Stress management: Cow comfort

Ruminant Processing Articles >> Health and Welfare

Cow comfort is becoming an often heard phrase in today's industry trade papers. It's a means to describe relationship between the well being of the cow and the housing systems. Cow comfort improvement focuses mainly on developments in stall design to reduce diseases such as mastitis and lameness and boost milk production. However cow comfort issues can apply to other aspects of the housing system.

Lying Behavior

Cattle are typical of most mammalian species, requiring to rest in a lying position for a considerable period within any day to prevent fatigue. The amount of lying depending on the animals immediate environment, social position and output. Indeed some studies report that dairy cows show strong reactions to changes in environment which cause a decreases in lying time 18.

Why is Cow Comfort So Important for Productivity?

The amount of lying behavior has a direct influence on cow productivity, health and welfare. Investments in housing that improve cow comfort show measurable financial returns through increase yields and improved reproductive and longevity status. Increasing cow comfort reduces stress in cattle. Stress raises concentrations of the hormone cortisol which reduces the cows efficiency and depresses yield.

Rumination (cudding) is closely associated with lying as up to 70% of total rumination occurs when the cow is in the lying position. It is thought cows which are comfortable (ie. lie more) ruminate for longer and increase the digestibility of the forage ration. Increased rumination also promotes a more stable rumen environment which is associated with a lowered risk of diseases such as acidosis and laminitis.

Disease Risk

Lameness

Many upper and lower leg disorders are clearly linked to lying time. When an animal is lying, it reduces the time spent with its hooves contacting a solid surface which in turn may have direct effects upon the development of hoof diseases such as laminitis.

Studies have shown that there are strong correlations between the incidence of foot lesions and lying time 10,15. There is some evidence that cows which lie down for shorter periods are more likely to become lame 5.

In a free stall facility if stall numbers are reduced to a 2:1 cow/stall ratio, lying time was reduced from 7-10 hrs to 5 hrs. The reduction in lying time was correlated with a significantly higher lesion score but lesions found in these animals were less severe than are seen in some herds, suggesting that lying time alone is not the entire explanation 10.

Stall size, amount and type of bedding material, spacing and height of partitions all affect lying time 5,13,18. Cows are discriminating: if stalls present problems in lying or rising or have an uncomfortable bedding material then the animal will either reduce lying time or refuse the stall altogether 5,11,12. Stall refusal has serious implications for increasing the risk of lameness by increasing walking and standing times 17. A recent study from BC showed that cows preferred to lie in deep bedded sawdust stalls compared to bare rubber mats and furthermore the amount of lying increased with increasing use of bedding material 16.

If cows are allowed access to lie in deep bedded stalls, the bedding material will dry any manure on their feet. This significantly lowers the risk of developing infectious foot diseases such as heel warts.

Lame cows have significantly reduced yields therefore by reducing the incidence of lameness in herds there will be a dirt benefit to productivity and therefore profitability.

Mastitis

Bedding material both type and quantity is extremely important in the development of environmental mastitis cases. Cows require adequate amounts of bedding to remain clean and above all dry. This greatly lowers the risk for coliform mastitis. If bedding is not removed on a regular basis (preferably daily) then bacterial numbers in the bedding increase directly increasing mastitis risk.

Many producers worldwide are reporting great success with sand bedding. Sand is inorganic and bacteria have less chance to grow in the stall therefore mastitis risk is greatly reduced 7. As a side benefit, sand stalls can conform to cow shape, reduce impacts during lying and improve footing when the cow rises 7. All these factors increase cow comfort considerably. Slope will affect the degree of drainage of wet material from the bed. Slope need to be more than 1% but not more than 4% to maintain a comfortable lying position for the cow.

Injuries

Neck hock injuries are common in herds with badly sized or improperly designed stalls. These types of injuries place considerable stress on cows and reduce yields. A well rested, uninjured cow will produce more milk than a cow in less than desirable stall conditions

Indicators of Cow Comfort

Ideally cows should be either feeding or lying. If cows spend a lot of time standing idly and not feeding this could be an indicator of stall conditions that are deterring cows from lying.

Observing your cows in the barn can determine if the following behaviours occur:

Are some stalls always avoided and empty?
Are cows mostly standing half in/half out of stalls?
Do cows make abortive attempts to lie?
Do cows lie in alleyways or backwards in stalls?
Do cows sit back on their haunches like a dog?
During quieter periods in the barn (ex, 2 hours after evening milking) are there more than 30% of the cows not lying?

