Crate-less farrowing that makes for contented sows
Tuesday, May 31, 2011
A German university research team has distilled the best features from a selection of European farrowing pen designs and produced a prototype that offers rubber-matted comfort instead of a crate
by NORMAN DUNN
Animal welfare pressure groups are increasingly calling for an end to farrowing crates on European farms and researchers across the continent are taking the threat seriously. They've already devised a number of innovative alternatives. In general, it's been found that a crate-less farrow pen appears to encourage a more relaxed sow, giving perhaps more milk. Certainly, taking the crate away also leaves less dangerous crushing zones for piglets. It also offers a system needing less cleaning time and therefore lowering costs.
The research team at Nürtingen-Geislingen University headed by Prof. Thomas Richter discovered a common problem, though. Most pioneering crate-less farrowing pens can't get away from the concept of some sort of restraint for the sow.
Using the carefully recorded results from over 180 farrowings through 14 breeding cycles in conventional crates as well as in a series of different "free farrowing" designs, Dr. Richter noted that piglet survival rates could be just as good without any barrier at all for the sow, although a protected creep area was always needed.
Especially where a limited amount of straw was available to the sow, no restraints meant the sow quickly established strictly separated laying/suckling and dunging/feeding areas, according to the Nürtingen findings.
A specially designed rubber mat for the lying area proved another positive addition to the concept. The Nürtingen researchers noticed that rubber mats in loose housing for groups of dry sows were always quickly reserved by dominant sows, indicating the perceived comfort of the mats. In the university's free-farrowing concept -- which quickly became known as the e-motion pen – staff had a completely clear view of the whole pen. Wherever there had been partial crates, or swing gates for occasional restraint, keeping an eye on all the young hogs at any one time wasn't so easy.
Cleaning the pens between each farrowing and suckling period was also much easier with the e-motion concept. This meant time and money saved and, in the university's experience, better hygiene.
Helping labour saving in this respect was the inclusion of a perforated floor for the feeding/dunging area. During the Nürtingen trials, some available straw caused no problems in the perforated area because the sow usually used this for nest-making on the mat surface, another aspect that kept the animal apparently at ease.
The heated creep area with built-in feed and water troughs seemed to offer enough shelter for the piglets and the final average weaners per sow figure was similar to the statistic from control pens with conventional farrowing crates. The weaned per sow average for the e-motion pen was better than free-farrowing concepts with varying degrees of sow restraint, according to Dr. Richter and his team.
Piglet survival measures with the e-motion pen also included boards bolted down one long side and the end of the lying area. These sloped downwards at 45 degrees with a 25-centimetre space from the floor so that piglets can escape under them.
No figures have been issued so far for piglet survival with the e-motion development, but Swiss figures comparing results from free-farrowing and farrowing crate systems in 60,000 farrowings put the number of piglets weaned per litter at exactly the same (9.6 per litter with 11 liveborn in each case). In the Swiss figures, one more piglet was crushed on average in the crate-less pens while one more death due to disease was attributed to the farrowing crate pens.
The e-motion pen is 14 per cent larger than conventional designs at 3.20 x 2.50 metres with the rubber-matted lying/nursing area 2.50 x 1.30 metres.
Using an electronic sow means an extra nine days to slaughter
It's not news that litters are getting steadily bigger. What is making headlines in Europe just now, though, is the speed of adoption for the artificial rearing concept known as rescue decks. These electronic foster-sows with automatic feeding systems allow litters to be slimmed down to a size manageable for the individual sow. Surplus piglets, after a day or two of mother's colostrum, are then transferred to the rescue decks where milk substitute and fresh water is available on demand for three weeks or longer.
But what effect has this form of artificial rearing on subsequent weight gain and carcass quality? One of Germany's largest agricultural research and training centres, Futterkamp LVZ in Schleswig-Holstein, took 52 Piétrain cross piglets reared in the artificial system and compared performance right through to slaughter with litter mates that had remained with their respective sows.
The rescue deck piglets performed fairly well during the trial. Stocking rate was a maximum 12 in each 1.5 x 1.0 metre heated rescue deck box (height 60 centimetres). An automatic mixer provides fresh milk substitute from two drinking bowls with built-in nipples. After the third week, the fostered piglets were transferred to a pen and weaned to solid feed. This meant that they joined their naturally raised littermates in the grower department after four weeks.
