Silage and Animal Health

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Silage and Animal Health Powered By Docstoc
					Complete set of Silage Notes By
Frank Mickan, Fodder and Pasture Specialist, Natural Resources and Environment, Ellinbank .

Table of Contents Silage and Health ____________________ 3 Silage for Drought Storage_____________ 6 Storage of Large Square Baled Silage ___ 8 Mouldy Silage, Listeriosis and Sheep! __ 11 Filling and Sealing Silage Stacks_______ 13 GUIDE TO THE DRY MATTER TESTING OF SILAGE ____________________________ 15
Hand Method .................................................................................... 15 Microwave Method ........................................................................... 16

Should I use silage inoculants or not? __ 17
What are inoculants? ........................................................................ 17 How do inoculants work? ................................................................. 17 Will I make money if I use them? .................................................... 17 Why do I get conflicting information? ............................................. 18 When are inoculants most effective? (Based on research to date) . 18

Getting rid of baled silage wrap. _______ 19
What has happened so far? .............................................................. 19 What can farmers do with the used film for now? .......................... 20

Protect Your Wrapped Bales __________ 21 Speed up wilting ____________________ 23
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MOWING AND WILTING ______________ 25
Keep it in the Back of Your Mind. ................................................... 25 AM Vs PM mowing: ......................................................................... 25 Mowing & Wilting. ........................................................................... 26

If rain is on the way and you won't have all the bales under cover (shedded or tarped) before it arrives, what can you do? ................ 28 What happens after the rain?........................................................... 28

If rain is coming and you won't be able to shed the bales before it arrives, what can you do? ................................................................. 30 How do you manage hay bales that have become wet? ................... 30

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“Animal and human health problems associated with silage are not very common but when they do occur, they are not quickly forgotten!” says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank. Animal health problems can appear as decreased intake and resultant decreased production, abortions, scouring and even death! However despite silage being the obvious and guilty party in many cases, it is also the scapegoat for many not so obvious causes, bit like snakebite as a cause for dead animals with no obvious reason. That’s the bad news but the good news is that most of these need not occur at all. Proper silage harvesting and storage will minimise any such problems. - Harvest quickly(24 – 36 hours ideally) - Ensure that dirt, manure and dead animals are not incorporated - Compact the stack or bale very tightly - Seal the stack or bale airtight with plastic or alternative as soon as possible after harvesting is completed - Regularly check and repair any hole immediately - Feed out at least 150 mm of silage face each day (300 mm every 2 nd Day) - Ensure baled silage is eaten by day 3 once opened. Hazards to human and animal health can be caused by undesirable micro-organisms such as Enterobacteria, Listeria, Clostridia, moulds/fungi, and by mycotoxins. Surveys have revealed a huge variation in the preservation qualities of silages, with many being unstable and badly preserved. Rapid lactic acid production in anaerobic conditions is the desired type of fermentation. It is when this environment does not occur, or is later changed, that most problems occur. Undesirable Micro-Organisms Undesirable micro-organisms can enter the silage storage by soil and livestock waste during harvest or increase in numbers by an environment suited to them in the silage storage. Enterobacteria. Also known as coliform organisms, the most important microorganism in this group is Escherichia coli (E. coli) species and can cause diarrhoea and death. E. coli and other related enterobacteria (Bacillus and Clostridia species) become a greater risk when effluent is applied to paddocks closed for silage. Effluent sprayed onto paddocks closed for silage must be well washed in by rain before harvesting. A slow fermentation favours the growth of enterobacteria and so these guys can compete more strongly for the water-soluble carbohydrates (plant sugars and starches) with the more desirable lactic acid bacteria in the early phase of fermentation. The result is that less lactic acid is produced and the desired rapid decrease in pH ie. increase in acidity, does not occur. Leguminous crops such as balansa clover and lucerne have a higher buffering ability

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than grass type silages and pH decrease can be slow. That is, they are less inclined to undergo a satisfactory fermentation once ensiled. However wilting leguminous crops quickly to 33 – 40% DM for chopped silage and 40 –55% baled silage will reduce this problem. Listeria Listeria monocytogenes is found in soil, faeces and rotting vegetation and can reproduce at low temperatures, as well as in heating silage. It is more commonly found in the out layers of baled silage although it may occur in the layer just below the plastic sheet in chopped stack silage. Slow air entry via holes, poorly wrapped or insufficiently wrapped bales and plastic degradation can lead to this problem. As the silage breaks down the silage pH rises, ie. becomes less acidic, and upon air entry, water, carbon dioxide and heat are generated. The moisture, rising pH and slow air ingress favours the Listeria blighters. If possible avoid feeding the obviously mouldy silage to pregnant animals. Do not feed it to sheep as they are particularly vulnerable to Listeriosis. Prevention is the most effective cure by following the proper harvesting and storage requirements mentioned above. Clostridia The direct effects of clostridial fermentations on animal and human health are less evident than those on silage composition quality. These anaerobic (without air) bacteria are responsible for the secondary fermentation of glucose and the more desirable lactic acid to a less desirable butyric acid. Clostridia bacteria are also the cause of excessive protein breakdown. Clostridai bacteria could grow in wet silages which have a pH above 4.6, which can occur in pit silage where air has gained entry. The silage is not pleasant to smell. The bales are often shrunken, effluent in the bottom and sagged heavily. Costridia affected silages are less palatable, have a lower digestibility silage and results in reduced intakes and possibly signs of acetonaemia in high yielding cows in early lactation. The extensive protein degradation of plant proteins to ammonia may also have detrimental effects on animals although scientists debate this issue. Clostridium botulinium is the Clostridia bacteria of most concern to health. The risk of botulism is increased substantially if the crop is contaminated with animal remains. Botulism has been reported from silage to which poultry manure was applied. Horses are most susceptible. Clostridial spores from silage can infect milk and cause problems in cheese making. Moulds/Fungi Fungal spores pose health problems in two ways. Firstly as airborne spores affecting mucosal surfaces of the lungs and respiratory passages, and secondly as metabolic disorders from ingestion of fungal mycotoxins. Humans and horses are more at risk of respiratory disease than ruminants but the disease caused by silage is rare due the open areas associated with its feeding. Respiratory problems, such as farmer’s lung, are more common in mouldy hay, especially in enclosed areas such as hay sheds.

