Free Access Minerals

[Sir loin]

Last year I had a calf bed out and my vet blood tested the cow to show low calcium could have been the reason so we have gone for a free access mineral with a bit higher calcium level in it. How do you ensure every cow gets its daily requirement ?

 

[Werzle]

Law of averages

 

[Norfolk Hill Farmer]

Could you put limestone flour on to , or mixed in with the feed ?

 

[livestock 1]

Tip some on the feed

 

[Sir loin]

getting straw and haylage but falls through onto floor and maybe wasting some, Cattle have come in very fit this year so wasn't wanting to give any hard feed.

 

[M-J-G]

Providing extra calcium at calving will generally make things worse, which is why dry cow minerals are low Ca

Calving cows generally get low on calcium because the have been provided too much calcium during late pregnancy, which causes them to be "calcium lazy" leading them to being poor at utilizing the supply that they store in their bones.

 

[neilo]

Last year I had a calf bed out and my vet blood tested the cow to show low calcium could have been the reason so we have gone for a free access mineral with a bit higher calcium level in it. How do you ensure every cow gets its daily requirement ?

The mineral salesmen all say that they will only take what they need. On that basis, you can just provide it in a bucket somewhere and they will all take just the right amount......

Nah, I don’t believe it either, but most will have a lick of it and you probably won’t be far out.

 

[DaveGrohl]

Free access minerals are a total lottery in terms of how much any single animal will take to start with. The only mineral a cow will express an actual appetite for is salt. Cows can't regulate any of the other minerals through appetite anyway and what ends up happening is that they are just licking salt until they're satisfied. They can end up getting too much of some minerals to the point of toxicity, whilst other cows are barely touching the stuff. In short, you need to target specific minerals at the right time through a much more accurate method. Free access mins are a salesman's dream.

 

[Kiwi Pete]

This ^^^^^
Also the licks often cause obscenely high levels of minerals that aren't lacking; because the stock want the salt and/or molasses they mix it with to make a block/tub, copper toxicity etc is the end result

Safe to add limeflour to cow's diets post calving, perilous before calving as mentioned above; generally in NZ dairy systems mag C is added to water and mag oxide dusted onto springer's pasture, and limeflour added for the colostrum mob and milkers - mostly the deficiency down here is amplified by feeding stock on beet without supplementing minerals, as they are great scavengers of P+K .

 

[Norfolk Hill Farmer]

Providing extra calcium at calving will generally make things worse, which is why dry cow minerals are low Ca

Calving cows generally get low on calcium because the have been provided too much calcium during late pregnancy, which causes them to be "calcium lazy" leading them to being poor at utilizing the supply that they store in their bones.

Surely if they kept getting a regular supplement, they wouldn't need to utilise what's stored in there bones ?

 

[M-J-G]

Surely if they kept getting a regular supplement, they wouldn't need to utilise what's stored in there bones ?

With the surge in demand you cannot generally supply enough at the point of calving to keep them all going.
You might if you have them individually penned.

It's not something I've just made up. As I've already said, it is the reason why dry cow minerals are low Ca.

 

[Global ovine]

Surely if they kept getting a regular supplement, they wouldn't need to utilise what's stored in there bones ?

Mobilisation of calcium from the bones depends on blood level of magnesium. Mg has no storage organs in animals, therefore their blood Mg level reflects what has gone down the throat in the last 12 hrs.
Unfortunately many winter grown feeds are low in Mg (as it is not taken up by plants when soil temps are below 5 degrees C), so Mg dusting of silage is advised in late pregnancy. High K feeds and NaCl (salt blocks) accentuates low Mg blood levels.
All Ruminants have a huge Ca store in their bones, but it won't shift unless Mg is sufficiently available.

 

[DaveGrohl]

With the surge in demand you cannot generally supply enough at the point of calving to keep them all going.
You might if you have them individually penned.

It's not something I've just made up. As I've already said, it is the reason why dry cow minerals are low Ca.

