CONSEILS / TIPS AND TRICKS


Le préfané /enrubané. Meilleur que le foin ?
Haylage, is it better than hay ?
Avec l'aimable permission de Horsetalk, New Zealand ( www.horsetalk.co.nz )

 

Hay, the staple winter diet of domesticated horses for over a thousand years, has come in last in a university study exploring equine preferences for conserved forage.
Le foin, aliment d'hiver par excellence pour les chevaux depuis sûrement mille ans. Une université s'y intéresse et se demande si le cheval ne préférerait pas autre chose.

The winner in the carefully controlled study was baleage with a moisture content of 65 per cent, followed by grass which was baled and wrapped when drier (haylage), and then hay.
Le vainqueur de cette étude dûment controlée est le préfané à 65% d'humidité, suivi par le préfané à moindre taux d'humidité.

The research was carried out Dr Cecilia Müller and Dr Peter Udén, of the Department of Animal Nutrition and Management at the Swedish University of Agricultural Science in Uppsala.
L'étude a été menée par une université suédoise à Upsala.

The making of baleage and haylage involves wrapping grass to deprive it of oxygen, resulting in acidification of the forage (ensiling). The baleage was baled when the dry-matter content was 350g/kg (a moisture content of 65%).
Nos amis neo-zelandais ont diverses appellations pour le préfané : baleage=65%, haylage=30..45%. Pour l'étude, deux lots de préfané ont été sélectionnés. Le premier avait 45% de taux d'humidité et le deuxième 30%. Les ballots ont été emballlés dans les deux heures suivant la mise sous presse. Le foin (normal) a été récolté et sêché à 13% d'humidité

For the study, two lots of haylage were made and fed to the horses, each with a different moisture content at the time of baling. The first lot was made at 550g/kg (45 percent moisture content) and the last lot at 700g/kg (30 per cent). All bales were wrapped within two hours of baling.

The hay was baled at 870g/kg (13 per cent moisture content) and placed in a shed drier for nine days.

 


Terminology explained

The formal published report of this study refers to silage, haylage and hay.
The silage referred to in the study involved bales wrapped with a moisture content of 65 per cent, which New Zealanders would call baleage.
References to this wrapped silage have therefore been changed to baleage for this Horsetalk report.
In New Zealand, grass is normally baled for baleage with a moisture content between 30% and 60%.
The study also refers to haylage. The term haylage is less common in New Zealand, and in this study refers to two lots of grass baled and wrapped when drier - at moisture contents of 45 per cent and 30 per cent.
New Zealanders would, again, generally call this baleage, but we have retained the term haylage here for simplicity.
All bales used in the study were made with a high-density conventional baler.
The term silage is normally used in New Zealand to refer to chopped grass which is stored for ensiling in a large covered pit. This form of forage did not form part of the study.


All four feeds given to the horses were made from the same paddock and at the same level of grass maturity.  Les 4 lots ont été récoltés sur le même pré et au même niveau de pousse de l'herbe.

The researchers gave four horses the four forages once daily during four consecutive five-day experimental periods. Each sample contained 1kg of dry matter of each forage.
Les chercheurs ont donné à 4 chevaux les 4 fourrages une fois par jour durant 4 périodes-test de 5 jours consécutifs. Chaque ration contenait 1Kg de matière sêche pour chaque fourrage.

The horses were watched for two hours after the feed was given. Their first choice, eating time, and the percentage of each forage eaten was noted. The researchers also noted the number of times a horse tasted or smelt one of the offerings, but left it in favour of another.
On a étudié le comportement des chevaux pendant 2 heures après que la ration ait été donnée. A chaque fois on a noté le choix préférentiel, le temps pour manger et  le % de fourrage ingéré. Les chercheurs ont aussi noté le nombre de fois que le cheval sentait ou goûtait l'un des fourrages offerts mis le laissait en faveur d'un autre.

The study found that baleage was most popular, with the horses cleaning up 90 per cent of the offering, and taking, on average, 28.4 minutes a day to do so. It was the first choice 85 per cent of the time (72 out of 84 instances). It was never left in favour of either haylage or hay.
L'étude a montré que le 'baleage' était le pluspopulaire, les chevaux mangeant 90% de leur ration en 28.4min en moyenne. C'était le premier choix 85% du temps (72 fois sur 84 essais). Un autre fourrage ne fut jamais préféré au 'baleage'.