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Figure 2 shows an extremely mouldy bale of silage. Mycotoxins Mycotoxins are products of fungal metabolism and can be found in silage, hay and any feed that has deteriorated during storage. To produce toxins fungi need a temperature above freezing, a moisture content above 20%(ie. less than 80% DM), and air (oxygen). For the scientifically inclined reader, Fusarium, Aspergillus and Penicillium are the most prolific producers of mycotoxins in silages. Mycotoxins of concern are deoxynivalenol (DON), aflatoxin, T-2 toxin, zearalone, moniliformin, ochhratoxin, roquefortin C and patulin. They are most likely to be found in silages that have undergone aerobic spoilage. Mycotoxins affect animals through three mechanisms: a) alteration of nutrient content, absorption, and metabolism b) changes in endocrine and neuroendocrine functions c) suppression of the immune system. Signs of mycotoxicosis in animals are reduced feed intake, decreased animal performance, poor fertility, and increased incidence and severity of disease. However mycotoxin presence may not always be the blame for poor animal performance. Even if they were, the multiplicity of potential toxins renders it sometimes impossible to diagnose accurately the cause of the disease. But mycotoxins can be a serious hazard to both animals and humans and so their presence should be minimised by proper harvesting and storage. Considering the increased importance of silage as a feed for livestock more studies are needed to establish epidemiologically and mechanistically the risks to animal and human health from silages contaminated with pathogenic bacteria and mycotoxins. Research is also needed to understand more completely the relationships between the physical and chemical composition of silage and metabolic disorders in animals. Farmers will then be in a position to avoid the predisposing conditions by changing crop and ensiling management.

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"Many areas of Australia have experienced drought over the last few years," says Frank Mickan, Pasture and Fodder Conservation Specialist, Department of Natural Resources and Environment, Ellinbank. These periods usually exhaust all supplies of the farm's fodder reserves and often requires large purchases of fodder from outside suppliers if the drought is prolonged. The costs of these extra fodders are generally very high, and its quality is often very poor, particularly as fodder supplies becomes short. Then there is the extra hassle of possible diseases and weeds coming onto the property with the hay. Conversely there are also often periods of pasture growth which far exceeds the requirements of animals, refilling the hayshed, or excess to the silage supply. This feed, if not utilised by grazing or slashing, will become ranker and its quality will deteriorate substantially. This should be the source of your next drought reserve. Rather than wasting it, put it into a clamp, pit or bales for the next long dry period or drought. Although you may be pinched for $$$ after the fodder harvest, think carefully about the high cost you paid for extra hay of poor quality last drought. It will have cost you 1.5 to 3 times the cost of this pasture you may be allowing to go to waste. It was hard to find money for extra drought fodder but, hopefully, you may soon be in a better position financially to put away an extra pit, or bales of silage as a drought storage. Why silage as a drought reserve? Why not hay? Unless your climate is suitable for making good quality hay and these hays are legume based, eg.s lucerne, balansa or sub clover, the quality is usually average to poor. Many hays made are well below about 8.5 megajoules of metabolisable energy per kilogram dry matter (MJ ME/kg DM) because the climate dictates that harvesting is done when the pastures are much more mature, ie lower in quality. This is suitable for animals to maintain on or for low liveweight gains, but is insufficient for high milk or meat production. For this the feeds should be close to although preferably above 10 MJ ME/kg DM. Many farmers argue that poorer quality fodder is sufficient for drought feeding and they would rather have the increased bulk of feed than less feed of higher quality. Alan Kaiser of the Wagga Wagga Agricultural Research Institute have estimated the total cost of conserving, storing and feeding out silages of different quality to feed 100 dry cows for 6 months so that both groups maintained liveweight. These costs also included an estimate for losses at all stages. The total costs of the silages with qualities of 7, 8.5 and 10 MJ ME/kg DM were $12688, $9990 and $8160 respectively. Hay, even when made with no weather damage and shedded, will lose about 4 to 9% of its dry matter within the first 12 months, and a further 2 to 5 % in the second year. Its quality will also drop over several years and this is without substantial damage caused by rodents, misty weather, risk of fire, leaking rooves, etc. Hay left in the open will lose 25 to 30 % dry matter in moderate rainfall areas. Silage has the potential to be of quite high quality, above 9.5 MJ ME/kg DM, if harvested early and quickly in the season. It should be cut before the seed heads start Page 6 of33

to emerge then sealed well, and quickly! Provided the stack or bales are not punctured during the storage period, its quality will be maintained for many years will little loss of dry matter. If silage quality was lifted by 1 MJ ME/kg DM then 10 kg DM of this silage would produce about an extra 0.5 – 0.7 L milk. and concentrate feeding could be substantially reduced. depending on feed source, quality of silage and base feed, amount of pasture available, etc. Silage for drought storage can be stored as chopped silage in pits or stacks, or in round or square baled form. The pit or stack silage must be sealed airtight, preferably with plastic sheets and then covered with 300 to 450 mm of soil. Soil only can be used as a cover but may result in some contamination at the silage/soil interface. Also if burrows or holes into the soil cover appear over time, a plastic seal may stop water soaking into the silage, which can and has led to large quantities of rotten silage in many stacks. Make sure water is drained away from the top and sides of the stack. A tile drain installed into a 100 mm wide trench to a depth that underground water infiltrates, and backfilled with gravel or sand, will intercept any underground water. Round bales of silage should be wrapped in 4 layers of plastic, placed in a pit in the ground or hillside, and covered with soil as above. Unwrapped bales in a pit covered with plastic will store satisfactorily but will sustain large losses if rabbit burrows etc. go through the top soil cover and allowing air to enter. Also once the stack of bales is uncovered for feeding out, air will move back between the bales commencing secondary fermentation and rapid decomposition. If storing unwrapped bales in a pit, stack enough bales for about 6 days feed in each group and seal each section completely airtight with plastic film. Wrapping the individual bales greatly reduces any problems of air (and water) entering the stack at any stage. Square baled silage is more suited to being stored in compartments in pits without the need for individual wrapping of the bales. This is due to their density and shape which allows tighter stacking, ie less air intrusion between bales. Make stacks of bales needed for up to 10 to 12 days in each group. However the drought storage should still be covered with soil to protect the plastic from ultra violet light break down. Finally, if the storage site is not obvious, mark where the drought storage is located. Many farmers, or new farm owners, were not aware of where the drought storages were located during the last drought.

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“Storing large square bales of silage under sheets of plastic should be cheaper than being individually wrapped”, says Frank Mickan, Fodder and Pasture Specialist, Natural Resources and Environment, Ellinbank. However this is often not the case because many bales are mouldy when unsealed! These mouldy bales Mouldy silage (see Figure 1) usually occurs due to the presence of air in the stack. Mouldy silage represents a loss in dry matter and silage quality. The amount of loss will depend on the extent of mould and deterioration of the bales. The moulds, fungi, bacteria, yeasts, etc. which set up camp and multiply profusely in these ideal conditions actually “feed” on what you were try to preserve for your animals, the energy and proteins. Under these conditions the silage also breaks down into carbon dioxide, moisture and heat. The hotter the silage the higher the proportion of dry matter and quality is being lost, and the more these blighters like it! Following are some possible causes of various degrees of the mould problem. 1. Small areas of mould on the bale exterior after several months of storage. The plastic sheet may have a slow leak due to a small hole or air is entering the stack at the bale-ground juncture, or the folded ends are not airtight. 2. Large areas of mould on the bale exterior after several months of storage. Large or many holes in the plastic sheet is allowing a lot of air to enter, or the seal at ground level is not totally airtight, or the folded end flaps are not very airtight. 3. Large areas of mould on bale exterior, mould “growing” inwards to the bale interior from the outer edges, bales may be warm. Very large or many holes in plastic sheet or very poor seal at base of stack or folded ends ineffective. If the bales are tight then the air has been entering for quite some time. 4. Large areas of mould on bale exterior, mould throughout most bale interiors, bales generally will be hot! Very large or many holes in plastic sheet or very poor seal at base of stack or folded ends ineffective or the air has been entering for a long time. Bales may have been baled relatively “loosely”(for large squares) or the crop may have been too mature, ie stemmy. 5. Any of the above with effluent flowing out of stack bottom. This effluent could be from silage made too wet, or as a result of the silage deteriorating from air entering the stack and braking down to gas, heat and water. For stacks above ground seal enough bales for about 14 – 16 days feed in each compartment. If stacking large square bales into pits in the ground, use plastic sheets to seal stacks into compartments containing 16 - 20 days feed. This is suggested

