Letter from Europe: Back to the straw-bedded barn for dairy cows?

Monday, December 1, 2008

by NORMAN DUNN

What's the best housing system for dairy cattle? This is the subject of arguments you'll hear raging in just about every country bar in Europe's milk production regions.

While stalls or free stalls have definitely won over a huge majority, there's still a staunch rearguard fighting for simple straw-bedded barns. In fact, a paper by the respected Scottish Agricultural College (SAC) indicates that there's a swing back to this for milking herds in that country.

Where there's plenty of room per cow – and the recommended minimum is 4.25 square metres of bedded area for a 500-kilogram animal – foot and leg problems and general cow health are claimed to be much better in simple straw barns than those with stall systems.

Scientists also say that there's much higher "behavioural synchrony" in straw barns – ethology-speak for herd members doing things like lying down to cud together. This immediately highlights one drawback to straw barns because cows also like to feed together, meaning competition for space at the trough and therefore more roughhousing there.

But, even with this disadvantage, deep-bedded barns will always have their followers, especially on mixed farms with small grains in the rotation and plenty of relatively cheap straw for bedding.

On most of the European mainland, however, stall housing is the norm, even though far away from being a complete success story.  One report finds that 88 per cent of stalls do not offer enough comfort for cows and heifers. Lameness and hock injuries are prevalent where "lunge area" (forward movement space within the stall when a cow gets to her feet) is too small. Also very obvious in all countries is that cows in deep bedding tend to be much cleaner than those kept in stall barns.

One of the main problems is that 50 years ago, when stalls were introduced on most European farms, they were built to last. Many barns haven't changed, but dairy cows certainly have. Holsteins now tip the scales at 200 kilograms and more above the liveweights of Ayrshire, Friesian, Normande or Danish Red cows back in the 1950s and '60s.

A recent survey of 70 dairy farms with stall housing in France finds that most stalls are too narrow for modern cows and very often too short as well. But even on farms with the latest stall designs, the survey notes that there is still not enough space for cows to get to their feet without banging into part of the structure. In southwest Germany, a similar survey amongst newly-built cubicle houses found that 60 per cent had serious faults in design!

So have stalls anything going for them at all when it comes to cow comfort? Part of the answer to this question takes us back to Scotland again. There, it's pointed out that, where stalls are roomy and well-designed, and where they offer the kind of soft, dry bed achieved by comfort mattress and additional bedding, cows actually lie longer per day than in straw-bedded barns.

German research also stresses that there must be room for "behavioural synchrony." But if the whole herd needs room to lie down and cud together, this means a stall place for every cow. If this is really the way ahead, then it just goes to show how wrong some stall house layouts are, with space for as little as 80 per cent of the herd to lie down at the same time.  

Comfort therefore seems to be the missing factor in bringing cow health and performance up to straw-bedded barn standards. There's certainly no lack of interest amongst European farmers in improving this aspect of their stall housing.

It's one reason why one of the most respected researchers in this field, the University of British Columbia's Prof. Marina von Keyserlingk, was main speaker at the European Dairy Farmers' club congress during EuroTier, the world's largest livestock management exhibition in Hanover, Germany, this November.

Von Keyserlingk emphasizes that mattresses on their own are often not enough. But when "softened" with sawdust, they can encourage cows to lie much longer in stalls. Results from one trial indicate that the right level of sawdust on the stall mattress can lengthen average lying time in a herd from just over 11 hours to almost 14 hours in a day. And that cows taking the weight off their feet for that extra time can produce up to 25 per cent more milk. BF

Norman Dunn writes about European agriculture from Germany.