Indeed, this is widely known these days. Feeding high Ca levels in the runup to calving is precisely the wrong thing to do. But, OP, giving high Ca immediately after calving helps, so by all means do that, several ways to do that, free access minerals still being the very worst option.

 

[Norfolk Hill Farmer]

Mobilisation of calcium from the bones depends on blood level of magnesium. Mg has no storage organs in animals, therefore their blood Mg level reflects what has gone down the throat in the last 12 hrs.
Unfortunately many winter grown feeds are low in Mg (as it is not taken up by plants when soil temps are below 5 degrees C), so Mg dusting of silage is advised in late pregnancy. High K feeds and NaCl (salt blocks) accentuates low Mg blood levels.
All Ruminants have a huge Ca store in their bones, but it won't shift unless Mg is sufficiently available.

I don't pretend to be hugely knowledgeable about this subject, but if there was plenty of calcium in the feed , would they need to mobilise it from their bones ?

 

[Kiwi Pete]

I don't pretend to be hugely knowledgeable about this subject, but if there was plenty of calcium in the feed , would they need to mobilise it from their bones ?

Generally, the answer is no; cows self-regulate how much Ca the rumen will absorb in this situation provided her Mg levels are sufficient

Hence the risk of high K feeds, such as fast-growing pasture that's received a lot of dairy effluent, or efficient scavengers such as beet.

In simple terms this excess K ties up the Mg available, combined with less rumen capacity when heavily pregnant it generally results in low blood Mg levels, hence many cows can present symptoms of "grass staggers/milk fever" concurrently.

 

[ShooTa]

@DaveGrohl the targetting - would it be best for a 10% blood sampling or from forage analysis?

 

[DaveGrohl]

@DaveGrohl the targetting - would it be best for a 10% blood sampling or from forage analysis?

I'm not quite sure what your asking given that I was responding to the OP's specific question about Ca around calving specifically. Blood testing and/or forage analysis wouldn't be particularly useful here as such. The cow pushing her calfbed out due to milkfever is telling you more than any blood sampling or forage analysis would anyway.

 

[Norfolk Hill Farmer]

Generally, the answer is no; cows self-regulate how much Ca the rumen will absorb in this situation provided her Mg levels are sufficientView attachment 845628
Hence the risk of high K feeds, such as fast-growing pasture that's received a lot of dairy effluent, or efficient scavengers such as beet.

In simple terms this excess K ties up the Mg available, combined with less rumen capacity when heavily pregnant it generally results in low blood Mg levels, hence many cows can present symptoms of "grass staggers/milk fever" concurrently.

If a powdered mineral containing mg was given at the same time, surely the cow would then be able to utilise the calcium?

 

[Kiwi Pete]

If a powdered mineral containing mg was given at the same time, surely the cow would then be able to utilise the calcium?

Yes, mag chloride is commonly used in water here.
Like Vit C in humans, that daily dose is required.

 

[Global ovine]

Read the following text to get an understanding of the dynamics of Ca in late pregnancy. Written by Dr. Rex Dolby, now retired head of Soil Science AgResearch NZ.
He wrote this for my ram clients and it has since been published in many pastoral countries. Its the same story for both sheep and cattle.

Many other similar articles by Rex are included in a publication "The Post Brexit Survival Guide" available from @easyram1 in both paper and electronic (email) forms, along with other "gems" regarding grazing and business management and sheep genetics by guess who.



PROLAPSE: WHAT CONTRIBUTES TO THIS:
The cause of prolapse of the uteruse (PU) is complex and cannot be put down to just one factor. We do, however,
know that a flock will suffer severe problems and by moving them they can lose this problem. This suggested that there must be a significant dietary influence and it is not just related to a flock constitution.

However, constitution will have an impact with problems greater in large pregnant ewes carrying multiple births and having poor muscle tone. Problems being related to increased pressure on the abdomen caused by excessive abdominal fat, a uterus full of lambs, a full rumen and a full bladder.