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because if the top of the sheet is holed by cattle, rabbits, dogs, kids, etc. then only the holed compartment will “go off”, provided the seal between compartments is effective. When you start feeding out, the air can only go back to the next compartment. Putting dirt around the edges of the stack and or down the pit sides will help to form a good seal. If the plastic is billowing in windy conditions, too much air is probably entering somewhere! See diagram 1 for recommended sealing in pits. Use proper plastic tape specifically made for silage film. Grey duct tape is no good. Ensure the plastic is dry, clean and cool before applying plastic to holes. Cut tape to length, let it shrink back, then apply it.
Airtight Seals Plastic sheets Tyres

Large square silage bales Pit Wall

Diagram 1. Large square bales in well sealed compartments in pit. Using dirt to seal at the bale-ground interface can ensure an excellent airtight seal. Dig a trench before or after the stack is built. Place the plastic sheet into the trench, folded so that the edge sticks back up out of the ground trench. Dirt is then placed into this trench against the plastic. The jutting plastic sheet edge is then easily pulled up when unsealing the stack. See diagram 2. An alternative is to lay the sheet edge on the ground and cover it with dirt, ensuring the film edge is covered.
Plastic folded at corner Large square silage bales Plastic folded and buried Plastic rolled at corner

Soil over edge of plastic

Diagram 2. Well sealed stack showing ground sealing techniques

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"Sheep and mouldy silage do not mix!” says Frank Mickan, Pasture and Fodder Conservation Specialist, Department of Natural Resources and Environment, Ellinbank. All forms of silage (pits, bun stacks, round and square bales) are being more commonly used in the extensive grazing industries of beef, sheep, goats, horses, alpacas and even ostriches. This silage has the potential to produce high performance from all classes of animals if conserved early in the season when the pastures are leafy and contain some clover but must be harvested and sealed airtight quickly, However shortcuts, lack of experience, lack of attention to detail, and not repairing holed plastic, has resulted in many storages, particularly round baled silage, becoming mouldy. There have a few cattle losses, and a worrying number of sheep being affected, including deaths. Most sheep deaths have been due to Listeriosis. This won’t occur if the silage is made and stored in such a way that mould does not occur! Listeriosis is caused by a soil borne bacteria, called Listeria monocytogenes. It is an opportunistic pathogen affecting animals with a depressed immune system such as pregnant ewes. Although widespread in the environment it is usually in such low numbers as not to be a problem normally. The listeria bacteria can be problematic in three ways. Consult your vet for the correct treatment. 1. Nervous disease: This is the most common occurrence and is characterised by meningitis, abortion in late pregnancy, and conjunctivitis, referred to as "silage eye". It is thought that the organism gains access to the animal's nervous system via damage around the gum or teeth. It quickly becomes sick, unsteady on its feet, drooling at the mouth, and if not treated promptly, will lie down and die. 2. "Circling disease": The bacteria affects the brain and causes the animals to often walk in circles, hence the name. 3. Septicaemic form: The sheep will have a listless appearance, often having diarrhoea, and dragging the hind legs. When grass is contaminated with soil the risk of listeriosis (and other diseases) is higher, and usually corresponds to when the silage pH, or acidity, is approximately pH 5.0 and above. The mould which causes Listeriosis usually only occurs in poorly preserved silages where air has gained access slowly to the silage. This results in aerobic deterioration, i.e. the silage starts to deteriorate, and all sorts of nasties, such as yeasts, bacteria and moulds, rapidly increase in numbers. Listeria bacteria are usually confined to the outer surfaces of bales and clamps where the air has entered slowly and the pH has started to rise. Aerobic deterioration can be due to: * insufficient wraps of stretch-wrap plastic film (a minimum of 4 is essential) on bales

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* incorrect plastic overlap (at least 50% overlap for individually wrapped bales) * excessively dry and/or rank plant material has been ensiled * poorly compacted bales or stack of silage * plastic sheets sealing stacks not weighted sufficiently * holes in the plastic film not being patched quickly enough or effectively when done * spike holes when moving bales not being filled with grass (or other filling) once moved. * plastic film degradation. Most of the Listeria contamination is in the visibly spoiled material. Removal of this before feeding to sheep will greatly reduce any possibility of listeriosis. Listeria bacteria are usually not present in completely deteriorated (i.e. composted) silage because of competition from the putrefying bacteria. The best method of preventing listeriosis is to ensure that well shaped, tight bales and stacks of silage are quickly and well sealed as soon as possible after harvest with an airtight seal. If the seal is punctured, it must be sealed as soon as possible. Air = mould = possible Listeriosis.

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“There are no short cuts when sealing stacks of forage harvested silage,” says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank. Sticking a few tyres on top to hold the plastic down and throwing a bit of dirt around the edges is not a suitable airtight seal. If mould is present when the stack is opened, then air is present, or has been. The more air, the more mould! Where has this air come from? Many farmers can open a stack up at feeding time to reveal perfectly stored silage with no visible signs of waste from decomposition or mould. How do they achieve this? Silage made at a suitable dry matter (DM) content. Stacks are tightly compacted by rolling during harvest. Stacks are sealed straight after harvest. Plastic sheet on top of the stack is well weighted. Stack is sealed airtight at the edges of the plastic. Holes which occur are fixed immediately. Stock damage is prevented by well constructed fences and gateway. Crops harvested with loader wagons, double choppers, etc. which harvest relatively long chopped material (~ 5 – 15 cm) should be harvested at about 28 – 35% DM. If the material is much drier than this compaction by rolling is much less effective unless an extremely heavy machine is used. Not enough air will have been excluded. Precision harvested material (~ 1 – 5 cm) can be ensiled at about 40 – 50% DM as its length allows easier and better compaction, but the stack must be well sealed or the benefit will be lost. This shorter and drier material will require about one third less storage volume. If material of either length is becoming too dry as harvest progresses due to machinery delays, dramatically rising temperatures, etc. spread some loads of freshly cut or lightly wilted material. This will ensure a much more satisfactory compaction and air exclusion. Many operators roll the stack too quickly! Roll slowly to allow the weight of the tractor to compress the material. Spread the harvested material thinly in layers of about 150 – 200 mm. Large clumps or thick layers will not allow complete expulsion of the air despite rolling. If the stack is above ground and has no support walls be very aware of rolling the edges. Use the front wheel to compress the edges by driving to and from the edges on a slight angle turning the front wheel along the stack, but stopping when the rear wheel approaches the edge. For cement bunkers, if the top of the stack is likely to finish below the tops of the walls, thus making sealing very difficult and possibly allowing water/air entry into the stack via the edges of the walls, consider building the stack edges higher than the middle. The resultant depression in the middle of the stack will allow water to run off, and allow the full extent of the tractor’s weight to compact the edges.

