[Sue B]

Originally Posted by SalemsMom

It also depends on whether you have a easy keeper,they tend to founder easier,like someone else has said,you let them out on it a little at a time,I start with fifteen minutes on grass,twice dailey,and then let then do that for several weeks,then I increase their time by ten minutes longer,and go through the same process,intill they eventully are grazing 8 to ten hours a day,longer for hard kept horses,untill I work them getting on it 24/7. Horses kept on pasture all winter seem to do better when the grass comes up,but I do watch out for the easy keepers,or the horses that can gain weight just lookingat food.I also will throw hay out for them,in the beginning to,with a bluegrass,orchard and alfalfa mix.

Yes, this is a point....however, the trick is to determine what exactly is the issue. We have been following research that implicates the NSC (specifically sugars/fructrose) in grasses. But, if NSC is similar in grass and hay, then what else is adding to this issue?

And, yes, all the things you mentioned are good practices. Plain and simple changing from hay to grass and grass to ahy is similar to any other feed change and should be done gradually to prevent digestive upset.

Good discussion everyone!

[wyldterv]

Sue I"m not too versed in nitrate level either so have been googling, and I found this somewhat interesting...

10. I have heard that there is something in oats hay that is toxic to horses?
Answer: The most common cereal hay used for horses is oats hay (also known as greenfeed). Nitrate can be very high in some oats hays. High nitrate can be toxic to horses. Cattle are more susceptible to nitrate poisoning than horses however; precautions should be taken whenever a hay has more than 0.5% nitrate. To be safe, pregnant mares and young horses should not be fed nitrate- containing cereal hays. Oat hay can be tested for nitrate levels at a forage and soil testing laboratory.

and taken from this site: Nitrates in Hay

Nitrate poisoning should be a serious concern for livestock and horse owners in Eastern North Carolina.

Nitrates and Plants
The accumulation of nitrates in plants is a natural process. The plant gathers nitrogen through its root system and then stores it as nitrate in the stems. This nitrate is later converted to protein in the leaves.
What Causes High Nitrates in Hay?
Excessive applications or improper timing of commercial fertilizer or animal wastes can lead to excessive nitrate levels in grass pastures or the hay produced from it. High nitrate levels can also be caused by prolonged cloudy weather, droughts, or other plant stresses. Therefore, any forage can contain high nitrates under the right conditions, not just those applied with swine or poultry wastes! Also, forage that has been fertilized with animal waste can be high quality feed for cattle, sheep, goats, and horses. The only way to know the true quality of hay and assess the risk of toxicity is to sample it for chemical analysis.
How Do Nitrates Affect Livestock & Horses?
Nitrates interfere with an animal's ability to carry oxygen in the blood. Excessive nitrates in forages can cause reduced feed consumption and growth rates, lowered milk production and abortions. In severe instances, death will occur.
Signs of Nitrate Toxicity
Nitrate-poisoned animals will show symptoms of suffocation, including: labored breathing, lack of coordination, and blue mucous membranes. The most reliable symptom of nitrate toxicity is a chocolate brown coloration of the blood. Other signs include: diarrhea, frequent urination and frothing at the mouth.


Management Considerations for Use in Feeding Forages with Various Levels of Nitrate: %Nitrate Ion on a Dry Matter BasisPrecautions0.0 - 0.25Generally considered safe for all animals.0.25 - 0.50Slight Toxicity Risk: should not make up more than 50% of total intake for pregnant animals.0.50 - 1.00Moderate Toxicity Risk: do not feed to pregnant animals. Limit to less than 50% total intake for all other animals.1.00 - 1.50High Toxicity Risk: exercise extreme caution when feeding.1.50 and upSevere Toxicity Risk: do not feed to any animals

What Nitrate Levels are Safe for Horses?
Horses can tolerate up to 0.50% nitrate in their total dry matter diet. A "rule of thumb" is to select hay for horses that contains no more than 0.65% nitrate ion on a dry matter basis.
Can High-Nitrate Hay Be Fed to Any Animals?
Whether or not a particular forage will be safe to feed will depend upon what other materials are present in the animals' diet. The nitrate content of the hay is listed on the forage analysis report in percentage points. If it is higher than the recommended limits for the animals being fed, the hay or forage should not be fed without diluting the nitrate with other feedstuffs. In some instances, the level of nitrate in the forage may be high enough to prevent feeding it safely at all. While high nitrate levels are not desired in forages, protein levels are often quite a bit higher in high-nitrate forages than in low-nitrate forages. Therefore, high-nitrate forages can be used to the producer's advantage if he or she is aware of how to use them safely.

Originally Posted by Sue B

The big jumps are what I am interested in. Look at the nitrate/nitrite info. I'm not too familiar with this aspect of nutrition in hays and grass....maybe someone could explain some of it.