Large ewes carrying multiple lambs are the aim of high producing farmers. It is, therefore, often considered that this is a side effect of high producing ewes. However, why do some high producing operations have little problem with PU?

Nutrition of the Stock:
In high producing flocks we are putting stock under abnormal nutritional pressure. We expect more than that which is `natural’. Nutrition must therefore be very good and stock supplemented if natural intakes are not adequate.

In New Zealand (NZ) farming good nutrition means ensuring that the majority of the stock requirements are being met through the pasture and there is minimal supplementation. This means the need for quality pasture.

Pregnant ewes have a high demand for nutrients, protein and energy. Lack of any of these, or the exposure of stock to inclement conditions, can produce problems. Multi-birth ewes should be given special attention!

Metabolic Disease:
PU is a metabolic disease caused by the animal not being able to cope with the conditions it is under. It is related to the nutrients in the feed and to the ability of the stock to obtain nutrients from body stores. This means that factors that cause PU are complex and it cannot be fixed by supplementing ewes with just one mineral.

Calcium (Ca):
The sheep condition determines the tightness if the ligaments around the birth channel. Thus keeping stock fit is important but muscle tension is also related to Ca levels. There is thus evidence that Ca is involved. But Ca is stored in bone so stock should not suffer Ca deficiencies! Low Ca levels are thus related to the ability of stock to take Ca off of their bones.

Putting stock upon a restricted diet early in pregnancy is recommended. This is not only to reduce the size of the pregnant ewe but to also condition her to low intakes of Ca. By putting her under Ca stress early in pregnancy she will be more able to take needed Ca off of her bones in late pregnancy hence less likely to be Ca deficient at that time!

Alkaline Rumen:
The largest impact upon the ability of stock to take Ca off of their bones is the pH of the blood, which is directly related to the pH of the rumen: if the rumen is alkaline the blood is alkaline. An alkaline rumen can thus cause Ca deficiencies in late pregnancy due to the ewe not being able to take Ca from her bones. This could thus cause PU if the stock are susceptible.

The cause of an alkaline rumen is an excessive level of cations compared with the anions within the rumen (a cation to anion imbalance). The most influential elements are the cations potassium (K), sodium (salt)(Na), calcium (Ca)and magnesium (Mg) and the anions sulphate and chloride. High K and Na within the feed will make the rumen alkaline. High sulphur and chloride levels will make it acid.

Cold, Wet and Acid Soils:
Uptake of Ca and Mg by pastures is a metabolic process: to take these up the pasture must actively interact with the soil. This means that for adequate uptake by pastures soil conditions must be ideal. This means good oxygen levels, optimum soil temperatures and an optimum biological pH range!

For good uptake of Ca and Mg from poor draining soils it will, therefore, be important to ensure they are artificially drained and that they are well limed.

A well limed soil will also increase the level of clover in pastures with these high in Ca and Mg!

Potassium (K):
In contrast to Ca and Mg, uptake of K by pastures is not a metabolic process and uptake is highest when the soils are wet and cold! These conditions thus reduce uptake of Ca and Mg but elevate uptake of K. Thus if soils are wet and cold in late winter/early spring, pasture will be high in K, especially if soil K is high. In addition, uptake of K will be further increased by use of nitrogen (N) fertilisers at this time!

In turn, high soil K limits the uptake of Ca and Mg by plants and it also limits the ability of stock to take Ca and Mg from their rumen.

Thus high soil K can produce Ca and Mg deficiencies in stock especially when soils are cold and wet.

IN SUMMARY:
When stock are upon cold and wet soils that are high in potassium
Stock have an alkaline rumen that limits their ability to take Ca off of their bones.
There will be low levels of Ca and Mg in their feed.
Stock have reduced ability to extract Ca and Mg from their rumen
This situation is thus conducive to a severe Ca deficiency that will lower muscle tension and the tightness if the ligaments around the birth channel. They are, thus, susceptible to prolapse in late pregnancy!