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It is preferable to pull a plastic sheet over the stack at night. Place tyres around the stack edges and a few in the middle to weight down the plastic. This will reduce the amount of air gaining access to the stack at night as the hot gases move out of the stack at a greatly reduced rate. Ideally, the stack should be completed within 1 – 3 days. If at any stage you see steam rising from the stack when the silage face is lifted, or high temperatures are felt upon inserting a hand into the stack face, losses of energy and protein are becoming high. This is often noticeable when filling a stack over a longer period than 3 days, if rolling is inadequate, or the material too dry. Seal the plastic sheet at the edges to be airtight. Two excellent seals are shown in Diagram a and b. The folded plastic edge (diagram a) ensures an airtight seal and is easily pulled out when the stack is opened. If the dirt does not cover the edge of the plastic, air entry into the stack is highly probable (diagram b).

Plastic folded Dirt seal



Dirt seal

Plastic Edge covered

Diagram a. Folded plastic is a good seal. Diagram b. Dirt seal prevents air entry. Overlap plastic by at least 0.5 m and preferably seal with a tape specifically designed for silage films. The film must be dry, clean, cool and the tape allowed to shrink before applying it to the plastic sheet. Weight the plastic all over with tyres, dirt, thin layer of soil with grass seed sprinkled on top. Fence off so that stock cannot stray onto the stack and cause holing in the plastic sheet. Seal any holes as soon as they are noticed.

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“Silage should be made at the correct dry matter, if possible, to ensure a desirable lactic acid fermentation in the absence of air soon after harvesting and sealing,” says Frank Mickan, Fodder and Pasture Specialist, Natural Resources and Environment, Ellinbank. Undesirable and/or mouldy silages will be the result of silage made too dry or too wet. These silages will be less palatable, lower quality and not so pleasant to smell or handle. The following dry matter contents are suggested for the various silage crops and type of harvesting. Crop type Pit/stack (DM %) Bale (DM %) 40 – 55 40 –55 40 – 50 35 – 45

Pasture Long chopped 28 – 35 Precision chopped 35 – 50 Leguminous crops Long chopped 33 – 45 Precision chopped 35 - 50 Whole crop cereal Wilted and Fermented(Leafy) 28 – 35 Direct Harvested(Soft dough) 35 – 45 Maize Precision chopped 32 – 35 Summer Forages Long chopped 28 – 35 Precision chopped 35 - 50

35 – 45

There are two methods for measuring the dry matter of pastures to determine their readiness for ensiling. These are the hand and microwave methods. The current hay moisture meters are not suitable for silage! Initially the microwave method could be used to calibrate your own hand method or some other technique that you could develop for quick paddock use.

Hand Method 1). 2). 3). 4). 5). Take a representative sample of pasture ready for ensiling. Cut into 1 - 2 cm lengths. Tightly squeeze a handful for 20 - 30 seconds. Quickly open your hands. Discern approximate dry matter content from table below.

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Dry Matter Content Below 25% 25% - 30% 30% - 40%

Condition of the Sample Ball holds its shape. Lots of free juice. Hand is wet or moist. Ball just holds it shape. Hand barely moist. Ideal for wilted chopped stack or pit silage at drier end of range. Ball falls apart slowly. No free juices. Makes excellent silage, but because of its springiness, requires fine chopping or extra care to exclude air at drier end of range. Ball springs apart quickly. Suitable for round/square bale silage and precision chopping but total air exclusion is essential.

Over 40%

Microwave Method 1. 2. 3. 4. Collect representative samples from the crop and thoroughly mix together sub sample to get a test sample. Weigh out approx.100 g sample of the chopped forage excluding the weight of the container. Weigh to the nearest gram. This is the initial wet weight. Spread the weighed forage sample on a paper tray and put it in the microwave oven. Place a 250-ml glass three-quarters full of water in the oven to prevent igniting the sample after some initial drying. Maintain water level during oven use. Heat at 80 to 90% of maximum power for 4 minutes if sample is estimated to be 30 - 50% dry matter. Remove the sample, mix and weigh. Continue to re-heat for 1 - 2 minute intervals, re-weighing each time. To prevent burning use lower heat and 30 second time intervals as the sample approaches being dry. If the weight of the sample does not change after two or three drying intervals, it is 100 per cent dry within 1 – 2% units. This is near enough! This is the final dry weight. If the sample burns use the last recorded weight. Calculate dry matter content as follows :Final Dry Weight (gms) Initial Wet Weight (gms) e.g. 1. 33 gms 100 gms 48 gms 112 gms X 100 = ………% Dry Matter 1 X 100 = 1 33 % Dry Matter

5. 6. 7.


e.g. 2.

X 100 = 42.8 % Dry Matter 1

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“What are silage inoculants? Are silage inoculants worthwhile? How do they work? Will I make money if I use them? Why do I get conflicting information?” “These are just some of the many questions farmers and contractors continually ask me concerning silage inoculants,” says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank, Gippsland. What are inoculants? Inoculants are only one of several types of silage additives. Types of additives include acid based additives (containing formic or sulphuric acid), fibrolytic enzymes (containing celluloses, hemicellulasesand glucose oxidase), sugar based additives (molasses or sugar beet pulp), enzyme/salt mixtures (sulphur and sulphite compounds, various enzymes), salts (sulphur and sodium salts some, with bacteria) and biological inoculants (bacteria such as Lactobacillus, Pediococcus species, some with enzymes, some with sugars). Most additives are not available in Australia, as yet, nor are they needed under Australian conditions. However the most common and most useful additives used in Australia are the biological inoculants. Molasses is also proving useful in bad weather situations. How do inoculants work? Silage fermentation is influenced by the types and numbers of naturally occurring micro-organisms, the amount of soluble or fermentable sugars, the rapid elimination of oxygen, silage dry matter content and the buffering capacity (it’s “unwillingness to become silage”). As the crop starts to ensile (ferment) a war begins between the good bacteria (lactic acid producers) and bad guys (enterobacteria, yeasts and moulds). Wilting quickly, excluding air, sealing quickly and well all favour the good guys. Bacterial inoculants contain a certain quantity of the good types of bacteria. These added bacteria increase the numbers of naturally occurring good guys and may (but not always) help to win the war. RESULTS: A quicker fermentation with less loss of sugars and proteins in the silage, often a reduced secondary fermentation at feeding out, reduced dry matter and quality losses, and hopefully increased animal production. Will I make money if I use them? Up to recently my reply has been that, at the least, you should get your money back, and possibly a bit more in some circumstances. These “circumstances” were not very clear. This reply was based on a summary of inoculant research by Professor Keith Bolsen of USA as shown in Table 1. However the latest research is concentrating on developing and selecting strains of bacteria that are more effective than those used several years ago. Many bacteria strains today contain higher numbers and are crop specific rather than a shotgun approach.

