Eye on Europe: Straight tails - the first sign a piglet is bored

Monday, April 5, 2010

After years of monitoring piglet behaviour, a Dutch researcher has found that when there's no curve in the tail, there's trouble ahead.

by NORMAN DUNN 

One scientist who's spent more time than most observing piglet tails – and whether they're curly, in continuous movement, straight along the back or down between the legs – is Johan Zonderland.

He's a member of the Animal Sciences Group at Wageningen University in the Netherlands, and he and his team have discovered that the way a piglet holds its tail indicates whether it's bored or not. And (as every hog farmer knows) when a piglet is bored, that's when fighting and biting starts in the pen.

The work that led to the classification of tail positions started several years ago when Zonderland was involved in assessing what materials could be added to weaner pens to stop boredom and thus injuries from biting.

Back in 2001, a European Union (EU) directive had already been issued urging hog keepers to offer materials in hog pens that would allow the animals to exercise their natural play and rooting instincts. In the Netherlands, nine senior hog welfare experts were asked to decide what the best materials were from a choice of 64. Ideas that fell by the wayside quickly were simple rubber mats and bits of rubber hose. Some farmers had even tried mirrors on the pen walls.    Much more realistic, and winning top scores, were such ideas as regularly-added straw with chunks of fodder beet in it, or even whole bales of straw left in the pen for the weaners to play with. Loose peat from a dispenser also got high marks.

It was at this time that Johan Zonderland and his colleagues started paying more attention to the way piglets held their tails. By 2004, this researcher had determined that a curly tail basically meant a contented piglet. In pens without any material to keep them busy, Zonderland noted that the animals' tails tended to straighten out. At that time, he reported: "Two to three days before piglets start biting each others' tails, they straighten their tail and then hide it between their hind legs."

Even then, this was more than just a theory. Zonderland's team had observed more than 1,000 piglets that had not had their tails docked. The outcome was clear. Where piglets had play material in their pens, their tails stayed curly. Where they had none, or the wrong materials, boredom quickly set in, tails grew straighter and, within three days or so biting began.  

Now, the work has been put on an even more scientific basis for a report in the journal, Applied Animal Behaviour Science. In more studies with piglets from four to 10 weeks old, it was noted that a certain number carried their tails straight and tucked down between their legs. Just three days later, 25 per cent of these animals had serious wounds on their tails and a further 11 per cent of the "straight tailers" had bite marks in other parts of their bodies. 

Zonderland is now pretty certain that straight tails are the first sign of boredom and that farmers can take positive steps to avoid injuries by reacting quickly and adding play material to pens. Even throwing more straw into the affected pens twice a day, or something else that the animals can fool around with, can stop a tail biting outbreak, he feels.

"It is much more difficult to stop the tail biting once the tails are wounded and there is blood on them," he says.

Some unexpected findings on what's the best weaning age 
British hog producers often claim they lose income through being forced by U.K. legislation to wean piglets at 28 days or later instead of 21 days, for example. But new calculations by the British Pig Executive (BPEX), the country's swine sector representative organisation, indicate there's sometimes more money to be made with late weaning – and that early weaning can leave much less of a margin.

"What is often missed in calculations," explains BPEX's Dr. Mike Varley, "is the negative physiological effects of early weaning."

According to BPEX, the disadvantages of weaning at around 21 days include more complicated herd management, higher building expenses, an increase in the weaning to oestrus period, reductions in herd conception rates and reductions in average litter size.

"Mathematically, the early weaning route may look like the best one," says Dr. Varley.

"After all, this course gives more litters per year."  But then there are the above-mentioned negative factors to take into account. And naturally slaughter hog and feed prices at the time all play a role.

For instance, BPEX fed all relevant information – including the negative news – into a computer model in summer 2009. The result was that, with 33-day weaning, the cost per kilogram weight gain in the litter was C$0.61 compared to $0.73 for 21 days. And, again using 2009 feed prices, gross margin per sow/year with weaning at 21 days was the equivalent of $89.50 average, while in a herd weaning at around 33 days the gross margin was $315.  And the same advantage for later weaning was shown with gross margin per hog produced: $22 against $20.

Dr. Varley admits that it is not easy to change a weaning routine on a working farm. But he suggests that the weaning age should be reviewed at least once a year with a computer program to identify if more than 28 days might be appropriate when all costs, and naturally pork price, are taken into account.

"Aim for medium- or long-term changes in weaning date based on computer analysis – not simple pig per sow production," he advises.

Rubber matting helps prevent hoof and leg injuries
Rubber matting on sow service centre floors reduced hoof and leg injuries by over 30 per cent in a German trial. Stiffness in walking was also less evident where sows were given rubber matting instead of bare concrete slats to lie on during their four weeks in the service centre.   

This kind of soft flooring is already giving better performances with growers and in-pig sows. But now more attention is being given to the sows just out of the farrowing department and getting ready for service. The reason: by end of 2012, all pregnant sows in Europe will have to be loose housed in groups.