If possible avoid placing ewes under these conditions in late winter/early spring. Also do not apply N or K at this time.

Sulphur (S):
In contrast to K, high pasture S will make the rumen acid. There is thus less likelihood of Ca deficiencies in ewes when the soil S is adequate to high over winter: an acid rumen will increase the ability of stock to take Ca off of their bones!

Adequate to high S is thus important over winter upon prolapse prone areas. This means that if you are upon free draining soils it will be important to use fertilisers containing fine elemental S to ensure that winter rains do not leach S out of the soils and produce S deficient feed in late winter. Use of fine elemental S fertilisers in autumn might be worth considering in prolapse prone areas!

Anabolic Salts:
Anabolic salts are used to control Ca deficiencies within stock and these salts include magnesium sulphate and causmag. These salts are used to make the rumen less alkaline. Dusting pastures with causmag will also reduce the uptake of K by pastures.

Conserved Feed:
Over winter stock are given large amounts of supplementary feed. It is therefore important this feed is not high in K and it contains adequate Ca, Mg and S. It is, therefore, very important that K is not applied to conserved feed paddocks prior to them being cut.

As with other pastures, the uptake of Ca and Mg will be improved through good drainage and the maintenance of a good soil pH. Mg fertiliser should also be applied with maintenance fertiliser and, if prolapse problems are severe, some Mg should be applied along with the N fertiliser used to boost the growth of the conserved feed and its protein levels.

In turn, if prolapse problems are severe, the conserved feed could be treated with causmag and molasses when being fed out to boost Mg, Ca and energy levels.

Salt:
The stocks requirement for salt is highest during pregnancy and lactation. This means that if stock require salt they should be supplied with salt blocks during this period. However, high salt (sodium) levels make the rumen alkaline, like K does, so dusting pastures with salt can cause Ca deficiencies and thus prolapse problems.

Pastures should thus not be dusted with salt in late pregnancy and if supplementing stock with salt, magnesium should be added to that salt.

By the sea, the impact of deposition of salt upon pastures and the high inputs of sulphate sulphur from sea breezes will often balance each other out. But in many situations, high inputs of salt and high soil K cause prolapse in ewes. In these cases there will be a need to treat pastures with fine elemental sulphur fertiliser to boost pasture S levels.

High Energy (Carbohydrate) Feeds Like Grain:
High carbohydrate feed breaks down in the rumen releasing carbon dioxide and makes the rumen acid: it can cause acidosis. Feeding grain, or other high carbohydrate feed, to ewes in late pregnancy can thus be used to neutralise an alkaline rumen thus reduce the chances of prolapse.

Clover & Lucerne:
Clover and Lucerne contain a high level of Ca so their use in conserved feed will increase its Ca level. However, as with other feeds, the value of this high Ca can be negated if K is also high: again K inputs must be controlled!


Summary:
As stated above, the factors causing prolapse are complex. There will be factors relating to the stock constitution but it is important when prone to prolapse to follow the rules below:

Only apply K fertiliser when it is definitely required.
Do not apply K to conserved feed paddocks prior to cutting: only apply it after cutting the feed to replace K taken out within the feed.
Do not apply N in late winter to pastures when soils are cold and wet.
Maintain a good soil pH through a regular liming program.
Use S fertiliser when it is needed.
Graze ewes in late pregnancy upon well drained warm soils: the use of sunny slopes will be appropriate.
Grow high quality pastures that are high in clover.
Dust pastures with causmag, treat feed with a causmag/molasses mix, and or supply stock with high magnesium sheep nuts if pastures are high in K.
Supply ewes with high energy feed or grain in late winter/early spring if prone to prolapse.
Add causmag to salt blocks if salt is needed.

The cause of prolapse is complex but if we can maintain a good quality pasture that is upon a soil that is not too high in K, has a good soil pH, is well drained and receives enough S fertiliser, we should be able to reduce problems. We may, however, also need to supplement stock with causmag and grain and to ensure that stock are not too fat!