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Horses - Diet and Nutrition/high sugar levels in grass during mornings - reason


Hello ma'am. May I know why sugars levels are high in the grass pastures during mornings? Can I turn out my horses on the pastures in the evenings and collect them back before sunrise?

Hello Roberts,

Although I'm not a plant scientist, I would suggest that plants have the highest sugar levels after a day of sunlight and in fact have low sugar levels at dawn.  Plants make sugar through photosynthesis, using the day's sunlight as energy for sugar synthesis.  The longer plants are exposed to sunlight, the more sugar they produce.  The sugar is then converted to fiber overnight, leaving the plant with depleted sugar stores by early morning. Unless the plant is stressed overnight (i.e. extreme cold, drought) in which case it doesn't convert sugar to fiber at the same rate and may have higher residual sugar in the morning. Now keep in mind that the amount of photosynthesis that occurs, and the amount of sugar manufactured by the plant, varies by plant variety, by region, by season and according to the weather on any given day.

When you're dealing with high-sugar forage varieties early in the growing season where there's intense sunlight, the best time to turn horses out is from very early morning to mid-morning. But by understanding how plants respond to the day's conditions will let you make turnout decisions on a daily and seasonal basis.


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Corlena Patterson


I can help with any of your horse nutrition questions and concerns. I have been involved with horses for closing on 40 years, with a B.Sc in Animal Science and currently working on an M.Sc in Equine Science with the University of Edinburgh. I have owned my own feed store, consulted professionally as an equine nutritionist, and lectured in the fields of equine and dairy nutrition at the University level for 5 years. I have developed and currently market 'Ration-X', a ration formulation program for horses...designed for the everyday horse owner. I am happy to help in any way I can.


Experienced in developing and implementing feed programs for horses of all disciplines, creating custom horse supplements and managing inter-disciplinary equine facilities. Specialize in equine nutrition consulting.

The American Society of Equine Appraisers

'Stable Management' Handbook, Equine Canada.

M.Sc (Equine Science-current), B.Sc(Agr) Animal Science, Equine Sports Massage Therapy Certification, Farrier Certification, Equine Consultant Certification, Certified Equine Appraiser, Certified in Emergency Equine Rescue.

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