Hay was least favoured, and the offerings of hay were never completely consumed. The horses, on average, consumed only 23 per cent of the hay (based on dry matter) and ate it for only 6.8 minutes, on average.
Le foin était le moins apprécié. Il n'a jamais été consommé complètement. Seuls 23% ont été consommés et le mangeait durant seulement 6.8min en moyenne.

 

 
Haylage made with the higher moisture content (45%) was eaten, on average, for nearly 21 minutes, with 62% of it consumed. The haylage with 30% moisture content was eaten for 10.45 minutes, with only 34% of it consumed. Le préfané le plus humide (45%) est consommé à 62% en 21min. Celui à 30% est consommé en 10.45min mais seulement 34% est consommé. 

Drs Müller and Udén said the way in which forage is conserved clearly affects a horse's preference, but the reason for the high-moisture baleage preference has yet to be explained. Les Dr. Muller et Uden disent que la manière dont le préfané est conservé a une influence certaine sur l'appétence auprès du cheval mais ils n'expliquent pas pourquoi le préfané le plus humide plait plus au cheval.

The pair note that horse owners have sometimes claimed that baleage will not be eaten by their horses. However, they point out that published comparisons of voluntary intake have included forages with very different nutrient composition, and a strict comparison of preservation methods had not been done. Comparisons which have been done involved crops harvested at different stages of maturity, and at times involved comparisons of completely different crops altogether. Les deux chercheurs notent que les propriétaires ont parfaois affirmé que leurs chevaux ne mangeraient pas le 'baleage'. Par contre ils notent que les comparaisons ont été faites avec des fourrages de qualités diverses et que le mode de conservation n'a pas été étudié. Les comparaisons avaient été basées sur des préfané récoltés à des époques différentes de l'année et provenant de diverses pâtures.

 Hence the Swedish study used the same grass crop for the production of all forages used in the study. Par contre l'étude suédoise a utilisé exactement la même herbe, récoltée au même moment de l'année.

The four horses in the study comprised two warmblood riding horses (a mare and gelding), one Hanoverian mare and one crossbred Arabian/Warmblood gelding. They were aged from 4 to 23 years and weighed between 430 and 650kg. Les 4 chevaux étaient 2 demi-sang (jument et hongre), une jument hanovrienne et un hongre part-arabe. Ils étaient agés de 4 à 23 ans et pesaient de 430à 650kgs.

All horses had been on summer pasture for about three months before the beginning of the experiment, and remained on pasture during the experimental period, except when under observation around the forage, during which time they were stabled. Les chevaux étaient restés en pâture d'été durant 3 mois avant l'étude et sont restés en pâture durant la période de test, sauf durant les tests d'alimentation où ils étaient rentrés au box.

After each five-day experimental period, the horses had two days on pasture before the next experimental period began. They were always given the forage at the same time of the day, served in containers of the same size and colour. The order of the forage containers was changed each day. Entre chaque période de 5 jours, les chevaux avaient 2 jours de pâture avant le début de la période suivante. Ils ont toujours reçu leur fourrage au même moment et dans des containers exactement identiques et de même couleur. L'ordre de présentation des fourrages était changé à chaque fois.

The researchers also monitored the chemical composition and microbial content of the grass immediately before baling and from the bales as they were fed out. Le chercheurs ont aussi vérifié la composition chimique et microbienne de l'herbe avant la mise sous presse et juste avant de nourrir.

