The significant role that housing conditions play in the occurrence of undesirable repetitive traits in horses has been highlighted in a recently published Italian study.
The traits, such as head weaving and crib-biting, which are known as stereotypies, were far more common among horses stabled alone than those living in groups on pasture.
The University of Parma study, involving 117 healthy saddle horses, chronicled a steadily increasing ratio of horses showing such traits across four housing conditions.
Stereotypies were most common among the 27 horses boxed individually without access outside and without contact with other horses, with 11 showing such traits.
Among the 30 horses boxed individually with the possibility of partial contact with other horses, six displayed stereotypies.
Among the 30 in group housing and with access to a large paddock, five displayed stereotypies.
The final category comprised 30 horses at pasture in groups of more than seven horses and with the possibility of green forage for the whole year. Just three showed stereotypies.
The horses in the study were enrolled from five different private stables in northern Italy and comprised 22 different breeds.
The most common stereotypy among them was crib-biting (21 out of 25 affected horses), followed by weaving (two horses) and circling (one).
Luca Molinari and his fellow researchers, writing in the journal Processes, noted the significant presence of horses showing stereotypical behaviour within the first category — boxed individually with no contact with other horses.
The finding suggests that the type of housing could significantly affect the manifestation of stereotypies, they said.
The main purpose of the study was to evaluate oxidative stress parameters in the horses in relation to their housing conditions, presence of stereotypies, age, sex and breed.
Oxidative stress plays an important role in the development of many horse diseases and it has been shown that housing has important implications for the psychophysical well-being of horses, the study team noted.
Oxidative stress was evaluated through a series of tests on plasma or serum samples.
The researchers found no significant differences in the parameters analyzed between the housing categories.
No significant differences in their redox status — that’s the balance between oxidants and antioxidants — were detected based on the presence or absence of stereotypies.
When the age was introduced as a selection parameter (either under or over 14) inside each housing category, statistical significance was observed for some of the stress markers considered.
Discussing their findings, Molinari and his colleagues said the analysis of oxidative stress parameters in relation to the presence or absence of stereotyped behaviors needs to be investigated further. No conclusive results have been reached at present, they said.
Oxidative stress seems to play an important role in the onset of many diseases. “Therefore, it is possible to hypothesize a role also in the determination of some stereotypies.
“However, the analysis of the data obtained did not reveal relevant changes of the redox status in relation to the management conditions taken into consideration.”
Some impact was seen but only for horses of different breeds and when the horses, within the different housing condition categories, were grouped on the basis of age.
Nevertheless, from what emerged from this study, there were no risk factors that negatively influenced the redox status related to the conditions in which the study horses were kept, they said.
The study team comprised Molinari, Giuseppina Basini, Roberto Ramoni, Simona Bussolati, Stefano Grolli, Simone Bertini and Fausto Quintavalla, all with the Department of Medical-Veterinary Sciences at the University of Parma; and Raffaella Aldigeri, with the Department of Medicine and Surgery.
Molinari, L.; Basini, G.; Ramoni, R.; Bussolati, S.; Aldigeri, R.; Grolli, S.; Bertini, S.; Quintavalla, F. Evaluation of Oxidative Stress Parameters in Healthy Saddle Horses in Relation to Housing Conditions, Presence of Stereotypies, Age, Sex and Breed. Processes 2020, 8, 1670.