Wood chewing by stabled horses: diurnal pattern and effects of exercise.

The research involves studying the wood-chewing habits of yearling horses, exploring the timing of these habits, and determining how exercise influences this behavior.

Research Design and Methodology

• The study used a sample of nine yearling horses that were held in individual stables for observation.
• The research was designed as a Latin square experiment. This type of experimental design is used to reduce the influence of other variables or factors not being primarily studied.
• The experiment was conducted over three separate two-week periods to account for variations in behavior over time.
• The horses were subjected to three different treatments: no exercise, exercise after their morning feeding, and exercise in the afternoon.

Diet and Exercise Routine

• The horses were fed a complete pelleted feed in the morning and a combination of pelleted feed and long-stemmed hay in the afternoon.
• The exercise routine included 45 minutes on a mechanical walker followed by 45 minutes in a paddock.
• Each horse’s stall was furnished with two untreated spruce boards which the horses had access to for wood chewing.

Data Collection and Analysis

• Wood chewing behavior was captured via video for 22 hours each period.
• The weight and volume of the wood boards were measured before and after each period to quantify the amount of wood chewed.
• The researchers also visually appraised the boards to record the extent of wood chewing.
• Consumption of trace mineralized salt, which might influence wood chewing behavior, was measured as well.
• Statistical analysis was performed with these measurements, first for 2-week periods and then for the full six-week trial.

Major Findings

• The researchers found that the primary wood-chewing activity occurred between 10:00 PM and 12:00 PM.
• When the entire 6 weeks were analyzed, all measures of wood chewing were correlated.
• When analysis was performed on 2-week values, videotape results were not correlated with volume or weight loss of boards, suggesting possible periodic variability.
• Horses engaged in more wood chewing when they were not exercised (511 seconds per day, on average).
• When horses engaged in exercise, wood-chewing rates dropped significantly, either in the morning (57 seconds per day) or afternoon (136 seconds per day).
• Salt intake was generally higher for horses that did not exercise, pointing towards possible compensatory behavior or nutrient deficiencies.