How do I work out in kg what my horse eats whilst grazing?

[now_loves_mares]

I have a horse on box rest at the moment. Due to endless complications, we are trying to keep her off any hay/haylage. Yesterday I started hand grazing her, she is obviously being fed lots of fibre replacers, but I'm struggling to make it up to enough food, as I'm trying to feed small feeds, as she keeps colicing.

So my question is, if she has spent say 30 mins grazing, what % of her daily food intake would that be? She needs about 10-12kgs food a day, currently I am managing about 8 (she colicked 2 and 3 nights ago, so trying to not leave her with massive buckets of food). We got up at 1.30 and 3.30 last night to give her more readigrass, so we are prepared to do pretty much anything

Or is this a "how long is a piece of string" question?

 

[Lotty]

Found this:

As a guideline horses can eat 330g of grass per 100kg of bodyweight each hour in the first 3 hours of grazing followed by 100g per 100kg (BW) an hour afterwards.

 

[now_loves_mares]

Oh thanks. So if my rubbish maths (I'm an accountant, can only do sums on Excel ) are right, she's a 500kg- horse, so in the first hour she could eat 1.6kg-ish in that hour.

So if I can get her 3 hours a day, that should broadly add up to enough food, when coupled with her fibre replacers.

I presume the reason for the different quantities is due to the fact that horses will start to self-regulate after a period of time; but if I'm hand grazing her, the novelty factor should mean she eats at the upper end of the threshold. Today's evidence would prove this, as she is rarely stopping eating - hence the fact I'm trying to do it in lots of small bursts!

Of course I guess it is all a bit subjective anyway, given the quality of the grazing could mean that hour for hour the nutrional/calorific levels could vary significantly. But at least I'd feel I've tried to work out that she is getting enough food!

 

[happy_talk]

there are so many variables on this that makes it very difficult to quantify. ponies have been shown to adapt to restricted turn out and eat most of daily intake in 3 hrs turn out, despite ad lib haylage in stable for the rest of the day, just to complicate an already difficult measurement!
it also would depend on quality/length of the grass as well. grazing for 1 hr on short grass, intake will obviously be much less than long grass. in short, it is very difficult to know.
maybe ring a few feed advice helplines and see what numbers they give and any suggestions?