"Preference of horses for grass conserved as hay, haylage or silage", by Drs C.E. Müller, P. Udén, was published in Animal Feed Science and Technology (2007) 132, 66-78

 

Feeding baleage to horses - the ultimate guide / Nourrir au préfané - mode d'emploi

April 23, 2007

Balage is an increasingly popular winter feed for horses. It's nutritious and most horses enjoy it, but there are risks. Neil Clarkson reports on strategies to minimise them.
Le préfané devient de plus en plus populaire comme aliment d'hiver pour les chevaux et la plupart de nos équidés aiment cet aliment. Mais il y a des risques. Neil nous explique comment les minimiser
There's nothing like a disastrous hay season to get horse owners thinking about their options. Some think about balage - those big plastic-wrapped bales of grass that dot the countryside in increasing numbers as the summer progresses.
C'est après une mauvaise saison de récolte du foin que les propriétaires pensent à d'autres options. Il y en a  qui pensent de plus en plus au préfané (nos amis français appellent cela l'enrubannage). Il s'agit d'herbe coupée et emballée un certain temps après la coupe pour éviter les risques dûs à la pluie. Les propriétaires sont tentés d'essayer mais se rétractent après un essai infructueux.

While some contractors now offer wrapped small bales, most is made in rounds, or big or medium squares. A horse owner will need to pay a contractor to cart them in. Even if you have a tractor, you will need a special clamp to pick them up without rupturing the plastic.
Bien que certaines entreprises agricoles puissent emballer de petites balles, le conditionnement principal se fait en grosses balles, soit rondes, soit carrées. Mêm si vous disposez d'un tracteur il vous faudra un équipement spécial pour ne pas endommager le plastique.

They can be stored outside, which will appeal to many, but once cut open they must be fed out within a few days. Unless you have a lot of hungry horses, or some cattle on your property, you may not get through a bale before it spoils.
Les ballots peuvent être stockés à l'extérieur, mais une fois ouverts, il doivent être consommés en quelques jours sinon la matière pourrit.

 


Balage Pros and Cons

Pros
• Your crop is far less likely to be ruined by rain.
• You can store it outside.
• It retains more food value than hay.
• It will help you achieve the rule of thumb of providing two-thirds of your horse's diet in forage feed.

Cons
• It's more costly than hay.
• Bales will be at least twice as heavy as their hay equivalents.
• Specialist gear is needed to move big bales, or you need to employ a contractor to do it.
• You need to check regularly for holes and repair them.
• Once open, bales need to be fed out within a few days.
• Horses can contract botulism from poor quality balage.
• Storage life can vary from bale to bale.
 


Unless you have specialist feeding-out gear, most horse owners will find medium squares the most convenient to feed by hand, as you can peel off the balage a slab at a time. 
A moins de disposer du matériel adéquat, les propriétaires de chevaux préfèrent les balles carrées de taille réduite pour autant qu'elles soient disponible dans le coin. On peut dans ce cas prendre des tranches plus facilement.

Balage is also more costly, but you have to weigh that against the higher food value when compared to hay.
Le préfané coûte plus cher à cause de l'emballage plastique, mais il faut savoir que le taux en matière sêche est plus élevé que dans le foin.

Like hay, things can go wrong. There are also risks in feeding it to horses - mostly the danger of botulism poisoning, which we will consider later.
Mais il peut y avoir des soucis ou des risques à nourrir les chevaux avec du préfané. Le principal est le botulisme. ON le verra plus loin dans cet article.

What is balage?

Balage, silage, and haylage are names for the same basic product: ensiled grass. It doesn't matter whether the grass is going into a massive silage pit or a plastic-wrapped bale - the process is the same.
The grass is baled when much greener than hay. Hay is typically baled with a moisture content between 15% and 17%. Ensiled grass is typically between 30% and 60%, with the most stable balage usually made in the higher half of that range.
L'herbe est emballée alors qu'elle est encore humide. Le foin est généralement mis en ballots lorsque le taux d'humidité atteint 15 à 17%. Pour le préfané, on parle de 30 à 60% d'humidité. Le meilleur compromis est de l'ordre de 45%.

The grass may only be cut for a day or even less before the balers arrive. Souvent après seulement un jour, la matière est prête à être emballée.

The grass needs to be good quality with a high sugar content. Coarse, stemmy grass will not only make inferior balage, it is also more likely to puncture the plastic wrap.
Il faut que l'herbe soit de bonne qualité avec un taux élevé de sucres. L'herbe de mauvaise qualité ne va pas seulement produire un mauvais préfané mais risque aussi de percer le plastique de protection.

