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United States Department of Agriculture

Agricultural Research Service

Title: Effect of Added Sugar on Preference and Intake by Sheep of Hay Cut in the Morning Versus the Afternoon

Authors
item Burritt, E - UTAH STATE UNIVERSITY
item Mayland, Henry
item Provenza, F - UTAH STATE UNIVERSITY
item Miller, R - UTAH STATE UNIVERSITY
item Burns, Joseph

Submitted to: Applied Animal Behaviour Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 13, 2005
Publication Date: October 8, 2005
Citation: Burritt, E.A., Mayland, H.F., Provenza, F.D., Miller, R.L., Burns, J.C. 2005. Effect of added sugar on preference and intake by sheep of hay cut in the morning versus the afternoon. Applied Animal Behaviour Science. 94:245-254.

Interpretive Summary: Ruminants prefer hay cut in the afternoon to hay cut in the morning, presumably because hay cut in the afternoon contains higher concentrations of nonstructural carbohydrates (sugars) than hay cut in the morning. Lambs did prefer PM-cut to AM-cut alfalfa hay. Adding sufficient sugar to AM-cut to make up the difference in sugar with the PM-cut, still resulted in lambs preferring the PM-cut alfalfa in the short term, but on subsequent days they preferred the AM-cut to which sugar had been added. Our results indicate that preference for PM hay is likely related to increased levels of sugars such as glucose and sucrose, and that lambs learn about the postingestive benefits of exogenous sugars added to hay.

Technical Abstract: Ruminants prefer hay cut in the afternoon to hay cut in the morning, presumably because hay cut in the afternoon contains higher concentrations of nonstructural carbohydrates than hay cut in the morning. We determined if adding sugars - glucose and sucrose - to ground hay would account for differences in preference and affect intake of hay. Alfalfa hay cut either in the afternoon (PM) or the following morning (AM) was used in the trials. Glucose and sucrose were added to AM hay (AMS) to make its sugar content similar to PM hay. During the first trial, lambs received a choice of either: 1) AM and PM hay; 2) AMS and PM hay; or 3) AMS and AM hay. Lambs preferred PM to AMS or AM hay. We also studied how the concentration of added sugars affected preference for hay. Lambs received a choice of AM hay and AM hay with either 1, 2, 3, or 4% added sugar. On the first day of the trial, lambs ate similar amounts of each hay regardless of the amount of sugar added. By the end of the trial, lambs preferred hay with 2, 3 or 4% added sugar compared with AM hay without added sugar. During the intake trial, lambs ate similar amounts of AM, AM hay with added starch and sugar (AMSS), and PM hay. After the intake trial, a final preference trial determined that prolonged exposure to AMSS hay increased preference for AMSS hay compared with AM hay. Our results indicate that preference for PM hay is likely related to increased levels of sugars such as glucose and sucrose, and that lambs learn about the postingestive benefits of exogenous sugars added to hay.

Last Modified: 8/19/2014
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