NADIS is a network of 40 veterinary practices and six veterinary colleges monitoring diseases in cattle sheep and pigs in the UK.
NADIS data can highlight potential livestock disease and parasite incidence before they peak, providing a valuable early warning for the month ahead.
NADIS disease forecasts are written specifically for farmers,
to increase awareness of prevalent conditions and promote disease prevention and control,
in order to benefit animal health and welfare.
The forecasts are based on national trends and farmers are advised to discuss
their individual farm circumstances with their veterinary surgeon.
Over recent years there has been a trend within the pig industry in the UK to move to batch farrowing – farrowing larger groups of sows over extended intervals rather than the more traditional weekly group. Batches farrowing at intervals of 2, 3 and 5 weeks have all been applied with varying degrees of success. In this article the aim is to look at the purposes of batch farrowing, the mechanics of achieving it and some of the pitfalls.
There are 2 principle aims of farrowing more sows less frequently. The first to make better use of the buildings for health control purposes. Many farms are constructed in such a way that mixed ages of pigs occupy the same air and dunging spaces with the result that a cycle of disease is created from older to younger pigs. If a room or building can be occupied on an all in all out basis with pigs of the same age, cleaning can be more efficient and recycling of disease reduces. The technique has led to big improvements is disease control on many farms particularly with respect to the more difficult disease such as PRRS and PMWS.
The second purpose of batch farrowing is to make better use of labour. Stockmen can be concentrated into the 2 main jobs of serving and supervising farrowing if the 2 events occur in different weeks. With the current shortages of skilled stockpeople this is becoming an every increasing issue.
One of the greatest difficulties encountered is changing a herd from weekly to batch farrowing. The most important feature of the system is to achieve the aim i.e. farrow sows in a concentrated batch. A 270 sow herd targeted to farrow 12 sows/week should farrow 36 sows every 3 weeks in a batch system. Unfortunately for many producers in this situation they end up with 26 sows farrowing in the main week and 5 farrowings in the weeks either side. This achieves nothing in terms of labour use or disease control.
To change a herd over, it is necessary to manipulate the onset of oestrous advancing and delaying weaning of the groups either side of the target week. Alternatively, chemical manipulation can be used – Regumate (Janssen) can be administered to delay oestrous. If moving to 5 week batching the same approach can be taken or alternatively sows can be served normally and then aborted within the first month (using Prostaglandin’s) and reserved within the target week. Such programmes must be worked out in detail with the veterinary adviser well in advance.
Most batch-farrowing systems need to make use of AI – boar numbers would simply be prohibitive and so insemination technique should be addressed.
The major areas of concern revolve around what should be done:-
a) With gilts.
b) With returns to service.
c) With sows with delayed weaning – service interval.
For the system to work properly gilts should be treated with Regumate on a planned basis to ensure they are on heat at the requisite time. Returns should only be reserved if they fit into the normal service programme. Otherwise they require culling. The same applies to delayed heat sows.
The result of such serving programmes tends to be higher culling rates, less selective culling and reduced farrowing index. However, if applied rigorously the benefits will out weigh these disadvantages.
In considering a move to batch farrowing building provision requires consideration. In the above example of the 270 sow herd farrowing weekly 60 crates are likely to be adequate. Farrowing in 3 weekly batches will require an extra 12 places (5 weekly batches only require 60 places). The costs of additional buildings (including service area) will need to be carefully worked out.
In conclusion, batch farrowing can make a highly significant contribution to health control and labour use. However, it is not an exercise to be entered into lightly. If not done correctly it achieves little but at extra cost. Planning both strategically and on an ongoing basis are essential to make the programme work and cutting corners – e.g. over gilt service programmes – will not pay dividends.
Mark White BVSc DPM MRCVS
Copyright NADIS 2005 www.nadis.org.uk
While every effort is made to ensure that the content of this forecast is accurate at the time of publication, NADIS cannot accept responsibility for errors or omissions.
All information is general and will need to be adapted in the light of individual farm circumstances in consultation with your veterinary surgeon