24-h sheltering behaviour of individually kept horses during Swedish summer weather.
BACKGROUND
Provision of shelter for horses kept on summer pasture is rarely considered in welfare guidelines, perhaps because the benefits of shelter in warm conditions are poorly documented scientifically. For cattle, shade is a valued resource during summer and can mitigate the adverse effects of warm weather on well-being and performance. We found in a previous study that horses utilized shelters frequently in summer. A shelter with a roof and closed on three sides (shelter A) was preferred and can reduce insect pressure whereas a shelter with roof and open on three sides was not utilized. However, shelter A restricts the all-round view of a horse, which may be important for horses as flight animals. Therefore, we studied whether a shelter with roof, where only the upper half of the rear wall was closed (shelter B), would be utilized while maintaining insect protection properties and satisfying the horses' sense for security. A third shelter was offered with walls but no roof (shelter C) to evaluate whether the roof itself is an important feature from the horse's perspective. Eight Warmblood horses were tested each for 2 days, kept individually for 24 h in two paddocks with access to shelters A and B, or shelters A and C, respectively. Shelter use was recorded continuously during the night (1800-2400 h, 0200-0600 h) and the following day (0900-1600 h), and insect defensive behaviour (e.g., tail swish) in instantaneous scan samples at 5-min intervals during daytime.


RESULTS
Seven horses used both shelters A and B, but when given the choice between shelters A and C, shelter C was scarcely visited. There was no difference in duration of shelter use between night (105.8 ± 53.6 min) and day (100.8 ± 53.8, P = 0.829). Daytime shelter use had a significant effect on insect defensive behaviours (P = 0.027). The probability of performing these behaviours was lowest when horses used shelter A compared to being outside (P = 0.038).


CONCLUSIONS
Horses only utilized shelters with a roof whilst a shelter with roof and closed on three sides had the best potential to lower insect disturbance during daytime in summer.
Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 7011, 750 07, Uppsala, Sweden. elke.hartmann@slu.se.
Elke
E
Hartmann
Natural Resources Institute, University of Greenwich, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK. r.j.hopkins@greenwich.ac.uk.|Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 75007, Uppsala, Sweden. r.j.hopkins@greenwich.ac.uk.
Richard J
RJ
Hopkins
Unit of Applied Statistics and Mathematics, Department of Economics, Swedish University of Agricultural Sciences, Box 7013, 75007, Uppsala, Sweden. claudia.von.bromssen@slu.se.
Claudia
C
von Brömssen
Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, Box 7011, 750 07, Uppsala, Sweden. kristina.dahlborn@slu.se.
Kristina
K
Dahlborn
D000822:Animal Husbandry / Q000379:methods*; D000827:Animal Welfare; D000818:Animals; D001522:Behavior, Animal; D002940:Circadian Rhythm; D005260:Female; D006736:Horses / Q000502:physiology*; D006799:Housing, Animal; D007313:Insecta; D008297:Male; D012621:Seasons; D013548:Sweden; D014887:Weather