The contractor needs to produce a good tight bale with as little air in it as possible. Loose bales are unlikely to make good balage. (When silage is being made, a digger will trundle backwards and forwards over the grass for hours, compacting the heap as much as possible.)
La société devra produire un ballot compact avec le minimum d'air.

 


Moisture content is critical

Correct moisture content is considered one of the most critical elements in successfully making balage, along with high sugar content. The usual range is 30% to 60% moisture, with the most stable balage usually being made in the higher half of that range. If it's baled much above 60%, conditions tend to swing in favour of the clostridial bacteria.

Baling grass that is too dry has its problems, too. A drier bale is likely to undergo too much damaging aerobic activity before anaerobic fermentation begins. It is also less likely to drop below the desired pH of 5.0, giving clostridial bacteria yet another opportunity to multiply.

 


 

Soon after, the plastic wrap goes on, sealing the grass from the outside world. The ensiling process is about to begin. A combination of natural plant respiration and the action of aerobic bacteria begin to heat the bale, much as you would expect in a compost heap. But aerobic bacteria need air and, on a warm day, a wrapped bale can be all out of oxygen in 30 minutes. However, if conditions are cooler, or there is too much air in the bale, this process can take hours, sometimes even days. 
Dès que le plastique a été posé, le processus d'ensilage commence. La respiration naturelle de la plante and l'action aérobique bactérienne vont faire chauffer le ballot, plus que dans un compost. Mais le processus nécessite de l'oxygène et s'il fait chaud, un ballot aura consommé tout l'oxygène emprisonné en 30 minutes. S'il fait froid ou que trop d'air a été emprisonné , le processus va durer des heures, parfois des jours

A well-compacted bale may heat as little as 3degC before it runs out of air. Grass baled when drier is likely to have more air trapped in it, and the heating process can continue too long. Once temperatures of 40degC or more are reached, the grass will suffer heat damage and blacken, sometimes costing more than half the available protein.
Un ballot bien compacté va seulement chauffer de 3°C avant que l'oxygène ne soit épuisé. Si l'herbe est trop sêche, il y aura trop d'air à l'intérieur et le processus va durer trop longtemps et la température va trop s'élever. A plus de 40°C, l'herbe va subir les dommages de la chaleur et noircir et perdre de sa valeur nutritive.

Generally, the quicker this aerobic phase is over, the better, because the goodies you want to feed out to your horses are being used up. Bacteria are turning useful water-soluble sugars into carbon dioxide and water, with heat being a major byproduct.
Généralement, plus vite va le processus aérobique, mieux c'est. Si le processus dure trop longtemps, les sucres solubles se dégradent.

Once the oxygen is gone, this aerobic heating phase will end. However, waiting in the wings are anaerobic bacteria, which function without the need for oxygen. They multiply rapidly and begin to ferment the grass, turning the plant sugars into organic acids - mainly lactic and acetic acid. As this continues, the bale becomes increasingly acidic.
Une fois que l'oxygène a été consommé, cette phase d'échauffement aérobique se termine. Cependant les bactéries anaérobiques n'ont pas besoin d'oxygène et se multiplient rapidement pour faire fermenter l'herbe en transformant les sucres en acides organiques. Le ballot devient acide.

Once it reaches a pH of about 3.8 to 5.0, the anaerobic bacteria find the going too tough and the fermentation process grinds to a halt. The bale has reached a stable state, ready to ride out the months until it is fed out. All should remain well unless the bale is punctured and oxygen penetrates.
Une fois qu'il atteint un pH de 3.5 à 5, le processus s'interrompt. Le ballot a atteint un état stable et peut se conserver durant des mois. Tout se passera bien à moins que le plastique ne soit percé et que l'oxygène ne pénêtre dans le ballot.

 


Hints for making good balage

These measures will not only improve balage quality, but reduce the risk of spoilage.

 

 
Using quality grass with a high sugar content increases the chances of making good balage.
 

 

  • Use grass before it's too mature and stalky. Younger grass will make much better balage. Poor quality grass will always make poor quality balage.
     
  • Cut the grass later in the day, when the sugar content will be higher.
     