If any of the above behaviors are seen then a problem exists.

Cows should be provided with a lying area which does not interfere with the transition from standing to lying and vice versa. The area should be bedded and more stalls should be provided than there are cows. Cows need adequate lunge space to throw their heads forward before repositioning their front legs into a kneeling position and rising.

Stall Dimensions

Dr. Neil Anderson a veterinary investigator with OMAF has done considerable work on the correct stall dimensions for both free and tie stall cows. Cows need stalls to provide adequate lunge space dependant on the size of the largest cows in the herds.

Dimensions can be found at the OMAFRA site and is an excellent guide if you are planning to upgrade stalls.

Other Considerations

Overcrowding

Overcrowding is probably the major factor which affects behavioural risk factors for lameness diseases and traumatic injury due to slips and falls. If cows are housed with high stocking densities, activity levels are altered and cows are forced to invade the 'personal space' of their immediate herdmates, increasing the underlying incidence of aggression 3,4,12. Crowding in narrow passageways or by herding to and from yards increases aggressive confrontations as subordinate cows cannot express submission 2. Such confrontations result in mechanical damage to the feet especially if the surface is abrasive 4,11,17

Cows should not be rushed to and from milking or to any other area of the barn Adequate space is vital especially in areas where cows congregate such as water troughs and feed bunks. Providing adequate access will allow more cows to feed and lie simultaneously and reduce the amount of time cows spend being unproductive such as standing idly.

Walkways and Cow Locomotion

A certain amount of locomotory behavior is necessary for the cow to perform normal maintenance activities e.g. visiting the feed area9, and to satisfy a motivation to explore their immediate environment - a behavior known as patrolling 19. Distances walked daily can influence the risk of lameness. Long distances walked by the animals to and from milking together with wet conditions and abrasive surfaces were strongly associated with an increased incidence of lameness 6. The greater the walking distance on concrete floors the greater the risk of lameness due to hoof abrasion and traumatic damage to the limbs caused by slipping 8. Freestall dairy cows spend around 5% of their daily activity walking 20. Actual distances walked, however, are small compared to distances walked on pasture: ranges between 400 and 2000m have been reported for housed cows 8,9,13.

Increasing the softness of flooring with durable rubber mats are a viable options. Cows have better traction and increase walking speed but correspondingly have lower incidences of slips and falls 14. Producers should consider alternatives to concrete but at the very least groove smooth walkway surfaces and prioritize cleaning alleyways.

Feeding and Water Areas

At pasture, food is widely dispersed making it impractical for cattle to defend it as a resource. In contrast during housing, feed is offered in a limited space, resulting in increased competition and disputes over access to this feed 11. Studies showed that peak aggression and activity coincides with the initial provision of fresh feed during the morning 12. Subordinate cows such as heifers are less able to signal submission by escape behaviour 2, leading to confrontations, which may in turn have caused damage to the feet by traumatic shearing injuries, or exacerbate the severity of disease already present.

It is therefore important to not only provide cows with adequate feed for production but distribute the feed over a large enough area to ensure cattle have free access to feed without intimidation. Ideally cattle should have a minimum of 2.5 feet of bunkspace in a free stall barn. Feed should be pushed up regularly to prevent cows from stretching to reach the ration. By overextending, especially on slippery manure covered concrete, cows are prone to slip leading to injuries of the front legs in particular. The height of the feeding rail is also important as it should not place undue pressure on the neck of the animal nor restrict access to feed. If many cows in your herd have hairless calloused areas on the neck then consider the physical restraints at the feed area. Allowing cattle maximum access to feed ensures that production is not restricted.

Water is extremely important to milk production. In frees stall conditions one trough for every 25 cows is recommended. Troughs are best sited in wider areas of the housing such as crossways and entrances to the collection yard. In tie stall situations where the waterer is shared it is best not to place heifers and older cows together as there will be dominance issues over access to water leading to lower water consumption rates in heifers. Waterers are also best placed at a minimum of 14 inches to prevent cows splashing excess water on the bedding during drinking.

Summary

Cow comfort issues are often ignored but then can have serious implications for herd profitability. The previous serves as an overview to some of the problems associated with managing cows within today's housing facilities. Cows will tell you what is wrong with the housing environment if time is taken to observe them quietly. Quality milk production should include a component of animal welfare which should not been seen as a cost.

by Manitoba Agriculture, Food and Rural Initiatives

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