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What the textbooks don't tell you about…Computerised Wet Feeding: Past, present and future

I confess that I have been a lifelong convert to the wet (pipeline) feeding of pigs. For myself it all started on the Taymix farm in Dorset, England when with some 12,000 growing pigs to feed, the pump of our wet feeding system broke down and the replacement part took three days to arrive. All hands, including myself as technical director were mustered to carry bags of feed to each of the 800 pens. Twice a day. I finished at two in the morning and had to be back at it again at 6 am. For three days! That brought home to me what a labour-saving device it was! By John Gadd

By John Gadd

The past
And what a learning curve it was, too! Not only to have a spare or two for every working part you could think of – but, just as important, to have a back-up plan ready should more than a 12 hour breakdown occur.

If the technical advances of the past 20 years are continued at the same pace, the future possibilities seem limitless.
Over the years we had to face and overcome, largely by trial and error – flocculation (separation of particle sizes in the pipeline, causing blockage), cleanliness (at trough, mixer and delivery lines), overeating (the pigs just loved the liquid ‘soup’ and got fat), how to balance the host of cheap by-products available (difficult, as
everything was so variable in analysis), correct pen and trough shape (a pig just loved to fit snugly inside the generous troughs we provided for 50 pigs to all eat at once – providing a very effective dam causing a tidal wave of valuable food to exit all down the slats, just to name some of them. Virtually, we redesigned the trough to prevent ‘lying-in’.
And there was the difficulty of convincing the producer that wet feeding was a (atmospherically) wet process and that the ventilation must be uprated professionally to take account of this and not to blame the system or the change to wet food for fits of coughing by the pigs.
The present
While Computerised Wet Feeding (CWF – previously known as pipeline pig-feeding) is commonplace now, considering the benefits are well-established and impressive and the limitations not insuperable (see box) you may well ask why the concept is not established on 90% of world farms rather than the 10% to 60% in the countries I visit.
Take the USA, for example, which to my mind shows an uncharacteristic refusal by these go-ahead people – farmers and academics – to have anything to do with CWF. American farmers (but not so much Canadians in Ontario) still remain firmly wedded to their dry feed hoppers despite the appalling wastage which is so evident (12%, and even 6% on the best units I have been privileged to be shown).
When I ask them why, there have been various replies as to why not to move over to CWF. But knowing the Americans well after 30 years of visiting their farms, attending their conferences, one day the penny will drop and then an avalanche of enthusiasm will descend, just as it is beginning to develop now over their keeping sows in groups rather than the publicly-abhorred stalls. I only hope they will benefit from our years of experience of both concepts.
The problem of cost – still apparent today
One of the barriers to converting to CWF has always been the cost. As a lump sum it is expensive, sure. It was, but less so, in the past, is now and is likely to remain a major barrier in the future. Compared to a modern dry feed system, a modern CWF set-up can be between five to ten times more costly. Of course this puts people off, although a good deal of this can be in the buildings advised, including ground plan and cover over. In Table 1, for example, the cost of just the minimum CWF equipment (€40,000 as quoted by two authoritative bodies who have gone through things properly) is nearly two-thirds less than that cited in Table 1, which included new housing cost.
But I show Table 1 as an economic worst-case scenario, as even here the payback is a proven 2.5 years. All the CWF clients who have shown me their figures have not exceeded three years and several cite 15 months. After that cost of production savings are in the region of €4-€5/pig – and more if co-products are well-bought.
Does CWF depend on the use of co-products?
Not at all, although this is a common question from the newcomer. Water is a perfectly satisfactory means of moving bulky feed, saving onerous and unpopular labour and reducing dust. Liquid or liquefiable by-products are simple to add, are a lot cheaper per unit of energy or lysine than conventional dry raw materials if balanced carefully from declared nutrient specifications provided hopefully by the vendor.