  • Cut only when you're confident you can get it baled and wrapped before it rains.
     
  • If your cut grass does get rained on, tell the contractor to use an additive which will help the fermentation.
     
  • Do what some farmers do: pay extra to have inoculant applied every time you make balage.
     
  • Wrap bales as soon as possible. Asking for extra layers of plastic will add about $3 a bale. It is good insurance against holes and your bales are likely to keep longer.
     
  • Do not make balage from a paddock contaminated with dung, especially one fertilised with poultry manure.
  • Move bales as soon as possible after wrapping to their final resting place, and do not move them again.
     
  • Check bales regularly for holes and tape them up.
     
  • Get the moisture content right at baling to increase your chances of good balage. Wetter balage not only runs an increased risk of clostridial spoilage, it can also be damaged through freezing. If the grass is getting too dry, make hay.
     
  • Never use a tedder unless it allows you to get it baled before rain strikes. Tedding usually shouldn't be necessary - the "fluffing up" that results will only serve to put more air into the finished bale, which you don't want.
     
  • Ensure the rake doesn't contact the ground, stirring up dust which can put clostridial bacteria on the grass.
     
  • Avoid baling small-animal carcasses with the grass.
     
  • Store balage with some shelter from the sun. Fermentation is at its best in the range of 15 to 25degC. Higher temperatures favour clostridial bacteria, so avoid storing balage where its temperature is likely to exceed 30deg.
     
  • The more even the temperature during the fermentation and storage, the better.
     
  • Don't stack the bales.
     
  • When feeding a bale out over several days, close the plastic back over the opening to keep air out as much as possible.
     
  • It's important to have enough sugar in the bale to drive the fermentation and drop the pH to a level that will result in stability. If the bale runs out of steam at a pH above 5.0, undesirable clostridial bacteria can take hold. Fermentation will be incomplete and the bale will be less stable, and its life much shorter. 
    Il est important d'avoir un taux en sucres suffisant pour produire le fermentation et faire baisser le pH suffisamment. Si le pH ne descend pas sous 5.0, des bactéries clostridial peuvent subsister. La fermentation sera incomplète  et le ballot se conservera moins longtemps.

    This is why it's important to use grass when it's younger and still has high sugar levels. Some contractors will not cut the grass until after lunch. The longer the sun is on the grass, the higher its sugar content.
    C'est pour cette raison qu'il est important d'utiliser de l'herbe jeune avec un taux élevé en sucres. Certains contractants ne vont pas vouoir faucher l'herbe avant le déjeuner, car plus le soleil est élevé, plus le taux en sucres suit le mouvement.

    While the ultimate pH achieved in your balage is important, the speed at which it gets there is also critical. The longer the bale stays outside the desired pH range, the more likely that bad bacteria can take hold.
    OK, le pH final est important mais aussi le temps qu'il met à arriver à cette norme. Plus le ballot reste en dessous du pH désiré, plus longtemps les bactéries nuisibles vont subsister.

    If all goes well, your wrapped bales should dip below pH 5.0 in a few days and, preferably, under a week. Fermentation will continue slowly for a few more weeks, but the critical pH has been reached.
    Si tout va bien, vos ballots descendront sous le pH 5.0 en quelques jours et de préférence en moins d'une semaine. La fermentation va continuer doucement durant encore quelques semaines mais le pH critique a été atteint.

    There are ways a contractor can help things along. If they use a baler that chops the grass as it is fed into the baling chamber, this will speed the process. They can also spray the cut grass with an inoculant, containing good bacteria and enzymes, or an acid-based preservative. Some would consider one of these options essential for any cut grass that has been rained on, or for grass that is drier than desirable.
    Il y a diverses manières pour accélérer les choses. Si l'herbe est re-coupée au moment de l'enrubannage, cela va accélérer le processus. Ils peuvent aussi vaporiser un inoculant avec des bactéries et des enzymes adéquats ou un conservateur acide. On considère cela comme indispensable lorsqu'il y a eu pluie ou si l'herbe est trop sêche.

