Sand has been a long established system, with few supporters. Researchers haven’t discussed the use of sand to much extend, they have mainly limited their findings to; “sand is ideal for cows”. The factors related to this statement such as; labor, animal health and other economic parameters have been left out of the published findings. One thing that has been proven in practice is that once a system is chosen, the user will defend his choice from his perspective leaving no room for objective data to flow.

Introduction

Nowadays sand as bedding material is still a viable option when building new dairy cow housing. However there has been a lot of controversy about the use of sand as cow bedding material. When comparing sand with mattresses one should keep in mind that the comparison must be based on the latest information about the mattress systems and not with information on mattress systems from fifteen years ago (rubber granules filling).

The value of sand
According to Jack Rodenburg, users of sand as bedding find that one benefit of working with sand is a lower incidence of clinical mastitis caused by environmental organisms like E. Coli and environmental streptococci. The lower incidence of clinical mastitis lies in the fact that no organic bedding is used and thus opportunity for bacteria to manifest. This in contrary to a survey conducted in Wisconsin, where there was no difference in average SCC between herds using sand and herd using mattresses.

The value of total cow comfort

Some users also claim to experience, when switching to sand, that the somatic cell count (SCC) decreases. A published study compared three inches of sand, over clay, with a mattress; the cows preferred the mattress.

DLG (Deutsche Landwirtschaftsgesellschaft)
conducts research in order to certify mattresses and they concluded that cows lie 12-14 hours in free stalls covered with Agriprom Energetic® Latex mattresses. Sand does not necessarily make cows lay down longer. Research conducted at the University of Nebraska show that cows that rest 14-hours a day, give the most milk. They don’t waste time in the alleys. They entrust their lower legs and blood flow to the udder is better thus resulting in more time for rumination. A farmer with a crowded stable and little capacity in the milking parlor will sell himself short; cows will have to walk longer distances and wait for longer periods in standing position. All these aspects will lead to less ruminating time and thus less milk production. In this Nebraskan study, cows that were normally laying down 9 hours a day, where given 12 hours of rest; this resulted in a milk production increase of 4Kg per cow per day.

Over the years the quality of cow mattresses has improved, of course this is producer-dependent.
Aging showed that old top layers of mattresses became rough, uneven, and abrasive also the used rubber granules collapsed and became very hard. Another deteriorating aspect is that the impression and elasticity of those mattresses reduced to an uncomfortable level. The DLG report on Agriprom showed that the Energetic Latex rubber sheets under a flexible rubber top-cover give a much better and longer lasting comfort. DLG research concludes that these materials show little wear and the bottom latex sheet retains its shape and elasticity over the years. Experience shows that the use of sawdust in addition to the mattresses can be minimal and some even do without, just using some moisture absorbant like Staldren or Brize. Of course there are different qualities of sawdust thus resulting in different results. A thin layer of “bad” sawdust (not dry, wood particles, splinters, contaminated) can result in abrasiveness on any type of surface, which in turn can cause skin irritations.

For this reason good quality mattresses should only be used with a small quantity of high quality saw dust in order to generate premium results. In retrospect it isn’t a necessity from comfort point of view, to have sawdust as an addition to the mattress. The purpose of the sawdust is to merely absorb, which can also be improved by using barn hygiene product such as:
• Staldren
• Brize
• Mixture of one of the above with saw dust.

Investment and costs

Costs of sand-surface
• No need for a mattress and less use of concrete.
• The cost of sand in comparison with saw dust or straw will also be lower
• Higher logistics costs for sand
• Higher labor costs for handling the sand
• Higher mechanization costs
• High investment needed for processing manure with sand
• Investment in the separation and storage of manure and sand
• Increased and quicker concrete, machine and equipment deterioration
• High maintenance

Costs of cow mattress:
• Relatively lower investment for purchasing of mattresses
• Faster ROI (Return on investment)
• Save on saw dust
• Save on labor costs and time
Agriprom conducted its own research that resulted in the following; bedding material costs in sand box systems in comparison to cow mattresses are quit similar (keeping in mind that for the use of sand and spreading, one needs to have specialized machinery). Deep litter boxes have the highest bedding costs; up to four times higher than sand and cow mattresses.

Stall design and management
Stall design and management in a sand bedding setting require more detailed attention. Sandbox system are not recommended in combination with slats, this because the sand sinks to the bottom, making it difficult to remove and clean. The free-stall should have a curb of 1520cm with a rounded top edge and a 45-degree slope to the inside of the stall, to ensure there is always sand between the rising cow and the curb. For this reason the bottom of the box should always be 15-20cm below the curb to ensure a 15cm sand minimum in the stall. Most users refill as soon as the sand level is below 2.5-5cm. Stalls should be of standard width (according to Dutch concepts) from 115cm to 120cm. Most of the time there is no use of brisket boards and the neck-rail is adjusted at 122cm above the concrete curb. This results in a relatively low positioning of the neck-rail when the sand is added.