I find this is a high goal to reach in practice and paying on dry matter (DM) content and checking the DM content on delivery (a very simple and rapid test done in the office) is important until suppliers improve the consistency of their products, which is happening. Really bad DM under deliveries can then be referred for a price reduction on that batch and/or passed to a nutritionist for reformulation.
Is such ‘diet-tweaking’ worthwhile? It seems so, as where this has been done food conversion has improved by 3% and MTF (saleable Meat per Tonne of Feed) rose by 9 kg. That doesn’t sound much but it is equivalent to an immediate 8% fall in the cost of a finisher feed, definitely not to be sniffed at. Again in practice, if the supplier’s product varies that much then it is useful for the nutritionist to supply a range of standard reformulations to save inputting a new ration formulation every time – the CWF computer can do this in a couple of minutes and as often as you like. Just press the buttons or let the nutritionist do it from a distance.
The future
If the technical advances of the past 20 years are continued at the same pace, the future possibilities seem limitless – if only from what we know is possible today but which is not being put into practice due to a variety of practical hurdles which have not only put farmers and the feed companies off, but has also stunted investigatory research whose scientists feel there might be no market, at least for a while, so research funding is deflected elsewhere.
In addition, there are a number of future possibilities not yet explored and surely others yet to be discovered – who knows what lies around the corner. If some of these suggestions seem fanciful – think back to the present advances in pig nutrition, management and disease control which were unimaginable 50 years ago when I began my career in pigs.
Some ideas which CWF could unlock and go on to exploit
* The holy grail of feeding grass, brassicas, discarded vegetable haulms and even hedge-clippings to pigs.
* In the tropics, banana leaves and other exotic plants likewise.
* Synthetic amino acids not needing to be dried (and thus are 28% cheaper, I’m told) if available in liquid form added at the farm.
* Likewise existing protein sources with far less pre-processing needed and delivered by tanker. Vitamins too in liquid drum concentrations.
* If the challenge feeding concept eventually surfaces, potentially of huge significance in matching diet to immune challenge, then CWF is ready and waiting to accommodate the on-going dietary changes needed as the immune threshold changes.
* As it is for the blend feeding concept where the feed manufacturer can mix 300 different diets from just two bins, maybe a small third one for additives. This brings the farm-specific diet into play (another holy grail) which removes the need for the feed mill having to stock an expensive product range and warehousing costs.
* Phase feeding seems to have stumbled recently as not all the research is positive and the reasons need more research. Especially into multiphase feeding where a protein accretion curve is followed daily and frequent changes made to the nutrient specification which can be handled effortlessly by computerised wet feeding.
* We already are seeing ESF-type technology applied to automatic weighing (tomography) and sorting, heat detection and adjusting diets to environmental variation. CWF is even better-placed in the first and the last as it is predominantly involved in the growing/finishing pig where these concepts have the greatest impact on production cost.
* The possibility of (advance) disease detection is an exciting new area – CWF could take this on perfectly well as it is present in every pen every day.
* Lastly, menu feeding for nursery pigs and choice feeding for all pigs are ideas which have blossomed and seem to have faded, mainly due to logistical difficulties which may have discouraged the researchers. If this was so, then CWF could address these snags. Time for another look?
So in my experience of growing up with CWF since its early days in the 1960’s has been…
The past has been all hard graft – making mistakes and learning, developing and encouraging people to do things correctly.
The present is all about the cost-effectiveness of what seems at first glance to be something refined and workable but which seems difficult to afford – more persuading!
The future for CWF is potentially quite extraordinary. Coming aboard? 
Advantages of Computerised Wet Feeding
* Pigs do better
A survey of the literature I did several years ago showed:
Effects of                                Growth                        Carcass
wet feeding                             rate                 FCR    quality
Improvement                            37                    32        8