    The risk with horses

    Balage is a nutritious feed that many horses enjoy. Many hundreds of horse owners swear by it, saying their horses do well on it over the winter months.
    Beaucoup de chevaux adorent le préfané. De plus en plus de propriétaires ne jurent que par le préfané, surtout en hiver.

    However, it is important to recognise the risks and how to minimise them. Cependant il est important de connaitre les risques et de les minimiser.

    The biggest worry is botulism. Horses are very susceptible to botulism poisoning, which usually proves fatal. Le souci principal est le botulisme. Les chevaux y sont très sensibles et l'issue est souvent fatale.

    Botulism poisoning causes progressive paralysis. Muscle trembling will be apparent and the horse will lie down often. If you pull their tongue out, they will have difficulty pulling it back. They can only eat with difficulty and death normally results from breathing paralysis, or complications from the amount of time spent lying down.
    Le butulisme provoque la paralysie. Le smuscles se mettent à trembler et le cheval va souvent se coucher. Si vous retirer la langue, le cheval aura difficile de la remettre en bouche. Il ne peut manger qu'avec difficulté et la mort survient par la paralysie du système respiratoire ou des complications à force de se coucher.

    Poisoning results from the toxin produced by Clostridium botulinum. There are seven known kinds, each producing a slightly different botulin toxin. One variety is found in poultry manure; another thrives in the carcasses of dead animals. One is even found in fish.
    L'empoisonnement provient de la toxine produite par le 'Clostridium botulinum'. Diverses variétés existent. L'une provient de la fiente de volaille; une autre des cadavres d'animaux; une autre des poissons.

     

     
    Several kinds are common in soil and can gain a foothold in a bale if the ensiling process fails to drop the pH below 5.0.
    Plusieurs variétés de toxines sont communes dans le sol et peuvent être présente dans le préfané si le pH n'a pas descendu sous la valeur de 5.0. 

    The faster the bale reaches a pH of 5.0 or less, the less chance that clostridial organisms can take hold. Higher pH levels can also provide a suitable environment for listeria.
    Plus vite le ballot atteint un pH de 5.0, plus on réduit le risque de toxines.

    Bales made with a moisture content greater than 60 per cent also stand a greater chance of becoming badly affected by Clostridium botulinum.
    Les ballots avec un taux d'humidité supérieur à 60% ont aussi moins de chances d'être affecté par le botulisme.

    Clostridial spoilage arises from the production of butyric acid. The balage will be sour and foul smelling, often like ammonia. You are likely to find evidence of slime moulds. Never feed it out. In fact, do not feed out any mouldy balage, even if it still has that distinctive balage smell.
    Si le ballot sent mauvais, souvent une odeur d'ammoniaque , ne pas l'utilser. Si le foin est moisi ne pas l'utiliser même si l'odeur reste typique du préfané.

    The issue, as with most feeds for horses, comes down to quality. Most feeds have their dark side: Substandard hay can deliver dangerous moulds and trigger hay colic. Moist grain can carry dangerous mycotoxins. Badly made balage brings with it the risk of botulism poisoning.


    Dealing with and preventing holes

    There's little point in making balage unless you're going to be diligent about keeping it sealed up. Farming stores sell tape for the purpose, so get some before the bales are made. Use the tape to seal up holes as soon as you find them.

     

  • Set aside an area for storing the bales where no stalky material or sharp stones are likely to puncture the bottom of the bales.
     
  • Check them over carefully for holes once wrapped, and seal them up with tape. Check again once they're moved off the paddock.
     
  • Stock will chew through balage plastic so erect temporary fencing if necessary to keep animals out.
     
  • Birds can puncture bales with their talons and beaks. Some farmers store their balage close to busier areas so birds don't get free rein.
     
  • Heavier bales are more likely to be damaged when being moved.
     
  • Pay the contractor to put extra wrap on each bale. More plastic means less chance of holes. It has been suggested that two extra layers is as good as using inoculant.
     
  • Keep children and pets from climbing on the bales.
     
  • Don't store the bales where you know porina to be a problem.
  •  

    Provided the balage is of high quality, evidence would suggest the risk is low, but each horse owner will have to make their own call. Like any feed change, it needs to be introduced gradually to a horse's diet.
    Si le préfané est de bonen qualité, le risque est très limité. Cependant le passage au préfané doit se faire graduellement.