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Recent research by Alan Kaiser at the Wagga Wagga Agricultural Institute has measured animal responses with inoculant treated silages compared to untreated silages even though he found no chemical differences between them. Be aware that inoculants are a large group and highly variable so their effectiveness will vary also!

Why do I get conflicting information? This was due to the above factors and to the wide range of silage fermentations, weather conditions, inaccuracy of application, wrong types of bacteria used, etc. that occur on farm compared to well controlled experimental conditions. Over zealous manufacturer’s claims has not helped either.

When are inoculants most effective? (Based on research to date) They are not suited to silage making in poor weather conditions. They may work if the crop is harvested, wetter than desirable, after less than 2 days on the ground. They are more suited to lucerne and pasture silages and less so in maize silages. Use inoculants which apply at least 100,000(1 x 10 5) bacteria per gram of crop although others apply 1,000,000(1 x 10 6). Use inoculants which contain at least Lactobacillus plantarum. Inoculants must be applied uniformly to the crop as it is cut. They do not swim! Store in a cool dry place. Do not leave in hot situations Mix and apply daily if possible, they will not survive long. Inoculants will not fix up a stuff up!

Table 1. Benefits of Bacterial Inoculants Measurement Fermentation characteristics Reduced in-stack losses Aerobic stability improvement Dry matter intake Liveweight gain Milk production Feed efficiency Studies showing positive response(%) 65 - 75 74 42 25 25 40 50 Mean response in studies(%)

2.5 0 11 11 5 9

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“Many farmers in most areas are still waiting to hear about where and how they can dispose of baled silage wrapping plastic,” says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank. He has been involved with the Silage and Mulch Film Task Force which has been actively pursuing the limited options for post consumer use of baled silage film. The Silage and Mulch Film Task Force consists of representatives of the major Plastics manufacturers, Department of Natural Resources and Environment, and the Plastic and Chemical Industries Association (Pacia). What has happened so far? The group has searched world wide for feasible and environmentally friendly ways to make use of this used plastic. It soon became clear that Australia was unique in this problem. Compared to countries such as the UK, Europe and the USA, the economics of recycling were very much in the negative due to such factors as the distances involved versus the relatively small volume of plastic used. These overseas countries have all had their own sets of favourable and unfavourable circumstances. Some Governments actively assisted some programs by various means of support such as tax assistance. However many recyclers have since ceased operation due to lack of demand for recycled products, uneconomic operation, oversupply of recycled plastic, relatively cheap raw materials, etc. In Australia no assistance is provided so that the cost of a recycled product would equal or even be above the cost of a similar product from virgin plastic. Not many people would purchase a recycled product for the same price as one manufactured with raw material! The stretch wrap plastic used on baled silage is unique in its construction which makes it difficult to recycle without great expense. Australia is at the forefront of recycling technology and product development and may end up providing other countries with the solution to this problem. There are several other problems on the manufacturing end such as treating the washing water, heating the old plastic to change its format, old perished film mixed with relatively young film, the cling or tack in cling wrap film causes costly and time consuming problems with the recycling machinery, etc. However the group has pursued several options, the recycling options being the most desirable choice, and as a source of energy being the least desirable. Progress has unfortunately been slower than expected. The first production trial runs at two recycling plants have ran into some unforseen problems. This was disappointing in light of the highly successful used silage wrap collection organised

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by Jennie Hermiston of the North East Region Waste Management. However the Silage and Mulch Film Task Force is committed to finding an economic solution to this waste management problem. Some technical advice has been sought to facilitate the recycling of this plastic and further trials are expected to be conducted shortly What can farmers do with the used film for now? Something WILL happen eventually and this plastic is very useful for whatever eventuates. The most desirable strategy is to store the used film in a clean, dry area, with no extra contaminants. These contaminants are string, excess silage, rats, wire, steel posts, wood, etc. which makes the plastic unable to be recycled. A less desirable option, although the only legal alternative option, is to deliver it to a local landfill, if they will accept it. Most Environmental Protection Authorities (E.P.A.’s do not permit the burning of plastics on farm. It is also undesirable to bury plastic on your own farm, although not illegal, because once covered by soil, the plastic will last many years. It will eventually be broken down by soil microbes (over many years). It is highly unsuitable as a fill in holes and gullies since it will not bind with the soil and may lead to landslips, sinking holes, plastic eventually finding its way to waterways, etc. A meeting with the involved groups will be held soon to further progress.

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“Many farmers in Australia making individually wrapped round and large square baled silage are having a range of problems during the storage period, apart from mouldy bales”, says Frank Mickan, Fodder and Pasture Specialist, Natural Resources and Environment, Ellinbank. These problems are caused by a wide range of sources such as rodents, sugar ants, a variety of birds, cats, foxes, underground grass caterpillars, children, etc. Most problems can be overcome or reduced by persistence, careful location of storage area, farmer innovation, and a few handy hints. All new technologies have their fair share of hiccups and particular problems in specific locations is one of the irritations of wrapped baled silage. Research in Ireland has found that painting an eye design on the bales was found to reduce damage to bales by 70 – 80% when compared to nets or strings at 1m spacings. However strings spaced at 0.5m or even closer was found to be more effective than 1m spacings. These strings tend to make landing and “taking off” as the strings foul the bird’s wings. The height of the strings above the bales, although not mentioned, should be about 20 – 40cm. Humming wires such as a small plastic strip used for scaring birds in horticultural situations, has been effective on some farms. A good example of their use by a farmer entailed tying the humming wire to the handles of four 20L plastic containers. These were positioned to form a diamond shape above the bales so that regardless of wind direction, humming occurred. Another farmer innovation is the placing of tyres on tops of bales. Either the bales are “seen” as a haven for snakes, or the tyres make landing and embarking precarious. This has met with varying success. Locating bales away from buildings will greatly reduce damage from rodents (mice, rats), cats, dogs and children. Some farmers have used a plastic sheet to prevent direct sunlight on the stretch wrapped bales thus ensuring a longer life of the stretch wrap. However they have now built a paradise area for rodents in particular because the “roof” offers a dry, warm environment and protection from mice eating birds such as hawks. Placing bales on clean areas by spraying the plants or laying down a sand or sawdust base may also reduce rodent problems. Whole crop cereal silage which contains grain seems to attract rodents like a magnet so it should be stored well away from the cereal growing paddocks. If made in the leafy (flag leaf or boot stage) stage, the mouse problem is greatly reduced but so is yield although quality will be quite good. An all too familiar site are bales which have been fenced off by a single electric wire but subsequently have been holed badly by animals due to a power failure or falling victim to a daredevil animal that thrives on electric fence shocks. Also many bales are often placed too close to traditional fences so that they are easily chewed by animals