Nutrient - Hay vs Grass
% Dry Matter - 91.910 - 51.095
% Crude Protein - 10.489 - 15.258
Crude Fiber - 31.660 - 33.083
% Sugar - 10.722 - 10.267
% Starch - 2.501 - 3.259
% Non Structural Carbo. (NSC) - 13.128 - 12.541
% Crude Fat - 2.424 - 3.646
% Calcium - 0.523 - 0.566
% Phosphorus - 0.242 - 0.300
% Magnesium - 0.201 - 0.230
% Nitrate - - 0.060 -0.153
% Nitrates - 0.077 - 0.107
PPM Nitrate-Nitrogen - 174.302 - 240.708
Horse DE, Mcal/Lb. - 0.903 - 1.033
Horse TDN, % - 45.164 - 51.649

[Sue B]

Originally Posted by wyldterv

Sue I"m not too versed in nitrate level either so have been googling, and I found this somewhat interesting...

Thanks Wyldterv....so judging from this information....the levels of nitrates present in the info I provided would implicate nitrates as being a risk over NSC levels. However, at no time did any of the symptoms (which are most likely noted more in research cattle than horses) sound like they would result in laminitis/founder. And laminitis is as big an issue in cattle as it is in horses.

[wyldterv]

Originally Posted by Sue B

Thanks Wyldterv....so judging from this information....the levels of nitrates present in the info I provided would implicate nitrates as being a risk over NSC levels. However, at no time did any of the symptoms (which are most likely noted more in research cattle than horses) sound like they would result in laminitis/founder. And laminitis is as big an issue in cattle as it is in horses.

Yes more questions left then answered, I agree .... My SUSPICION is that there is some compound difference between NSC's in dried vegetable matter then in growing vegetable matter... While the NSC are the same in levels, perhaps there is some small chemical breakdown difference between cured hay and growing grass????

Perhaps the NCS combined with too much nitrates can compound together to bring on Lami/Founder???? I guess if we KNEW the answer we'd be writing papers and making more money then we do, lololol

[Sue B]

Ya right! LOL
There is a difference in that NSC levels fluctuate...in particular the fructans....in live plants. In dried material, they are stabilized...once the hay is cured. Prior to that the sugar levels are continuously being used until the plant stops its life cycles....which isn't when it is cut.

[3WishesDun]

I would guess it boils down to the "flushing of the grass" and the time of year/conditions under which the hay is cut.

I also wonder if the grass samples were taken from established stands of grass..... not overgrazed/stressed areas or not taken after first growth during the spring or after a freeze where the fructans would be very high.

There are so many variables.

[Sue B]

I know....it makes ya nuts doesn't it? It's just too many variables to get a good idea of what is going on. Also, there is no way to know what the grass averages were pulled from.

But, we got a little off topic....as I was more interested in how people determined how much fresh grass a horse needs vs hay? And is that dry matter vs as fed the real issue? It seems evident that a horse eating x amount of hay would need xx amount of hay to ingest an equivalently amount of dry matter...

[JBandRio]

Everything I've read says that the average 1000lb horse who's out 24x7 with grass will each grass for about 16-20 hours a day at a rate of about 4lb/hour, so between 64 and 80lb a grass a day. Since grass is roughly 25% dry matter, that's about 20lb of "hay" - right at the 2% body weight mark.

Katy Watts of www.safergrass.org has done huge studies on all types of grasses vs hays, taking samples from all over the country, various times of day, various times of year, and has found some surprising fluctuations in NSCs. She has even found that dormant Winter grass on a sunny day, even if very cold, can be amazingly high in sugars. Dormant doesn't meant dead - grass is still doing something to keep living.

So, because grass is 75% water, that alone can help prevent colic if a colic were to happen due to not enough water. Hay consumed has to pull water into the intestinal tract, so if there isn't enough water in the body, there's not enough to help keep the hay "slick", and it starts to stick.

[Sue B]

OMG....big error on my part....as I was typing that previous post...it suddenly dawned on me that the figures that I have for fresh grass are of the dry matter and not as fed! DUH.

[Sue B]

OK...no more general comments....so I'll bump this up for the late crowd with some eye opening info....

Here is the scenerio:
An 1100 lb. horse is on a maintenance diet. It spends the majority of it's time on pasture and is ridden occasionally on weekends. It's summer, and no hay or grain is fed in the barn. Pasture is the sole feed. It's lush and 20% dry matter (80% moisture). From the Dry Matter Intake Table, intake is estimated at 1.6% of body weight.

1. Calculate Lbs. of dry matter intake.
Lbs. dry matter intake = body weight x (%Dry Matter Intake/100)
Lbs. dry matter intake = 1100 x (1.6/100) = 17.6 Lbs.
2. Calculate Lbs. of pasture consumed, as fed.
Lbs. consumed, as fed = Lbs. Dry Matter Intake / (dry matter %/100)
Lbs. consumed, as fed = 17.6 / (20/100) = 88 Lbs.

Thus, to meet it's daily need for dry matter, this horse will need to consume 17.6 Lbs. of dry matter, which converts to 88 lbs. of pasture as fed.

Did anyone have any idea that a horse was eating this much grass when out at pasture all the time?
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This info and other good stuff can be found at Equi-Analytical Laboratories - Profiling Feed for Better Nutrition