    Dr Simone Hoskin, senior lecturer in ruminant and equine nutrition at Massey University's Institute of Veterinary, Animal and Biomedical Sciences, believes pit silage is more risky than balage because of its generally higher moisture content.
    Dr Simone Hoskin croit que le silo est plus dangereux que le ballot, car ce dernier a généralement un taux d'humidité plus élevé.

    "Wrapped silage (balage) can be a great feed for horses and can be very cost effective," she says, "although once a bale has been opened it should be used within a few days unless it is very cold or snowy weather, in which case it can be fine for up to 10 days - otherwise you can get secondary fermentation."
    "Le préfané est une bonne alternative pour les chevaux et à un coût intéressant". "une fois qu'un ballot est ouvert, il doit être consommé dans les quelques jours sauf s'il fait très froid, auquel cas il peut durer 10 jours. Sinon, une seconde fermentation aura lieu.

    Dr Hoskin considers the risk of botulism poisoning low, provided the balage is of good quality.

    It is hard to escape the conclusion that New Zealand appears to be a low-risk area for botulism poisoning in stock. There have been no recorded cases of it in any species at Massey University in at least 10 years. It is known in birds, but there do not appear to have been any cases reported in cattle in this country. Even if cattle cases have come to light here, they would certainly rate as extremely rare.
    La Nouvelle Zélande a beuacoup moins de risques de botulisme que d'autres contrées. Il n'y a pas eu de cas durant les 10 dernières années.

    All this will no doubt provide considerable comfort to horse owners feeding balage, although it should be noted that horses are more susceptible to botulism than cattle.

    Overseas, livestock have not been so lucky. Feed-related outbreaks of botulism have not only been linked to silage and balage - big-bale lucerne hay and oaten chaff have also been a source. This shows that any spoiled feed (not just balage) could potentially carry a risk of botulism and should never be fed out.
    Ce n'est pas le cas dans d'autres pays où des cas de botulisme ont été rapportés, pas seulement à cause du préfané mais aussi à cause de luzerne ou de paille d'avoine.

    The risk for horses may be low, but remember the golden rule: never feed spoiled, mouldy, or poor quality balage to horses.

     


    What can go wrong?

     

  • The cut grass can be rained on. This leaches sugar from the grass and can result in poor balage. Rain can also splash clostridial bacteria from the soil on to the grass, which can cause bad fermentation.

     

  • The bale plastic can be punctured, either while being transported, by birds, vermin, porina moths emerging from the ground beneath the bales, or by stalky material poking through the plastic. (see "How to prevent holes").

     

  • The wrong kinds of bacteria can take hold, ruining the bale and risking botulism poisoning in horses if fed out.

     

  • The grass may not have enough sugar to fully ferment, resulting in an unstable bale and increasing the chances of spoilage.
     
  • Test for quality 

    Balage being bought should be tested for quality and the price should reflect the quality, says Massey University equine nutritionist Dr Simone Hoskin.

    Most major suppliers get their product tested, she says. "If they haven't, you are quite within your rights to ask for it to be tested, or get it tested yourself."

    A fresh 500g sample (preferably from the centre of a bale) can be sent by courier in a sealed plastic bag to a variety of labs for analysis, including the Massey University Nutrition Laboratory.

    Horse owners otherwise risk paying too much for poor quality feed, she says.

    Le préfané devrait être testé en qualité et le prix devrait être lié à la qualité. La plupart des gros fabricants testent leurs produits, mais s'ils ne l'ont pas été, vous avez le droit de le demander ou le faire vous même en envoyant un échantillon à un labo spécialisé, de préférence venant du centre du ballot.

    Keep your friends

    If you're feeding balage out by hand, have a dedicated set of clothing for the task, including gloves. The smell of balage is quite invasive, and not everyone will enjoy Eau de Silage. It's one of those smells that keeps on giving!
    Portez des gants lorsque vous manipulez du préfané pour éviter d'incommoder vos proches avec ces odeur insistante.

