Flooring

Flooring Types

The walking and standing surfaces that cows are exposed to between bouts of lying have a significant impact on their well-being, principally through an effect on their risk for lameness. The effect of the flooring surface may be mediated through limiting the duration of contact and the distance walked on the surface, and through properties of the surface that may cause trauma and wear to the claw.

Producers building new facilities are faced with two main questions regarding flooring:

1. How to optimize traction on concrete floors using texturing and grooving
2. Whether or not to replace concrete floors with rubber flooring

Concrete Flooring

Concrete is relatively cheap and durable for use in livestock facilities, but it is far from an ideal surface for cows to walk and stand upon, especially when it is covered with manure slurry. Concrete floors do not provide enough friction to allow natural locomotion behavior. The critical coefficient of friction for slippage by the cow is 0.4, while the recommended coefficient of friction required to provide traction as the cow begins to start walking from a standing start is 0.4 to 0.7. Most concrete floors have a mean coefficient of friction of around 0.35 – lower than that required by the cow for normal ambulation. As a consequence, it is common to see cattle slip and injure themselves on concrete floors.

Concrete is a critical blend of portland cement, sand, water and aggregate, and creating the right mix is a skilled task requiring excellent operating crews. Choice of aggregate is very important. It should be washed free of impurities, and clay and finer aggregates are preferred over large rough aggregate. 0.5 mm aggregate allows cows to make comfortable long strides, while larger aggregate of 2.5 mm (and higher coefficient of friction) causes a reduction in walking speed due to a shortening of step length, making the material less desirable.

On large dairies with long pens housing a large number of cows per pen (e.g. 250 cows or greater per pen), and long transfer lanes to move cows to the parlor, a stronger, more durable concrete mix is recommended to maintain the integrity of concrete floors, avoiding wear and pitting that exposes aggregate and leads to increased wear of cows’ feet. In these situations, builders are constructing freestall pen alley floors with 4000 psi (30 MPa) concrete using a 6-bag mix (564 lb cement per cubic yard of mix or 256 kg cement per cubic meter of mix). 100 lb of fly ash per cubic yard of mix or 45 kg of fly ash per cubic meter of mix can also be used. In high traffic areas, such as transfer lanes and milking center holding areas, floors are poured with 5000 psi (35 MPa) concrete using an 7-bag mix (752 lb cement per cubic yard of mix or 341 kg cement per cubic meter of mix). The thickness should be a minimum of 4 inches (10 cm).

In order to further reduce the risk of slipping and injury, concrete surfaces should be textured or grooved to improve traction.

There are numerous grooving patterns, but the final product must strike a balance between providing enough grip to prevent slipping while not being so rough that it promotes excessive wear of the sole of the hoof.

We do not recommend V-shaped grooves. The edge provides less traction than a vertical groove, and the hoof wall can twist and shear if the claw enters a groove.

V-shaped grooves spaced too far apart (not recommended)

We also do not recommend cobblestone floors as the surface is usually left uneven between the grooves, and the grooves are too shallow to provide long term traction after a year or so of scraping.

 Cobblestone flooring has shallow grooves and uneven surfaces (not recommended)

The aim of any grooving pattern is for the cow’s foot to make contact with the floor over a groove wherever the foot lands. This will force the manure from the floor into the groove and facilitate contact between the claw sole and the concrete surface. As the claw slides to a stop, it will meet the sharp vertical edge of the groove providing traction.

Our recommended pattern is to groove alleys parallel to the feed bunk with grooves 0.5 inches (1.3 cm) deep and 0.75 inches (1.9 cm) wide, spaced 3.25 inches (8.3 cm) on center. Custom bull floats able to create this pattern are available from Comfort Hoof Care Inc.

Our ideal grooving with sharp smooth edges to grooves 0.5 inches (1.3 cm) deep and 0.75 inches (1.9 cm) wide, spaced 3.25 inches (8.3 cm) on center

In areas where cows must make sharp turns or in cross alleys with waterers that may become excessively wet and slippery, the pattern may be supplemented with an oblique groove to create a diamond pattern, spaced 4 to 5 inches (10 to 13 cm) on center. We do not recommend these diamond shaped grooves for the entire pen as this will lead to too much hoof wear. The side walls of the groove must be vertical rather than V-shaped, and we recommend leveling the surface of the concrete before using the float to create a sharp smooth edge to the grooves.

