19 September 1997

WHYCOMFY COWSLL DELIVER

Think cow comfort and hopefully your cows will think of you, says Roger Blowey of the Wood Veterinary Group, Glos

LOGIC must surely tell us that comfortable cows are likely to be more productive.

But maybe the converse is more easily understood – uncomfortable cattle are likely to be stressed, more susceptible to a range of diseases and will, therefore, be less productive.

Calving is undoubtedly the main stress in the cows calendar. Those old enough to remember will have seen the rings on a cows horns, one for each calving. When horn growth is rapid – for example between the first and second lactation, or when the calving interval is extended, due to a failure to conceive – then distance between the horn ring is increased. Horn rings are a clear indication that calving is a big stress, even for low-yielding beef suckler cows.

Clearly, there is little we can do about calving itself, but we can minimise the effects of other stress factors. Ideas to consider include cubicle comfort, ample loafing area, adequate feed space, separate heifer groups, extended calving intervals and better cow tracks.

Cubicle comfort

Many producers have improved the dimensions of their cubicles, often providing extra forward lying space, and they may have designed partitions to minimise trauma. But do we always pay sufficient attention to bedding? Mats certainly help, but nothing can beat a thick bed of deep straw, and presumably this is why incidence of lameness in straw yards is so very much lower than in cubicles.

When a cow is rising, she first stands on her two hind legs, with her weight on both knees. She then transfers maximum weight on to one knee while she brings the other front leg into the standing position. It is the front of the cubicle, therefore, where the bedding is so important.

Concrete palaces, where bedding is a thin layer over a concrete base, are simply not adequate. Straw is scraped away by the first cow which stands up and certainly does not produce good comfort. Individual straw yards, one for each cow, are the answer to comfort. Judicious use of lime and regular re-bedding of the rear of the cubicle should minimise mastitis.

Loafing areas

As well as being able to lie down, the freshly calved cow needs enough space to be able to walk around freely. Walking is an important mechanism for pumping blood from the foot back up into the leg.

When blood is allowed to "pool", the tissues can become stagnant, the horn produced is of poorer quality and the foot is even more susceptible to bruising. The classic bruise occurs between the pedal bone and the horn of the sole, producing the typical sole ulcer. Damage to the tissues has been so severe that total disruption of horn formation has occurred. Healing will be slow and so the application of a Cowslip, or a similar device, is essential if that animal is to remain reasonably productive.

Ample loafing areas are also important for heat detection and conception rates. Animals which are tightly packed into a dark building, with blind-ended passages, where aggressive interactive contacts will be increased, are clearly less likely to think about mounting one another and less likely to conceive. When they also have bad feet and a sore abdomen caused by dietary acidosis, it is surprising that any of them get pregnant. A good airy, but unexposed, loafing area with escape routes for heifers works wonders.

Adequate feed space

It is the freshly calved heifer that causes most concern. When she has to compete with the rest of the herd in a limited feeding space she may spend longer standing waiting for her turn to feed, which leads to bad feet. She may also have to make sudden turning movements to avoid high-ranking cows – causing foot difficulties again – and she may end up mainly eating parlour concentrate because she cannot gain access to good quality silage. This can lead to rumen acidosis with a consequent increase in health problems such as displaced abomasum, ketosis, poor fertility and bad feet.

A separate heifer group is ideal. A small but increasing number of dairy farmers are now housing their heifers on straw yards for the first one to three months after calving. Their experience is that the heifers milk better, that there is less lameness and, perhaps most surprising, that cubicle acceptance is better after a period in straw yards than if heifers are introduced into cubicles immediately after calving. Again, this indicates calving is a greater stress than is allowed for on many farms.

Extended calving intervals

This will not appeal to everyone, but if you have an all-year-round calving pattern and high yielding cows, then extended calving intervals may be worth considering, at least for first lactation animals. They have flatter lactation curves and are more likely to continue milking for an extended period.

Calving is obviously associated with a wide range of diseases: Retained placenta, mastitis, ketosis, displaced abomasum, lameness, milk fever and nerve damage are just a few of the common examples. Even delaying service to 100 days will allow heifers some extra time to recover and if it improves overall longevity, it must surely be worth consideration.

Comfort outdoors

Excellent work by dairy consultant John Hughes on the construction of cow tracks has certainly improved cow comfort. The importance of cow tracks has perhaps been further increased by recent reports of a new condition causing lameness in dairy cows, namely haematoma (blood blister) in the heel.

This condition is also a result of trauma and all cases which have been reported occurred in the summer, when cows were walking along rough tracks. In the early stages haematomas do not cause severe lameness, but those which develop into abscesses can be quite painful.

Flints and small stones are often blamed as a cause of lameness when they penetrate the white line towards the heel. But how often do you see this in beef animals walking along the same track? The answer is, obviously, never. Perhaps it is not the flints which are the primary cause of lameness, but rather the effects of calving and then our management, feeding and husbandry of the cow which so weakens the white line that it allows flints to penetrate. Cow comfort is clearly equally as important in summer as in winter.n

"Individual straw yards"… deeply bedded cubicles such as these are ideal for improving cow comfort.

Sole ulcers are caused by a pinching of the corium between the pedal bone and the sole. A Cowslip applied to the sound claw reduces pain and will improve cow health.

Haematoma – blood blister – in the heel is a recently reported cause of lameness in dairy cows.

Small stones impacted into the white line. The primary cause is not the stone, but rather that the cemented junction of the white line is weak, allowing the stone to penetrate towards the heel.