Experience in the many farms that have already switched over from stall and tether systems indicates that loose housing demands a high level of hoof fitness and that the phase when sows are grouped for insemination offers an opportunity to get them off to a good start for the gestation period.

"Good hoof health is a basic requirement for high fertility in sow production," reports Dr. Stephanie Knoop from the Boxberg Centre of the Baden-Württemberg State Pig Breeding Institute. Here, a trial compared sow hooves after four weeks in a service centre with rubber matting on the lying area and one with conventional concrete slats.

Dr. Knoop split a randomly chosen group of 28 sows between the two floorings. The rubber matting had openings cut through to correspond with the slat gaps below so that the flooring remained just as clean as before.

Sows were inspected for differences between inner and outer claws and injuries to dewclaws, including cracks in the horn. Hoof sidewall damage was also noted, along with scraping and thickening of lower leg skin. Lastly, any stiffness in the gait of the sows, or lameness, was noted.

The sows were inspected when coming into the serving centre at Boxberg, then looked at again two weeks later and finally checked on leaving the centre after a further two weeks.

Dr. Knoop says the results, even allowing for the very small number of sows taking part in the trial, showed that rubber matting in the lying areas of the service centre had a positive effect on sow hoof health.

Just how positive was highlighted at the final inspection where 75 per cent of the sows in the service centre with the rubber flooring had no skin scrapes, worn or split horn material on the outer claw. This applied to only 42 per cent of the sows on bare concrete slats. As for stiffness in walking, 86 per cent of the rubber mat sows showed no difficulties in this department by the end of the trial period, while 25 per cent of the animals on bare concrete slats had some sort of problem with their gait. Interestingly, Dr. Knoop and her team noted some lameness during the second inspection, but this symptom had completely disappeared in both groups during the two last weeks in the service centre.

Why didn't rubber matting do away completely with at least some of the hoof problems in this trial? Dr. Knoop points out that only the lying area of the trial was rubber matted; the remainder of the flooring was bare concrete. She reckons that the main reason for at least some injuries was the simple fact that the rubber matted lying area was preferred by, and quickly filled with, dominant sows, leaving the others to lie on concrete.

The researchers point out that the coming of loose housing for all gestating sows throughout the EU (some countries such as Sweden and Britain have already made loose housing mandatory) brings completely different demands on the legs and hooves of sows. In free movement systems, there's naturally much more legwork as sows move between the lying area, the dunging section, feed troughs and watering points, and are involved in hierarchy struggles. This is mainly why it is felt that leg and hoof health has a new importance with swine which means more attention to softer and smoother flooring alternatives.

One producer's six-year court battle to survive
Just about every country nowadays experiences misunderstandings and sometimes downright battles between agriculture and a rapidly expanding rural population. Sections of this non-farming population reject every aspect of food production on the land and show an increasing lack of understanding for farmers and their businesses.

It's certainly true that there's a case for careful consideration every time a new large-capacity hog barn goes up in a populated area. But where farmers take every precaution to avoid confrontation and are still robbed of their right to make a living, it's time to take a stand and fight back for survival.

This is what farmer Frank Grimm from north Bavaria thought, too. But it has taken six years of court appearances, during which time he was once forced to stop buying in weaners altogether, before he eventually won the right to continue his hog feeding enterprise.

Grimm's feeding barn has just 960 feeding places. But part of the local campaign against the unit included a leaflet distributed to all households in the district describing his lone barn as "a hog feeding factory." Here are the facts:

*    2002: Frank Grimm applied for building permission. He undertook to take special precautions to keep smell down, including putting chopped straw matting over the manure silo. The nearest dwelling house was 190 metres away on an industrial estate, the nearest village even further. The finished building was officially approved. Total cost: C$550,000.

*    Fall 2003: With the building completed and the first hogs in the barn, complaints of "smell nuisance" began to come in from the village. Within four months, after threats of court action to force him to stop production altogether, the farmer altered his feed rations with, among other measures, lower crude protein content in efforts to reduce manure smell.

*    2004-2009: Continual disruption and legal moves to stop production on the Grimm farm.

*    Fall 2009: One neighbour managed to secure a court order stopping all further hog production on the farm. Grimm had to cease buying in weaners and was winding down the business. During that time, no fewer than five independent expert witnesses were called in by the farmer with the help of Germany's largest representative body in this sector, the Interest Society for German Swine Producers (ISN).

*    November 2009: A new case was opened and all the expert witnesses testified that Frank Grimm's hog enterprise was up to modern standards and that emissions were completely acceptable under EU rules and local bylaws. These experts, plus lawyers working on behalf of the farmer and the ISN, managed to convince the court to review the situation and, by December, the judge in charge had reversed the original decision. Grimm once again began to fill his barn full of feeding hogs.

*    January 2010: Unbelievably, another judge demanded a further check on emissions from the farm, although there's been no stocking or feeding policy change since the November 2009 decision.

Now there are two cases scheduled around the beleaguered hog barn. One neighbour is appealing against the November judgement and Frank Grimm is, in turn, suing him for lost income during his forced depopulating. BP