More milk from comfortably housed cows

A cow has six basic needs - space, light, water, rest, feed and air. Out at pasture this isn't a problem but when housed how can you be sure all your cows are getting enough of each?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Over 25 farmers joined Myerscough College organisers at Wycongill Farm, Bolton-by-Bowland in the picturesque Ribble Valley for this latest demo event, by kind permission of Malcolm and Stephen Leeming.

The focus of the day was cow comfort, both its importance in terms of production from an economic point of view, and the ways in which it can be improved. Obviously the term cow comfort encompasses a number of aspects and within the scope of just a few hours it was impossible to cover everything, so it was decided to concentrate on ventilation and cubicle design in particular.

What are your cows telling you?

Karen Lancaster from DairyCo kicked off with a short introduction to the cow signals principles. Cow signals is not rocket science – it is basically taking a step back to make observations about your cows and their body language  and then asking yourself why you are seeing such signs.

The needs of a cow

A cow has 6 basic needs as outlined in the cow signals diamond – space, light, water, rest, feed, air. When the cow is out at pasture these needs will be met, but it is essential that they are also met when the cows are housed and this relies on your housing design. Karen concentrated mainly on two aspects – rest and space.

The importance of rest

To put the importance of your cows achieving adequate rest into perspective, Karen told us that for every extra hour a cow lies down (up to 14 hours) she will produce an extra litre of milk. This is due to the fact that when she is lying down, 30% more blood will flow through the udder as opposed to when she is standing. It therefore makes financial sense to ensure that your cubicles are as comfortable as possible to achieve maximum lying time for your cows.

Click here to read an article written by Karen on the basic principals of Cow Signals >>

Practical cow observation

Karen took a group of farmers into one of the sheds at the farm where the dairy cattle are housed and asked everyone to have a quick look around and observe the cows in this environment. This was a particularly useful exercise as the host farmers are currently building a new shed to house the dairy herd and so any problems highlighted by the cows in old building can be rectified in the new one. 

• Light – like many old farm buildings the shed is quite enclosed with a low roof. Any roof lights tend to be small and dirty so don’t let in much natural light.

 

• Space – passage ways are quite narrow and cow flow can be disrupted by other cows feeding. This was particularly apparent at the ends of the passages where water troughs were located – if one cow was drinking another cow could not pass behind so effectively blocking escape routes.

 

• Water – plenty of trough space available but issues with location as above.

 

• Feed – the design of the building was such that there were 2 rows of cubicles to one feed barrier. This allowed the cows sufficient trough space. However in buildings with 3 rows of cubicles per feed barrier this will not allow enough room per cow.

Karen suggested that if you are going to make simple alterations, such as increasing the height of the neck rail, then only do it in a small section of the shed. The cows will very quickly tell you whether or not the changes have been an improvement by the way they behave.

Ventilation = the movement of air through a building

Neil Roberts from Daleshead Vets and Matt Moore from RE Buildings took the other group into the new shed which is currently being built at Wycongill Farm to speak in more detail about ventilation. At 60m long by 35m wide the shed is large enough to accommodate all of the milking herd (which are currently housed separately in two sheds) with some room for expansion also.

Warm and humid

Neil began by putting into context just how important ventilation is when considering the health of your cows. A single cow can lose up to 20 litres of water vapour per day just through breathing out. In a herd of 100 cows this equates to over 2000 litres a day, and this does not take account of any other water lost by the cow through urine, faeces etc. This is a lot of moisture in an enclosed space and particularly in a shed which is densely stocked can quickly lead to a very warm, humid environment.

Disease spread

This kind of environment is ideal for bacterial growth, and diseases such as pneumonia and environmental mastitis will spread quickly under such conditions. Neil pointed out that pneumonia bugs are only spread by cattle breathing in infected air. The bug itself cannot survive for long once it has been breathed out into the atmosphere, but if the air in the building is stale and slow-moving and the building is densely stocked the chances are that another animal will breathe in these bugs and could succumb to the disease.

As far as pneumonia is concerned the most effective form of control is through ensuring there is sufficient exchange of air and the bugs are carried away out of the building. Hence good ventilation is vital in helping to reduce the spread of disease.

Fertility

Neil also commented on the effects of ventilation on fertility. Higher yielding cows tend to show signs of heat for a much shorter time than those with lower milk yields. As many farmers will know these cows also tend to exhibit bulling behaviour at night, when the building is cooler and quieter, and you are less likely to see them. In a poorly ventilated building heat will build up and effectively make the cows more lethargic and thus less likely to show signs of heat.

