondingly broad binaural time (delta t) and spectral (delta fi) differences between their two ears. Sound-localization thresholds for single clicks and 100-ms noise bursts were determined for horses, and the magnitude of the binaural time (delta t) and spectral (delta fi) cues for sound direction were measured on a horse. Although horses have relatively large interaural distances and physically broad bina...
Response of horses to sweet, salty, sour and bitter solutions. The two-choice preference test was used to
characterize the test reactions of five immature
horses to sweet, salty, sour and bitter tasting
solutions. Sucrose was preferred ('>60% of total
fluid as test solution) to tap water by the foals at
concentrations ranging from 1.25 to 10 g/100 ml.
Concentrations above and below this range result-
ed in indifference (40 to 60% of fluid consumed as
test solution). The horses were indifferent to NaCI
until a concentration of.63 g/100 ml was reached.
At this level the mean response changed to
rejection (<40% of total fluid as test solution).
F...
On the watering of horses: a review. The literature published over the last 150 years provides confusing and often conflicting advice on the ideal way to water horses. Many of the problems associated with watering appear to be caused by either mismanagement or ignorance. An obvious way to prevent trouble is to provide adequate water at all times when a horse is at rest and to allow sufficient opportunity to drink while working.
[Cecal motricity and ceco-iliac transit in the horse]. Electrical spiking activity of the caecum is increased eight-fold and the rate of passage of digesta is increased four-fold when the volume of caecal contents is doubled. The role of caecal motility in regulating the volume of caecal contents is discussed.