By this time, the daily liveweight gain (dlwg) of the Futterkamp rescue deck piglets had averaged around 100 grams less than the conventionally reared ones. This difference remained right through the growing period so that, when the hogs were penned in the feeding barn, the artificially suckled ones average a good three kilograms less liveweight than their littermates.
By slaughter at 164 days, the naturally suckled hogs averaged almost exactly 120 kilograms liveweight. The fostered hogs took another nine days to reach this weight. Average dlwg was 969 grams and 937 grams respectively. In this admittedly small trial, no significant differences were highlighted by the researchers between the two groups in general health, mortality or the carcass quality at the end of the day.
But feed conversion rate in the feeding barn was poorer with the foster hogs. The naturally reared hogs averaged 2.42 kilograms of feed for every kilogram of liveweight gain, while the others needed 120 grams more.
However, those who have seen the rescue deck concept applied in commercial units claim the piglets raised in this way often perform just as well as their conventionally suckled mates. They point out that the Futterkamp trial reported here weaned the rescue deck piglets onto dry feed almost a week earlier than the compared suckled piglets.
Three-canal teats make for healthier piglets
There are sows with a single milk canal per teat, many with two canals and some with even three functioning milk canals. Researchers at the Wroclaw Natural Science University in Poland claim that the three-canal variety can deliver a much higher content of antibodies to the young suckling piglets.
Antibody content in colostrum during the first two days of suckling is produced in the sow blood and the number of canals doesn't seem to influence supply in this case. Later, though, immunoglobulin antibodies are produced locally in the udder milk glands and production capacity appears to be connected positively with an increasing interior area of the teat canals. This means that the more canals, the greater the amount of immunoglobulin produced and potentially transferred into the suckling piglets.
With current commercial swine, there appears to be a huge variation in teat types. For instance, the Polish researchers looked at over 600 sows on three farms and calculated that the percentage of sows with only two-canal teats ran from nine in one herd to 51 in another.
Just to complicate matters more, many of the Landrace x Large White sows in the Polish investigation had teats with all three variations of teat canals on their udders! This was the case for an estimated 20 per cent of sows in one herd and for only one per cent in another. In between, there were sows with two-canal and three-canal teats and others with a mix of just one and two canals per teat.
As far as antibodies in the colostrum were concerned, the news for breeders is fairly discouraging. Not only do the amounts vary widely per sow, but the Polish work indicates that different pairs of teats on the same udder supply different concentrations of antibodies.
But at least one point is crystal clear from the Wroclaw University work. This is that a fair proportion of the Polish cross sows on test have teats with two and three milk canals and that these sows, later on in the suckling period, have the capability of producing more antibodies to help piglet health and survival.
Gilts and sows: sudden mixing is a no-no
The Danish Pig Research Centre is working on a strategy featuring a gentler introduction of gilts into the breeding herd where females are loose-housed. The system permits a four-week gradual acclimatization period for the young gilts before they enter the service facility.
What's working best for the Danes so far in this respect is the establishment of a separate pen for loose-housed gilts. Next door to this is the pen holding sows that have just had their litters weaned and are also waiting for service. The two pens are separated by a see-through gate.
The two groups are kept apart for two weeks, but otherwise have close contact through the bars of the gate. The gate is then opened and the gilts and sows are left to mingle, if they want to, for another two weeks.
Trials of this new system haven't been completed yet, but preliminary results indicate a significant reduction in hierarchy fighting and subsequent injuries, especially to the comparatively lightweight gilts.
The researchers point out that this is important because, in Danish herds where most sows are loose-housed, injuries to gilts are major causes of losses through early slaughter before the females have even started breeding. What often happens is that they get pushed around on slippery floors with resultant leg and hoof damage.
In commercial herds, the risk continues after successful servicing. Here, researchers believe the gradual acclimatization strategy could go a long way towards reducing casualties. Even more successful, but much more demanding in terms of management and space, is the establishment of stable groups for gilts only. Responsible for a lot of injuries is dynamic grouping where gilts and sows are continually mixed and new members constantly join the group.
The first step in a new campaign aimed at making life safer for young breeding swine on Danish farms is the publication by the Pig Research Centre of a "Gilt Manual" introducing strategies for increased care. Apart from the acclimatization tips, the value of daily evaluation of legs, feet and gait is emphasized in the booklet.
A simplified classification system entitled "Better Legs" is to be introduced in 2011. Linked with intensified veterinary involvement and supply of more hospital pens on commercial farms, this is to be another main weapon for Danish farmers fighting serious losses of young breeding animals each year. BP