The relationship between cheek tooth occlusal morphology, apparent digestibility, and ingesta particle size reduction in horses.
OBJECTIVE
To investigate potential relationships between cheek tooth occlusal morphology, apparent feed digestibility, and the reduction in feed particle size that occurs during digestion in horses.


METHODS
Cross-sectional study.


METHODS
17 horses of various ages and breeds and either sex.


METHODS
Horses were fed 1 of 3 hay-based diets ad libitum for 14 days prior to euthanasia; nutrient analysis was performed on samples of each of the 3 diets. At the time of postmortem examination, the head was disarticulated, photographs were taken of the occlusal surfaces of the maxillary and mandibular cheek tooth arcades, and samples of stomach and small colon or rectum contents were collected for determination of apparent feed digestibility and particle size determination. An overall oral pathology score was assigned, and morphologic features of the occlusal surfaces of the cheek tooth arcades were determined.


RESULTS
Results of nutrient analyses did not differ among the 3 hay diets, and there was no significant difference in apparent feed digestibility among diets. Feed particle size differed significantly among the 3 diets, but stomach content and fecal particle sizes did not differ among diet groups. No significant correlations were identified between cheek tooth morphologic variables and feed digestibility, and fecal particle size was not significantly associated with oral pathology score.


CONCLUSIONS
Results did not provide any evidence of associations between cheek tooth morphologic variables, fecal particle size, and apparent digestibility in horses.
Carmalt
James L
JL
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N 5B4, Canada.
Allen
Andrew
A
D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D003430:Cross-Sectional Studies; D003766:Dental Occlusion; D003813:Dentistry / Q000379:methods / Q000662:veterinary; D004063:Digestion; D005243:Feces / Q000737:chemistry; D005260:Female; D006736:Horses / Q000378:metabolism / Q000502:physiology*; D008297:Male; D008409:Mastication / Q000502:physiology*; D010316:Particle Size; D013270:Stomach / Q000737:chemistry; D014730:Veterinary Medicine / Q000379:methods