The lack of brisket board in this system lays in the fact that configurations change continuously.
Cows typically kick 20-25kg of sand per day out of each stall in a above-curb-level of the sand and 10-15kg of sand per day when below-curb-level. It is custom practice to fill the stalls with a skid steer, dumping one full bucket of sand per stall. In order to facilitate this, the alleys need to be wide enough for the machine to turn. Mid-size machines require at least 3m to turn. Machines need to be equipped with a relatively long bucket in order to cover the front half of the stall in order to avoid any additional labor interference. Sand is added every 3-4 weeks and at first instance at least 15-18cm above the curb. This because right after the refill cows kick the most sand out of the stalls. If the sand level is below the advised height it will get increasingly difficult to clean the stalls thus the refill and upkeep should be frequent. Even though the refills should occur every 3-4 weeks, the cleaning and upkeep should occur on a daily basis in order to maintain the comfort level. Because it is highly labor intensive to refill sand and keep it leveled, some farmers invest in mechanization of the process.

Mechanization doesn’t come cheap though; it can easily mean a 20.000-euro investment. It also means that the floors and slated gutters of the stable should be able to carry the 10-20 ton load of the machine. The up side of this investment lies in the fact that refill frequency can be higher thus resulting in more efficient use of the sand. A prerequisite of sand used in these stalls is that it should be clean and free of soilparticles. There should not be any sharp particles that can come between the hooves of the animals, thus resulting in injuries. Fine sand particles can get attached to the udders of the cows, which can easily be removed by using cow-wipes before milking. The use of sand also means that it finds its way into anything and does contribute to a faster deterioration of the equipment and machinery.

Manure Handling

Manure handling and separation is the biggest challenge on farms that use sand bedding systems. The simplest solution is a tractor-scraper. There is some more deterioration to the floor surface, but using a rubber scraper can prevent this. Mechanical alley scrapers will wear a track in the center of the floor where the cables or chains run. When laying the floor, a thicker layer of concrete in this area will prevent the pre-mature resurfacing of the cables of chains; still one must be prepared to fill the center groove every 5-6 years.
Most farmers with sand barns replace their scraper cables annually. In most cases their bad experience with chains outweighs the cost of annual replacement. The chains cause more damage to the floor and don’t outlast the cables in these situations. Rinsing of the floors requires a slope of 2-2.5% in order to keep the heavy sand moving in the rinsing liquid. One needs to realize that a 2% slope in a stable of 100m translates into 2m decay. Waiting areas will need to be equipped with a drain in order to discharge the water load. These drains or trenches will need to be cleaned manually to remove any access sand that settles inside. Tractors will be able to dump the manure and sand in the designated storage facility. However alley scrapers (and in some cases tractors) will transport the manure to a discharge channel in the middle or end of the barn. This channels will gradually reach capacity unless it is equipped with drainage system or another means of discharge; a chain system. Once again deterioration should be taken into account. A build in ramp in the channel can help of course, but to save costs, most users locate their storage facilities near the barns and ramp-up the storage and design the discharge channel to be wide enough to drive into it from the storage facility. There is a diverse range of suitable machinery for this concept, however sand and gravel specialized machinery is recommended. Systems to separate manure from sand are still experimental and expensive. Bigger companies and farms consider investing in the McLanahan separator, which works very well but is still expensive for the average farmer.
Research conducted by Agriprom in the Netherlands amongst users of sand in cubicles lead to similar conclusions:
• There are no differences in cell count
• Sand use is labor intensive
• Sand use requires heavy investment in both processing as well as maintenance

Conclusion
Sand, compost manure and deep litter all provide cow comfort, but no real benefits to health, hoof and leg problems, mastitis and somatic cell count in comparison to modern cow mattresses. In respect to resting time in the stalls, no difference can be demonstrated. These systems however require significantly more attention and labor. Some of the costs are still difficult to estimate, but keeping in mind that bedding materials like straw and sawdust are becoming much more expensive. The loose housing with compost bedding, even though animal friendly, does not seem to meet the environmental requirements due to the instability of the composting process under Dutch circumstances.

The comfort of the Agriflex® cow mattresses with Energetic®Latex has been extensively proven over the past ten years. The required daily resting periods of 12-14 hours have been proven in practice. There are no direct rivalry methods when it comes to user friendliness; this has been concluded from independent research. The Agriflex reduces labor significantly, because insertion of bedding in the stall, leveling out and evacuation of used and or packed material is eliminated. In addition to labor savings, the investment in equipment, measures for manure storage and composting or sand separation are lower if not required at all.

If you are looking for an uncompromised, environmentally friendly, low risk and labor-saving solution with low maintenance costs and a short pay-back period, Agriflex® is the solution. Installation can also be provided.

Ing. G.J. Staal Director, Agriprom bv
Sources: OMAFRA – Jack Rodenberg (Ontario Ministery of Agriculture, Food and Rural Affairs) May 18th 2009 Publication: OOGST, September 2003;
Boerderij, Maart 2010-10-14
Agriprom – internal research 2008
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