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next door. If the damage is not noticed quickly the animals develop a liking for the silage and eat so much that a quick fix with tape is a complete waste of time! Bales should be stood on end after wrapping. The extra film on the ends offers more protection against most birds (cockatoos are an exception!), the bales hold their shape better, and any UV light degradation of the plastic is minimised. I would very much appreciate any feedback or suggestions from farmers, contractors and fodder machinery dealers about the problems they have experienced and the “fixes” which have been successful. Please ring (03)5624 2222, Mobile No. 0427 317 471 or email

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“Wilted silage, ideally, should be in the pit or bale within 24 – 36 hours of mowing,” says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank. The longer the cut pasture or crop is wilted on the ground before harvesting, the larger the losses in quality (energy and protein) and dry matter. Also greater is the risk of the next shower of rain resulting in even higher losses. Good quality silage will be over 9.8 Megajoules of Energy per kilogram Dry Matter (MJ ME/kg DM) and will produce rapid growth rates in beef cattle or extra milk in lactating cows. To achieve this quality pasture is usually cut 2 – 5 weeks before you would normally be cutting hay in most areas. There are a few exceptions to this rough guide such as lucerne, sub clover, vetch and maize crops. This means that you will be harvesting when the ground is moist, the weather is cool – warm only, and may even be overcast. How can harvesting be achieved in these circumstances? Sometimes it won’t be, but there are a few management tips and machines now more readily available that can make this possible. Harvesting high quality crops early in the season can be achieved by:- cutting lighter crops. - allowing the dew to lift before mowing and subsequent treatments. - mowing with a mower conditioner. - mowing with a mower conditioner but leaving a wide swath. - spreading/tedding immediately after mowing. Harvesting early in the season often means cutting lighter crops (stubby bottle to beer bottle height) which will dry quicker than if cut at the stage most crops are harvested (1.5 – 2 beer bottle heights). Although yields will be down, quality will be up dramatically. Lighter swaths will take up more moisture overnight than heavy swaths but will lose it faster the next day. Mower conditioners are making a comeback and incorporate a wide range of conditioning techniques. The tyned and brush types are most suited to pastures, younger lucernes, clovers and vegetative cereal crops while the roller types are more suited to the stemmier type crops such as cereals cut with a seed head, summer forages (eg. sorghum) and mature lucernes. However the operator’s experience and conscience to do the correct job, the speed of the operation, the correct setting up and maintenance of the machinery, etc. can see an overlap of the categories above. Plant stomata, the thousand of holes per square centimeter through which the water moves in/out of the plant, close within 1 – 2 hours of mowing, depending on climatic conditions. This reduces the rate of drying and prolongs the wilting period. Tedding or spreading straight after mowing will promote increased water loss via the open stomata by an extra 50 – 80% for a few hours. Tedders are machines which operate, usually in a horizontal plane, to spread the mown swath so that all ground is covered and the plants are left more “teased up” into the air than if mown only. Some bruising of plants will also occur at the same time promoting faster water loss.

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Table 1 shows the results on an experiment in Ireland which compared different types of swath, and conditioning or spreading versus no drying treatment. A perennial ryegrass crop, very wet at mowing (13.3 % DM) and 30 tonne/ha fresh weight (about 4200 kg DM/ha) was harvesting under dry weather conditions. The windrows were left as a single (single swath) windrow, left side by side (double swath) or spread after mowing(spread). Dry matter content of each windrow was measured 8 and 32 hours after mowing.
Treatment Ireland (Aust.) * Ireland (Aust.)*

Unconditioned 8hrs

Conditioned 8hrs 16.1 (29) 32hrs (32hrs) 19.3 19.4 (22) 27.3 (33)

32hrs (32hrs) 18.2 18.3 (20) 24.6



Spread 26.1 44.7 (50) * Note. The figures in brackets23.5my38.0 (44) what the dry matter contents are estimates of might have been under Australia’s much more favourable wilting conditions. Regardless of the climatic conditions , crop size, etc. many other experiments have verified the above order of increase in drying rate for pastures.

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AIMS: To mow early to ensure high quality silage & plentiful regrowth. To wilt the crop to the desired dry matter % ASAP after mowing. To compact stacks tightly, sealed within 1 – 3 days of harvesting preferably. To bale tightly, sealing within 0 – 3hours of baling, ideally at storage site. Fix holes ASAP after being noticed with specific silage tapes. Keep it in the Back of Your Mind. - Cutting a crop when sunny will yield a higher quality crop than when shady. - The longer the mown crop is on the ground, greater are the losses of dry matter (DM) and quality (sugars and proteins) due to plant respiration, and increased risk of rain. - The fresher or wetter the material, the more it is “living” and the greater the losses of DM and quality. - The lighter the crop the quicker the wilt. - The lesser the density of the swath after mowing, the faster the wilt. - Crops mown early in the season and without further treatment dry very well on top, to about 3 - 5 leaves depth only, in the first 24 – 36 hours! - Dust, mud or manure + silage = foul silage (reduced palatability and quality)! Assuming you are after high quality silage (>9.8 MJ ME/kg DM), then you will need to harvest perennial rye grass/white clover pastures 2 – 5 weeks before normally harvesting hay. This early in the season, the ground may be damp, air temperature cool to warm, and the skies often overcast. Try to harvest at the desired DM% but if rain is coming, into it! To harvest high quality silage, where soil types allow, may require extra machinery and some management changes in fodder conservation. The rewards are worth it! Consider working in with neighbours who have machinery that you do not have, using contractors, buying a crucial piece of machinery, etc. Forward planning (machinery serviced, fences cut, holes filled, tracks graded, tree and holes marked, harrows moved out of paddock, plastic seal on site, etc.), and communicating with others involved assists greatly. AM Vs PM mowing: It is true that the plant sugars are highest in the plant by mid – afternoon. However I believe that the extra wilting gained by earlier mowing, albeit at a lower sugar content level in the plants, is more than offset by the disadvantages of mowing mid-afternoon. A crop cut in the afternoon will be higher in energy (sugars) but will undergo a much shorter wilt before nightfall. These plants with higher moisture content, fueled by the dew, will have increased quality losses overnight due to their greater respiration rates. It is also highly possible that an extra day’s wilting may be required to reach the desired dry matter content. Ensiling at lower dry matter contents than desirable will