    Watch for the skitters

    Balage can trigger loose bowel movements in some horses, probably through finding the feed too rich or acidic. The problem is usually overcome by providing hay with the balage.
    Le préfané peut accélérer le transit chez certains chevaux. En incorporant du foin, le problème se règle.

    What about a vaccine?

    Veterinary reports in the United States have suggested vaccinating against botulism if feeding balage to horses. However, the inoculation requires two or three shots (with annual boosters) and is certainly not foolproof, mainly because it doesn't cover all varieties of the bacterium. Undesirable side-effects have also been reported. One vet suggested it was not a decision to take lightly. The vaccine does not appear to be available in New Zealand.
    Des études vétérinaires aux USA suggèrent de vacciner contre le botulisme. La vaccination requiert deux à trois injections et un rappel annuel et n'est pas efficace sur toutes les toxines. Il y a aussi des effets secondaires. Le vaccin n'est pas disponible en NZ.

     

     

     

    Mouiller le foin... durée ?/ Soaking hay... how long

    September 11, 2007

    Soaking hay before feeding it to horses is common practice to help reduce respiratory disease. But does it really help cut the amount of dust inhaled by the horse? And for how long should the hay be soaked for the optimum effect?
    On mouille généralement le foin lorsque l'on a des soucis respiratoires. Mais est-ce que cela sert vraiment à réduire la poussière inhalée par le cheval? Et quelle est la durée optimale de trempage ?

    A recent study at the University of Edinburgh looked at the effect of soaking hay on the dust levels in the stable. Rather than look at the dust concentration within the stable as a whole, Dr Jenny Clements and Dr Scott Pirie confined their measurements to the breathing zone - the region around the horse's nostrils.
    Une étude récente à l'Université de Edinbourg a fait une étude récemment. Plutôt que de calculer la qualtité de poussières dans l'écurie, les scientifiques se sont penchés sur la poussière autour des naseaux du cheval.

    Although all dust is unpleasant, from the point of view of respiratory disease, the important dust is that which is small enough to reach the small airways where it may cause inflammation. This is known as respirable dust. These dust particles are generally considered to be 0.5 - 5 mm in diameter.
    Bien que la poussière en soi est désagréable, du point de vue des maladies respiratoires, on s'attache surtout à la poussière fine qui cause l'inflammation, celle dont les particules sont inférieures à 0.5 mm.

    A battery operated sampling device attached to the horse's head collar allowed the respirable dust concentration (RDC) to be measured within the air that the horse was actually breathing.
    On a ici mesuré avec un appareillage attaché au cou du cheval la concentration en poussières dans l'air respiré par le cheval.

    They found that simply immersing the hay in a bucket of water more than halved the average and maximum RDC in the horse's breathing zone. Soaking the hay overnight (16 hours) did result in lower RDC but the difference was not significant.
    On s'est aperçu que le simple fait de tremper le foin juste avant de nourrir divisait par deux les poussières, mais que le fait de laisser tremper pendant 16 heures neproduisait pas de différence significative.

    Clements and Pirie conclude that "there is probably little advantage in terms of equine respiratory health in soaking hay for 16 hours compared with simple immersion." La conclusion est que le trempage du foin pendant une durée prolongée n'a pas vraiment d'avantage par rapport à une simple immersion.

    It is often thought that little can be done to improve the respiratory environment when two stables share the same airspace. Now it seems that this may not be correct. In a further study, Clements and Pirie showed that improving the management of one stable had beneficial effects on the neighbouring stable.
    On pense souvent que c'est difficile d'améliorer la qualité de l'air dans les écuries. Les scientiques ont montré qu'une gestion efficace de l'ensemble de l'écurie a des effets bénéfiques (ndlr: on s'en serait douté...)

    They found that changing the feed from hay to haylage, and the bedding from straw to shavings, at the same time as improving the ventilation, led to a fall in the RDC. This was apparent both in the stable containing the horse and in the neighbouring (empty) stable within the same airspace. Ils ont découvert que le fait de remplacer le foin par du préfané et la paille par des copeaux, en même temps que d'améliorer la ventilation permettait de faire baisser le taux de poussières (ndlr : ça aussi on l'aurait découvert)

     


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