title: The effect of a hay grid feeder on feed consumption and measurement of the gastric pH using an intragastric electrode device in horses: a preliminary report.
abstract: BACKGROUND
  Obesity and gastric ulceration are highly prevalent in horses. Management modifications for preventing squamous gastric ulceration include frequent feeding and free access to pasture; however, these practices may predispose horses to obesity.
  
  
  OBJECTIVE
  To compare the percentage of hay consumed, intragastric pH and horse activity between feeding from the ground and a hay grid feeder.
  
  
  METHODS
  Crossover experimental study.
  
  
  METHODS
  A pH electrode was inserted into the stomach to record the intragastric pH for 48 h. Horses received 1% of their body weight in grass hay twice a day. Horses were assigned to be fed from the ground or a commercial hay grid feeder for 24 h and then switched to the opposite protocol for an additional 24 h. Horses were continuously video-recorded and the percentage of time spent eating or drinking, walking or standing, and lying down were calculated. Two point data were compared by paired t test and pH over time was compared by repeated measures ANOVA.
  
  
  RESULTS
  Horses consumed significantly greater amounts of grass hay when fed on the ground compared with a hay grid feeder (n = 9; P<0.001). There were no significant differences between the groups for mean intragastric pH values (n = 6; P = 0.97), mean intragastric pH over time (n = 6; P = 0.45) the length of time the pH was below 4.0 (n = 6; P = 0.54), and the percentage of time horses spent eating or drinking (n = 9; P = 0.52), walking or standing (n = 9; P = 0.3), or lying down (n = 9; P = 0.4). Within each group horses spent more time eating during the day compared with the night (n = 9; hay grid feeder P = 0.003; ground feeding P = 0.007).
  
  
  CONCLUSIONS
  The hay grid feeder studied may be used to reduce the amount of hay ingested by horses without reducing the time horses spend eating.
authors.affiliation: The William R. Pritchard Veterinary Medical Teaching Hospital, University of California, Davis, USA.
authors.forename: F
authors.initials: F
authors.lastname: Aristizabal
authors.forename: J
authors.initials: J
authors.lastname: Nieto
authors.forename: S
authors.initials: S
authors.lastname: Yamout
authors.forename: J
authors.initials: J
authors.lastname: Snyder
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000818:Animals; D018592:Cross-Over Studies; D004435:Eating / Q000502:physiology*; D005247:Feeding Behavior; D005260:Female; D005745:Gastric Acidity Determination / Q000295:instrumentation / Q000662:veterinary*; D006736:Horses / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D008297:Male; D013270:Stomach / Q000502:physiology*; D014741:Video Recording
keywords: continuous recording; feeding net; gastric ulceration; horse; intragastric pH