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result in a less favourable fermentation with some loss of quality and reduced palatability. Mowing & Wilting. Below are 3 scenarios of preparation of the crop up to the harvesting stage depending on the machinery on hand. In all cases the suggestion is to start mowing mid-late morning, after the dew has lifted, and finish if possible, by mid-afternoon. Dews can contain 2 – 3 tonne water/ha and dries much faster from a standing crop. Operations on Day 2 should also start after the dew has lifted. Harvest based on DM% if possible, starting a fraction early to avoid harvesting over dry material later in the day. Try to harvest 24 – 36 hrs. after mowing, and avoid delaying longer than 48 hrs. The timing suggested below are ideals. Weather, crop yields, machinery break downs, labour availability, contractor arrival, etc. will dictate the practical! DAY I 1. Mowing only: Mow the crop with a rotary disc mower. Consider using 2 mowers to get crop cut ASAP to allow a longer wilting period. 2. Mow + spread: Mow the crop with a rotary mower. Spread the mown crop with a tedder or tedder rake as soon as possible after mowing. Travel slowly to spread all material evenly. Set tedder so that tynes do not dig into the ground! 3. Mower-conditioner: Mow with a mower-conditioner. The tyned types are best for pastures. Leave the windrow as wide and thin as possible. May need to talk to the mower-conditioner with a blow torch! If using a roller type mowerconditioner, travel slower rather than faster to allow the conditioning rollers to have full affect. If the crop is heavy, the inner portion of swath may not be crimped if travelling too fast or rollers set too far apart. DAY 2 1. Mow only: Consider “flipping” the windrow if you have a suitable rake. This is not ideal and not worthwhile doing if windrows become “ropey”. If long chopping (5 - 15cm, eg. loader wagon) or precision chopping (1 - 5cm) into a stack, start late morning. If fine weather is forecast, possibly precision chop later with increased DM%. Baling is unlikely. 2. Mow + spread: Respread once the top few leaves show signs of wilting. This tedding can be at a faster speed. Depending on weather conditions you may not need to respread on DAY 2 if long chopping. Start harvesting about late morning. If precision chopping or baling, the second and possibly even a third tedding, may be necessary. The second tedding could be done mid - afternoon on DAY 1 sometimes. Start precision chopping or baling about early - mid afternoon. 3. Mower-conditioner: Harvest early - mid afternoon if long chopping. If precision chopping or baling consider starting mid - late afternoon when pasture is drier. If confident of fine weather continuing, start mid - late morning on DAY 3. DAY 3 1. Mow only: Rake into windrows 1- 2 hrs. before harvesting to allow further wilting of bottom material. Harvest regardless of DM as losses are now escalating dramatically.

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Table 1 shows the typical rate of drying for a range of machinery and swaths. The order of drying rate is typical of many experiments in pasture situations. The figures, rounded to the nearest full figure, are based on Irish research with their typical very high yields (30t DM/ha), and poorer wilting conditions than Australia. The last column is my estimate of what might be expected under our more favorable wilting conditions on Day 2 at 2 pm.
Table 1: Effect of Swath Treatments on Pasture Drying Rates

Day 1 M/c double swath
M/c standard swath1 M/c wide2 Spreading/tedding
1 2

% Dry Matter Day 1 Day 1 2 pm 5 pm 18
20 22 24

Day 2 FM 2 pm Estimate 18
22 30 39

16 16 16

21 25 29

~25 ~36 ~48+

2.4 m cut mower-conditioner leaving a 1.2 m wide swath 2.4 m cut mower-conditioner leaving a 1.6 m wide swath

Source: Oak Park Research Centre

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"Murphy’s Law says that Once you’ve baled your hay it will rain!” says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank. Many farmers are starting to realise the benefits of feeding or selling higher quality hay in recent years because they have learnt that higher quality means more meat or milk production. As a result some farmers are risking making slightly earlier hay and so increasing the risk of meeting rain head on! However earlier hay making can be greatly assisted by utilising mower conditioners and tedders. Unfortunately the higher the quality is the hay, the higher the losses when bales become wet from rain. This higher quality is due to the higher amount energy (eg. water soluble carbohydrates) and protein in the plant. When hay becomes wet plant respiration, leaching, and possibly mould, microbial and yeast growth later on, all result in dry matter and quality losses. So rain damage is to be avoided or minimised as much as possible Following are some considerations which may be of assistance to you.

If rain is on the way and you won't have all the bales under cover (shedded or tarped) before it arrives, what can you do?
Stack small square bales into a triangular stook using 3 bales on edge. Farmers often make stooks using two techniques. 1) Stand the bales on their ends in threes so that they resemble an "indian teepee". 2) Lay two bales horizontally on their edge so that they lean into each other at the top edge. This will form a "V" into which the third bale is then placed. The uncut side of the bales should be facing up since it tends to shed the water more effectively. The second technique is the better method for shedding rain off small square bales. Large square bales can be stacked in small stacks around the paddock, but it is preferable to cover them with tarps or plastic sheets.Although the outer edges of the bales will become wet, their internals should remain relatively dry, unless the rain is gentle and of a long duration. A heavy down pour is far less damaging than a persistent drizzle. Round bales, if baled tight, or net tied, will shed much of the rain. To avoid the high losses mentioned above round bales of high quality material should be shedded as soon as possible, or stacked and covered with plastic to minimise losses. A 6 x 5 bale (2m X 1.6m) contains over 50% of its weight in the outside 300 mm, so reducing wastage of round bales stored outside is essential.

What happens after the rain?
When the rain passes, if the forecast is for some fine weather (2-3 days), you may wish to leave the bales in stooks so that any breeze will increase the rate of drying. If there is likely to be only a short period (about 0.5-1 day) pull apart the stacks of small square bales to allow the outside bales to continue drying. Cart the dry internal bales into the shed. Make sure the bales are completely dry. A small section of one bale containing moisture may be adequate to cause spontaneous combustion ie catch fire, if shedded before becoming sufficiently dry. The wet bales may be carted in last if reasonably dry, but should be stacked to allow air to move through, around, and over the top of the stack to allow any heat generated by wet bales to escape and prevent needless heat build up. Alternatively and preferably, if shed space permits, use this larger area to stack the wettest bales with plenty of spacing..

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Large square bales will heat substantially if baled too wet, much less being rained upon from a great height once baled. Their larger denser nature of these bales do not allow them to "breathe" and will heat substantially. This greatly increases the risk of fire compared to small square or round bales. If not sufficiently dry when carting in to the shed, and no extra area is available to spread them out, place an object such as sleepers or tyres between layers to allow the heat to escape. It is particularly hard to guage the internal dryness of wet round bales which have been left standing in the field for several weeks so be ultra careful if they are shedded. Bales tied using netting will shed rain much more effectively than string tied bales, reducing dry matter losses by about 10% for bales left outside. Note that bales left in damp paddocks, in puddles, or affected by floods, are potential “fire starters”. All bales which are rain affected will be much damper than normal, even after a period of drying, so regularly monitor the stack for signs of dangerous heating, and do so for up to seven weeks. Many farmers in the past have spread salt between the layers of hay to absorb the moisture. Research into this practice indicates that it is not a viable option to reduce moisture or the prospect of mould/fire damage. A very large amount of salt is required to have any affect and this may cause problems if too much is consumed by cattle when fed out. The layer of salt may aid in absorbing some of the moisture at the junction between the layers, but won't have a great affect within the bales. It is the moisture deeper in the bales which causes the problems.

