Welcome to The Dairy Mail

by Rykie Visser, Africa Development
and Sales Manager: Agrinet

There is no doubt that proper rest areas and proper bedding for dairy cows could ensure higher production levels and could also mean lower somatic cell counts. But there are a number of important aspects to take into account.

Lying down – duration and frequency
Under ideal conditions, cows lie down for approximately 14 hours per day. During that time, they sleep for only 30 minutes. When the resting surface is not sufficiently comfortable, cows will reduce their rest time. If cows are unable to lie down when needed, they will stand for too long and this will change their natural behaviour cycle. Once cows are finally down, they will lie down for too long. Cows will then eat and drink less, go to the feed area less frequently and consequently consume less dry matter. If cows consume fewer meals during the day, the meals they eat will tend to be larger and the cows can get into a yo-yo type feed intake pattern.

The lying periods of cattle fit in between the periods of feeding and standing. A lying period typically lasts one and a half to three hours. In other words, a cow stands up and lies down many times per day. During the long lying periods in the middle of the day or during the night, the cow rises, stretches, and lies down again immediately – usually on her other side. Cattle spend more than half their lives lying down.

A dairy cow lies down and rises around 16 times every day, which means between 5 000 to 7 000 times in a year. Among other things, the lying-down time and the number of lying-down periods depends on the age, heat cycle and the state of health of the cow. The weather, quality of the bedding, type of housing and the number of animals per square metre also influence the lying-down time and the number of lying-down periods.

Cows need to lie down. Reduction in lying-down time reduces milk production. Lying down is important because:
• the cow rests and ruminates when it is lying down
• the cow’s hooves rest and dry off
• there is more space for other cows to walk around in a shed
• blood circulation through the udder increases by up to 30%.

A comfortable bedding area will secure proper rest time for the cow

Lying down
Each time the cow lies down, she puts about two-thirds of her body weight (depending on breed and lactation stage between 500 and 650 kg) on her front knees. Her knees drop freely to the floor from a height of 20 to 30 cm. It is therefore very important to have good quality bedding so the cow can painlessly lie down whenever she wants to. A very easy check is to look at how fast a cow lies down in a cubicle. If she takes longer than five minutes on average, you should check the cubicle and bedding for reasons why she doesn’t lie down immediately.

Standing up
An important consideration is lunge space. A cow should lunge forward in the stall when she stands up. If this is impossible, a cow should at least have enough space to lunge to the side of the stall. If adequate lunge space is not available, cows will have difficulty in rising and may eventually stop using the stall.

Space requirements
To rise or lie down, the resting area must provide cows with the freedom for vertical, forward and lateral movement without obstruction, injury or fear. A rising motion includes the freedom to lunge forward, bob the head up or down, and stride forward. A resting motion also includes the freedom to lunge forward and bob the head.

Cubicle design
There are many different stall designs, most of which will work well. It is very important to observe the cows’ reactions to stalls. Don’t just get out the tape measure. Watch cows get up and down in the stalls. Cows should get up the same way in a stall as they would outside on pasture.

Cows need to bob their heads down and forward so that they can shift their weight from their back legs when they stand. In a stall, cows can either bob forward or to the side. It is difficult to give specific measurements for cubicles because of the size differences between dairy breeds. It is normally recommended that cows have at least 47 cm of head space and 168 cm of space for their body. On top of that, lunge space must be provided (at least 30 cm). Therefore, the stall should be 245 cm long unless cows are able to lunge forward into the space beyond the stall – such as into an opposite cow stall, alley or outside of the shed.

If a stall is barely 215 cm in total length, it must allow the cow to lunge sideways as she gets up. Bending the bottom of the stall loop out of the cow’s way (either higher or lower) will allow cows to lunge sideways.

Install a brisket board on the stall floor. Brisket boards should be 168 cm from the stall curb and 15 to 20 cm high with a 60° angle. They help keep the cow from crowding to the front of the stall, brace her as she gets up and keep the stall cleaner.

Bedding
There are several critical factors that must be considered when planning free stall surfaces. The surface must be durable and easily maintained. It must be well drained and/or resilient to water. It should not be slippery and should give secure footing to prevent potential injuries. The flooring should be soft and comfortable rather than hard, cold and damp. The surface should be made of inert material so pathogenic organisms will not grow. The cost of the surface has to be considered relative to its potential for reducing or increasing animal injuries.

Bedding treatment
Bedding material must be kept as clean and dry as possible to limit bacterial growth. Organic bedding material should be replaced daily to limit the growth of bacteria in the stall and reduce the risk of udder infections from environmental pathogens. Certain organic bedding materials (sunflower hulls, straw, maize stalks, grain hulls or hard wood) support the growth of large populations of environmental mastitis pathogens.

It is important to use large particulate material, as these materials do not support the growth of bacteria as readily as fine particulate material. Research shows the importance of regularly renewing the bedding. When sawdust was added to cubicles on a weekly basis, coliform levels were very high. Levels declined when bedding was replaced daily. To keep a healthy hygienic environment for the cows, it is of utmost importance to keep bedding as dry as possible. Dry bedding means less bacteria growth and reduced risk of mastitis. In addition, dryer bedding will result in fewer flies, slip resistance and an odour free area.

Stock density
Stock density influences the lying-down time of dairy cattle. Research shows that overstocking reduces lying-down time. When the cows would normally be lying in a cubicle, they are forced to stand outside the stall. Cows are more likely to displace others from free-stalls or cubicles at high stocking densities. Normally dominant cows will displace the low rank cows, particularly heifers, so the low rank cows will reduce their lying-down time even more than the high rank cows.

Ventilation in resting area
A cow, which has inadequate fresh air, will not lie down readily because she can breathe better when she is standing. Therefore, it is very important to ensure that there is good ventilation in front of the cow stalls. Air movement is important to reduce shed humidity and heat. Condensation, cobwebs, the smell of ammonia, coughing cows and cows breathing with their mouths open are all signs of poor ventilation.

Humidity in cubicles
Humidity in the cubicles provides good conditions for pathogenic bacteria to develop. With good ventilation and frequent cleaning of the bedding, you can have drier stalls with reduced moisture levels. This can help to depress bacterial growth. Humidity in your shed can be easily seen as moisture on the walls or roof.

Fly control in resting area
Flies cause irritation and stress, creating a serious threat to the productivity of the dairy cow. Studies show that a tormenting population of flies can cause reductions in milk yield. Flies could also jeopardise your milk quality. The various bacteria and viruses they carry might find their way not only to the cows (leading to the spread of diseases), but also into the milk via clusters and liners. Reducing the fly population means less stress and less disease.

Ruminating during resting
A cow has to ruminate for seven to ten hours per day. Fifty percent of cows lying down must be ruminating – if not there is not enough effective fibre in the ration.

Resting to prevent lameness
Increased time spent lying down in a clean dry comfortable stall will potentially mean less time spent in concrete alleyways, which leads to cleaner, drier hooves. Cattle housed in wet, manure contaminated conditions are more likely to suffer infectious diseases of the foot.