The flooring surface must be flat rather than convex between the grooves, and the edges must be smooth with little or no aggregate exposure. Floating and stamping are time sensitive and must be done when the concrete is not too wet (grooves tend to fill in and concrete sticks to stamp) or too dry (poor penetration and shallow grooves with aggregate exposure and bulging between grooves) by a skilled operator. Before the cows are exposed to the concrete, it is usually necessary to grind the floor to smooth off the finished surface, removing all sharp and broken edges. While bull-floating wet concrete is cheaper, some producers choose to cut grooves in formed dry concrete. A similar pattern is recommended.

For existing floors that have worn smooth or where the aggregate has become exposed, texturing is an excellent option rather than re-grooving, which tends to erode the flat stable standing surface available to the cow. There are several different options such as AGRI-TRAC, which removes the entire one eighth of an inch (0.3 cm) of the existing surface and leaves a fine ribbed pattern spaced about one quarter inch (0.6) apart. Another similar re-texturing option is provided by TrakRite. TrakRite has created a machine, the TR-330, which can provide texturing or cut deep grooves in already poured concrete by using a “bullet cutter.” Re-texturing should be differentiated from scabbling, which is only done in wide shallow grooves, leaving parts of the flooring untouched. However, this is not recommended.

Rough flooring with exposed aggregate caused by erosion

Rubber Flooring

The compressibility of the floor, independent of roughness, reduces the risk for slippage. This may better explain the improvements in gait observed when cows walk on rubberized surfaces. The coefficient of friction for rubber floors ranges from 0.46 to 0.61 with a mean around 0.5. Compared to walking on concrete, animals walking on rubber have been shown to slip less, take longer, fewer strides, and increase the speed of walking. For this reason, it has been commonplace for rubber flooring to be used to facilitate the movement of cows between pens and the milking center. Cows receive two benefits from having rubber flooring between pens and in the milking center – reduced wear and concussion. Reduced wear helps decrease the number of new cases of lameness, and reduced concussion makes it easier and less painful for lame cows to move.

With the obvious success of rubber in transfer lanes, many producers have installed rubber flooring in the freestall pens and elsewhere, such as in holding areas and parlors. However, evidence showing that rubber flooring in freestall pens has a significant beneficial effect on lameness is lacking. Across multiple studies, effectiveness is mixed.

Many of the studies examining the impact of flooring on lameness demonstrate an interesting interaction between the flooring and lying surface. The reason for this may come from an understanding of the impact of rubber pen flooring on time budgets. In studies conducted with mattress freestall housing, the addition of rubber flooring resulted in increased time spent standing on the rubber alley floor, less time lying in the stalls, and an increased likelihood of alley lying – changes that are more likely to be detrimental to claw health. Therefore, the addition of rubber flooring to a pen with uncomfortable stalls cannot be recommended at this point.

Based on the available research at this time, the Wisconsin Blueprint recommends limiting the use of rubber flooring to certain high-risk areas of the barn.

In order of importance, rubber floor surfaces could be provided in the following locations:

1. Transfer lanes – where cows are walking more than one barn distant from the parlor
2. Holding areas – where cows are forced to stand for an hour or more
3. Parlor return lanes – where excessive slopes >2% may enhance wear
4. Parlor platforms and exit areas from rotary parlors – where cows make sharp turns

Rubber may be provided along the feed bunk in the pens only when stall design has been optimized. Rubber in feed alleys may have a negative effect on daily standing times if the stall design is compromised. Stall design should therefore be optimized before considering the expense of rubber in feed alleys. Barns with slatted floors will require rubber flooring to help reduce hoof trauma.

When choosing a rubber floor, it is important to pay particular attention to its compressibility since it is this property that will reduce the risk of cows slipping on the flooring. Hard rubber belting products with a high percentage of recycled rubber tend to be firm and less compressible, which leads to increased risk for slipping if used on sloped floors such as parlor return lanes. These products may however be suitable for level transfer lanes where they will help reduce hoof wear.

Products with a greater percentage of natural rubber will tend to have greater compressibility and be less likely to cause slipping. These products will be better suited for holding areas and sloped return lanes, but they will suffer from more rapid wear, requiring more frequent replacement.