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"Although this winter has been very dry in Southern Australia, this is no guarantee of a rain free hay harvest”, says Frank Mickan, Pasture and Fodder Conservation Specialist, NRE, Ellinbank. If you are lucky enough to get your hay bales (small and large squares) under cover before it rains you need not read any further. However if your square bales are caught out in the rain the following considerations may be of assistance to you. If rain is coming and you won't be able to shed the bales before it arrives, what can you do?
Small square bales may be stacked in triangular stook style. These stooks could be done in two ways. Firstly stand the bales on their ends in threes so that they resemble an "Indian tepee". The second method is to stook bales on their horizontal in groups of three. The first two bales are laid on their edge so that they touch only on their top corners. The third bale is then laid on top in the "V" shaped area formed by the first two bales. The uncut side of the bales should be facing up since it tends to shed the water more effectively. The latter type of stook is the better method for small square bales. Large square bales can be stacked, and preferably covered with tarps/plastic sheets, in small stacks around the paddocks. Although the outer edges of the bales will become wet, their internals should remain relatively dry, unless the rainfall event is gentle and persistent. A heavy down pour is far less damaging than long continual drizzle. Round bales, if baled tight, or net tied, will shed much of the rain. Bales made early in the season will have a high digestibility. They should be shedded as soon as possible or stacked and covered with plastic because they will lose a large amount of dry matter and quality due to their leafiness and high content of sugars. Over 50% of the weight of a 2m diameter round bale of hay is in the outer 300 mm so anything to reduce wastage of round bales stored outside will be very beneficial.

How do you manage hay bales that have become wet?
After the rain finally clears up, pull the stacks of square bales apart to allow the outside bales to start drying. Cart the dry internal bales into the shed. Make sure the bales are completely dry. A small section of one bale containing moisture may be adequate to "fire" up a stack if shedded before becoming sufficiently dry. You may need to turn them over for a few hours drying before shedding. If bales are still damp on shedding, the bales should be stacked to allow air to move through, around, or over the top of the stack, to allow the heated air to escape and prevent needless heat build up. Alternatively, if shed space permits, or machinery shed is available, use this larger area to stack the wettest bales. If the weather turns hot leave the wetter bales outside to dry out. If the weather looks like turning nasty again, put these wetter bales on top of the dry shedded bales. However it would be preferable to spread these in another bay or shed until they were sufficiently dry. Large squares will heat substantially if baled too wet, much less being rained upon from a great height. The larger denser nature of these bales, if baled at 20 - 25% moisture (normally baled at less than 18% moisture), does not allow the bale to "breathe" and will heat substantially. This greatly increases the risk of fire compared to small squares or round bales. If you do not have sufficient area under cover to spread them out, and you must stack them, try to place something, egs. sleepers or tyres, between layers to allow the heat to escape.

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It is particularly hard to gauge the internal dryness of wet round bales which have been left standing in the field for several weeks so be ultra careful if they are shedded. Round bales can be tied using net instead of string. Net tied bales shed the rain much more effectively than string tied bales and reduces dry matter losses by about 10%. Be aware that bales sitting on damp paddocks, in puddles, or caught in floods, are also a potential risk for spontaneous combustion. All bales in the above situations will be much damper than desirable, even after a period of drying, so carefully monitor the shedded stack for several weeks watching for signs of dangerous heating. Many farmers in the past have spread salt between the layers of hay to absorb the moisture. Research of this practice indicates that it is not a viable option to reduce moisture or the prospect of mould/fire damage. A very large amount of salt is required to have any affect and this can cause problems if too much is consumed by cattle when fed out. The layer of salt may aid in absorbing some of the moisture at the junction between the layers, but won't have a great affect within the bales. Rain wetted bales will be quite wet a relatively long way into the actual bale. This is usually where the problem starts!

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How representative was that sample for analysis? "Last year, and it will happen again this, many farmers bought silage or hay bales on a hit or miss basis, "says Frank Mickan, Pasture and Fodder Conservation Specialist, Department of Natural Resources and Environment, Ellinbank. As a result many actually paid top price for feed that was next to rubbish, in terms of quality, for milking cows. Despite the inconvenience and cost of a feed quality analysis, fodder should be bought with the knowledge of its quality. This is beginning to occur more regularly particularly when high quality fodder is required for producing milk. Fodders, grains, and pastures can be tested for quality in Victoria using FEEDTEST. This is a self funded government run feed testing laboratory, and is based at the Pastoral and Veterinary Research Institute at Hamilton. FEEDTEST kits with instructions enclosed are located at most DNRE offices. Fodder quality is reported in terms of the digestibility and crude protein percentages on a dry matter basis, metabolisable energy as megajoules of metabolisable energy per kilogram of dry matter, and the dry matter and moisture contents of the feeds being tested. Other tests, such as neutral detergent fibre, are available at extra cost. This report must be based on a healthy and representative sample of the feed being made/bought/sold. However there are some traps for the unwary. Farmers purchasing fodder unseen and untested from unknown sources are asking for trouble. Even if purchasing fodder on a FEEDTEST basis there are many unseen and unknown traps for the unwary. Please think about some of these questions when purchasing fodder in the future. How many hay bales and subsamples were taken to make up the final sample for analysis? Was the sample taken from the same stack or similar material to what you are buying, or from somewhere else? Several truckloads of hay from different origins landed in Gippsland in 1997 using the same FEEDTEST analysis! Also many bales of rubbish were accompanied by analyses indicating at least average quality hay. Was the silage sample taken from the bales that you are buying, or from somewhere else? How variable is the silage material in the stack being tested? Was it a grab sample from a feedout cart or pit face, or was it core sampled throughout the stack? How healthy was the sample by the time it arrived at the laboratory for testing? Did it sit in the ute for 2 days before posting? Did it sit in a post office over a weekend? How well was the bag sealed? How much air was excluded from the bag? These result in deteriorated silage samples resulting in decreased quality and dry matter content. Was the sample for the silage taken at cutting(incorrect), baling(incorrect), or after it had undergone the ensiling process(correct)? The fermentation process actually utilises some sugars and proteins so that the silage quality will be slightly lower than the quality at baling. Sampling for silage should occur at least 3 weeks after harvesting for stack silage and after 1 week for baled silage.

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Feed analyses may not show up mouldy bales unless the areas actually sampled were mouldy or deterioration was well advanced.

Both fodder purchasers and suppliers must build a rapport and trust with each other so that each is confident in what the other party is requiring or supplying. Genuine dealings between both groups is the only way of weeding out "fly by nighters" out for a quick buck, and to avoid buying "expensive rubbish"!

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