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Rumen distension and contraction influence feed preference by sheep
J J Villalba1, F D Provenza, R Stott
1Department of Wildland Resources, Utah State University, Logan 84322-5230, USA. juan.villalba@usu.edu
Journal of Animal Science
|September 16, 2008
Summary
Livestock learn to avoid feeds causing rumen distension (bloat) and prefer those associated with relief. This learning mechanism helps prevent bloat by guiding dietary choices.
Area of Science:
- Animal Science
- Ruminant Nutrition
- Animal Behavior
Background:
- Rumen distension, often caused by bloat, significantly limits feed intake in livestock.
- Ruminal dysfunction and excessive gas accumulation negatively impact feeding behavior.
- Understanding the learned responses to rumen distension is crucial for livestock management.
Purpose of the Study:
- To investigate if excessive rumen distension leads to feed aversions in lambs.
- To determine if lambs develop preferences for feeds associated with relief from rumen distension.
- To test the hypotheses that learned associations influence feed selection in response to ruminal pressure changes.
Main Methods:
- Commercial crossbred lambs were subjected to controlled rumen distension using inflatable balloons.
- Feed intake was measured during periods of distension and subsequent relief.
- Lambs were conditioned to associate specific novel feeds with either distension or recovery to assess learned preferences and aversions.
Main Results:
- Rumen distension significantly reduced feed intake in proportion to the distension magnitude.
- Relief from distension resulted in a compensatory increase in feed intake.
- Lambs developed strong aversions to feeds consumed during distension and preferred feeds consumed during recovery.
Conclusions:
- Rumen distension induces feed aversions, while recovery promotes feed preferences in lambs.
- These learned responses are critical for livestock to avoid bloat-inducing plants.
- The findings suggest that livestock can learn to prefer supplements or plants that alleviate bloat.
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