Sugar / frosty grass confusion. Can anyone explain?

MDB

MDB

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Hello all,

Can someone explain the whole sugar / frosty grass thing to me. I tried to research on the tinternet but i still need clarity. i cannot get the lami app cos it isnt available 'in my country'.

From what i understand the plant (grass) uses energy from the sun during the day, through photosynthesis to make sugar. So the highest sugar levels are before sunset. At night, when no photosynthesis can take pace the plant uses the sugar as energy for growth and repair. However, on frosty nights / extreme cold the grass cannot do this and therefore the sugar remains stored all night.

Is that correct??? And if so, what happens to the excess sugar when the sun comes up. Does the plant simply start making more sugar? Or do the sugar levels subside? Does it make a difference if there are several frosty mornings in a row? ie an accumulation of sugar?

I am putting my mares out to graze after the sun is up and frost is melted. But I really dont know if that is right or wrong.

Help please :D :D

PS. they are grazing on a neighbours field in the day and I dont have the option of night turnout.
 
We put our stabled ones out on frosty grass, and the ones that live out, well, live out on it! I think as long as the ones you are turning out have some food/hay in their bellies they should be fine. I don't think its a huge problem imho.
 
Horses have evolved to deal with the frosty grass thing, as long as they are healthy then it shouldn't make any difference at all.

Maybe I have been fortunate, but I've been turning out first thing, rain, snow, frost, whatever for 40 years and never had a problem.
 
I was advised not to turn out on frosty grass if it can be avoided due to sugar levels, purely because I have two shetlands and like to be careful

I have to leave for work just after 8am so this isn't always possible. I just always make sure I put hay out if it is frosty, unfortunately though the big Welsh boy eats they hay but the Shetlands go off in search of grass-ice -cream!!
 
Thanks guys for your replies. I don't have any history for either of my mares. When they came to me their feet were terrible. Pretty large groovy event lines throughout their hooves. If they haven't had full blown laminitis in the past I would place a bet on them having sub clinical laminitis. Now their hooves are in reasonable shape, but one is a very good doer and I would like her to be lighter, so I just want to take all precautions, having spent the last year working hard to get their hooves healthy.

But moreover, I still would like to know what happens biologically to the high sugar in the grass on a frosty morning. Does it decline? Or does more sugar accumulate during the day as photosynthesis starts? Do sugar levels then progressively build up with consecutive frosty days? Anyone?
 
In colder weather the grass builds up sugars but due to the cold temps it doesn't grow so it is not used up, so it is stored in the stem making the grass more sugary. Grass will only use up its energy if it is over 4.5/5c.
 
My understanding of the frosty grass risk is that when nighttime temperatures drop to below 4ºc the fructans are converted to a type of glycol or antifreeze to preserve the grass and therefore these sugars are not used for respiration or growth.
It can actually increase the sugar levels by as much as 30%.

The danger factor comes in the digestive process in the hindgut, where bacteria breakdown fibre. The fructans are rapidly broken down and excessive amounts lead to an acidic environment and a change in the pH of the hindgut, this is detrimental to the bacteria which then die off.
This can lead to colic, diarrhoea and laminitis.

When its frosty its advisable to put out hay as an alternative.
 
If you have a laminitic/Cushings horse or pony then you need to know and understand the science.

With my old boy (Lammi/Cushings), my vet at that time advised me at all costs to avoid turning him out on a frosty morning when the sun was shining brightly. I can't explain the "science" bit any better than has already been done earlier here, but it IS something you need to know about if you have a horse/pony who suffers from Cushings and/or laminitis, or may be prone to it.

Any vet will explain it to you.
 
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