I've been working in Central Europe recently and while everyone seems happily fitted up with competition or plate feeders for growers, I notice that the operation of them leaves a lot to be desired.
Surprising this, as a great deal of information is available on how much food should be available on the plate/ dish/ bowl – and troughs – where these are used. I saw far too much on offer to the pigs.
I quote the reliable Irish work (Walker and Morrow, 1994) which showed that a correct throat setting compared to an overgenerous one worsened FCR (25-90 kg) by 0.11. This does not sound much but I calculate from their results that this is 31 kg less saleable meat (MTF) secured for every tonne fed.
Assuming about 10 tonnes of food passes through each hopper per year, then at the pretty low dressed carcass prices in the EU just now and assuming a hopper costs £150 (€175), then the hopper is paid for in six months.
So don't stint on hoppers, especially as more and more people are moving towards the 'Big Pen' idea.
Following on from this, another thing I saw was that often there were far too many pigs feeding from one hopper. Harold Gonyou in Canada and others have done work on this and came to the conclusion that 80% feeder occupancy at any one time during daylight hours probably supports maximum growth rate. Thus stockpersons should be ensuring 20% of feeder space is free at any one time.
Eating time is important so as to avoid over-occupancy at the trough. If a normal eating period for all pigs in the pen during the day was 18 hours, and as the researchers suggest, the average eating time for one pig cumulatively in one pen was 60 minutes across the day, then the feeder should support 14 pigs at most – not the 20-25 I so frequently see where food conversion will suffer. Longer cumulative eating times of 70 and 80 minutes for each pig would reduce this to 11 and 9.
But most stockpeople are far too busy than to try and measure eating times (perhaps they could keep in mind that 20% un-occupancy time as a rough check) so what this work suggests is never to have too little feeder space. Especially as the Irish work suggests that even at today's prices feeders used with correct throat settings are not 'expensive' at all.
This is a big and well-researched subject, including what the throat setting allowances should be, and obviously needs better circulation, maybe considerably condensed for my monthly column in Pig Progress – or even for a longer survey if the editor will allow me the space. It deserves it, I guess.