Deterioration                            4                      5          2
No significant difference            12                    16        16
No information                         -                       -           27
To 2009: Since then, 28 opinions of farmers who have made the change report a similar trend, with grading – subsequently remedied by a nutritionist – the only initial problem. “Growth rate and MTF (Meat sold per Tonne of Feed) are noticeably better.”
* Less food wasted
Three farms, 5,000 finished pigs produced year, feed amounts in tonnes/year.
                        With                Without           Savings on
                        wet feed          wet feed          transfer to wet feed
Farm 1             770                  838                  68 tonnes
Farm 2             803                  900                  97 tonnes
Farm 3             984                  942                  42 tonnes
* Pigs eat more, convert better
Appetite can be a limiting factor these days. This is a problem in the modern hyperprolific sow and gilt, and in all pigs in hot conditions. For finishing pigs, FCR (30-105 kg) is often 0.1-0.15 better. For sows up to 1 kg/day in lactation more with piglet mortality to weaning down 1.7%, farrowing index up 6%, sows served by five days or less 23% higher, weaner weight/sow/year +17% (from 126 to 148 kg).
* Sow farrowing crate occupancy is better
Weaner weight per crate +11%.
* Dust is markedly lower
Meal 14-79mg/m3. Pellets 5-23 mg/m3. CWF 0.5-14 mg/m3.
* Healthier stockpeople
Fewer coughs, eye, nose and throat irritation, less days off work.
* Happier stockpeople
One laborious task removed: Manhours/week spent preparing food and feeding 5,000 pigs: dry 20-30; wet 5-6. Staff turnover/year: 42% dry, after wet feeding 10%. Easier to recruit youngsters due to promise of computer use.
* Quick and accurate medication
Literally within seconds even at very high dilution rates, affording 50% reduction in medication mixing costs.
* Less slurry from sows
Tanker loads from the sow herd: with dry pellets 3-5. In case of CWF 2-4.
* Less stress
Now a major ‘hidden’ problem in all pigs. Time spent dozing/sleeping (pigs 20-50 kg): with dry pellets 45%; when wet-fed 53%. After a wet feed 70% of grouped sows settled down to rest within 45 minutes compared to 80 minutes on dry pellets. Several farms report a permanent disappearance of tailbiting when changed from dry feed to a thick (3:1) mix.
* Less mycotoxin damage
The other ‘hidden’ problem in all pigs. Because the mixing tank and pipelines can be or should be regularly sanitised and the pigs ‘polish’ a trough when feeding is finished, residual mycotoxin build-up is lowered or even eliminated. However, ad-lib troughs and sow troughs need careful attention and it is advisable to add a mycostat or mycoabsorbent to these wet feed mixes as a precaution.
* Many future possibilities
CWF is still 20 years ahead of its time, see also the main text.
Drawbacks to Computerised Wet Feeding
* Installation cost
Considerable, largely depending on existing suitability of piggery conversion. Many reports show that payback has been within 30 months – some 36 months but no more. After that, the benefits have averaged around €4 to €5 per finished pig.
* Quality, skilled and well-trained staff: essential
This is particularly true when starting pigs as young at six weeks (12 kg) where strict cleanliness is essential and fresh, little and often feeding practiced.
* Monitoring
Care has to be taken to monitor bushel weight of ingredients and to keep a check on co-product nutrient density and shelf life.
* Malfermentation
This can occur with weaners and sows but is not a serious problem with growers/ finishers. Care and experience will avoid most of it.
* Whey bloat
Older pigs can bloat, especially on whey. Anti-bloat whey balancers can help but in the author’s experience 1% more finishing pigs may be lost to this.
* Ventilation
This needs to be professionally checked at installation Wet feeding is a wet process!
* Frost
Rarely a problem if the installation is designed to accommodate frost and wind chill. Learn from the Canadians, Swedes and Finns.
* Blockage
This can happen, but very rarely in a set-up installed by a professional who will design-out danger spots and install easy remedial action should a blockage occur.
* Overfat pigs
This can occur after changing from dry feed. Initially this is quite common especially on adlib short troughs and at first dismays the novice, but is rectified by referring matters to a pig nutritionist who will readjust nutrient density to match appetite.
 Source: Pig Progress Volume 25 nr 9


Pig Progress, volume 25, no.9 2009

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