In addition to this cows will eat less when they are hot which may lead them into a negative energy balance after calving, the time when you are hoping that they will start cycling again. Less feed intake will also reduce milk yields by as much as 15%.

Air inlets and outlets

Matt went on to speak about how farmers can achieve good ventilation in their buildings by ensuring there are adequate air inlets and outlets. Air movement within a building is brought about when the warm air being breathed out by the cattle rises and leaves the building via the outlets at the apex, and then cooler air is drawn in from outside via the inlets in the side of the building. By a general rule of thumb the air inlet area must be at least double the outlet area.

Matt provided a handout for everyone with a couple of different scenarios for the new building whereby the air inlet and outlet areas were calculated based on the design of the shed, number of cubicles and potential stocking rates. Obviously the more densely stocked the building, the greater the inlets and outlets must be to achieve sufficient exchange of air.

Air exchanges

The number of air exchanges (complete circulation of fresh air) needed per hour to ensure that air is circulating sufficiently depends on the time of year – in winter housing a minimum of 4 exchanges per hour is needed whereas summer housing requires a minimum of 15 air exchanges/hour.

The new building has a light ridge supplied by RE Buildings which allows plenty of natural light to enter the building as well as allowing warm air to escape through the ventilating air ridges.

Feed space

Matt also spoke about how the feed space per cow must be taken into consideration when deciding the potential stocking rate of a new building. If the shed at Wycongill Farm was laid out with 3 banks of cubicles either side of a central feed passage it could accommodate 270 cows each with a feeding space of 0.45m.

However if the building was laid out with 3 banks of cubicles at one side of the feed passage and 2 at the other only 239 cows could be housed but each cow would have 0.51m feed space available. It is up to the farmer whether or not they would be prepared to compromise feed space and hence intakes and yield to fit more cows into the same space.

Cubicle design

Following a welcome hotpot lunch independent dairy consultant John Hughes spoke in detail about the importance of cubicle design for optimal cow comfort and lying times.

If you watch a cow getting up whilst out in the field she makes a total of 30 movements. However due to the restrictions imposed by a cubicle the cow can often only manage 12-15 when housed. The ultimate aim when designing a cubicle is to allow the cow sufficient space to lie down and get up in as natural a way as possible.

A cow will never lie downhill

Cows prefer to lie uphill so try to build your cubicles up at the front with a fall of approximately 5 inches from front to back. This also helps any urine to drain away into the passage. This can be achieved through building up a concrete “fillet” in the front of the cubicle which also acts as a brisket locator and stops the cow lying too far forward and dunging on the bed. Alternatively sand can be used to build up the bed and this provides a firm but soft surface for the cow to put her front foot onto when rising.

Bed length

Having sufficient length in the cubicle beds is vital for two reasons. First from the point of view of lameness – if a cow cannot stand in the cubicle with all four feet she will perch half in and half out with her back feet in the passage. This puts a lot of weight pressure on the back feet and over time will lead to weakening of the deep flexor tendon and the cow will be forced to walk on her dew claws. Also pressure on the back feet can lead to the development of sole ulcers.

Secondly a cow needs to be able to put her head and neck out straight to be able to cud effectively. If there is insufficient room in front of the cow she will be forced to bend her head around and this stops her cudding.

In addition to this the cow needs enough space in front of her to be able to lunge forward when she is rising, and if this is not possible she will show signs of “dog sitting”. Lengthening cubicles is not easy to achieve with those built against the shed wall, but if possible parts of the wall can be removed and a brisket board installed to effectively increase the length of the cubicle without having to physically extend the bed.

Keeping clean

Even if beds are cleaned and bedded regularly and kept spotlessly clean, the way in which the cow lies naturally with the udder resting on the back foot will mean that the teats are always dirty. The best way to minimise the risk of dirty teats is to keep all the passageways, and in particular the feed passage, as clean as possible through regular scraping. John suggested having a slatted channel in the centre of the feed passage with sufficient fall from the concrete on either side to allow the liquid to drain away and leave the passages much drier.

Bedding

John advocated the use of sand as the ideal bedding material. Obviously this is not possible in all situations as there may be issues with cost, slurry disposal, availability etc. Soft red sand is the best as it is not abrasive and it allows quick drainage of any liquid so the bed stays dry. However sand must be harrowed or raked every day to avoid problems with areas being dug out and puddling occurring.

Chopped straw on top of a mat or mattress is another good option, although the straw must be chopped finely to avoid any abrasive action which can cause lesion development.

Whatever type of bedding is used it is vital that sufficient cushioning is provided under the front knees and hock joints, as 80% of the cows weight when she is lying down will be supported by these points.

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