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By Gerry
Brent, PCS Consultant With the pending removal of antibiotic growth promoters, still widely relied upon to prop up performance, producers and operators are beginning to get even more anxious at sluggish and uneven growth. "Well - it's Wasting Disease" commonly receives the blame for slow and erratic growth rates. However, this does not explain why some sites affected with PMWS/PDNS manage to achieve much more consistent throughputs from their finishing herds. So what might explain why some sites achieve acceptable and more even growth rates? Understandably, all costs nowadays come under scrutiny. Feed constitutes the major cost, particularly from weaning onwards and, since there is keen competition between suppliers, this is usually the first area to consider when economies are sought. This means that the cost per tonne of feed exerts a considerable influence upon the buying decision and how the product purchased is used. The prime example of how cost per tonne can affect performance is highlighted in starter feeds provided in the first weeks after weaning. The temptation to use less expensive diets containing lower quantities of good quality milk products is obvious and pig producers regularly succumb. All pigs benefit from a minimum quantity of a high-quality diet but the smaller pigs within a group are particularly responsive to this and their digestive system is likely to be compromised without it. Consequently, they are more likely to display looseness causing them to fall even further behind their bigger batch mates who are better able to deal with cheaper diets of lower nutritional specification. Such setbacks generated are commonly attributed to `Wasting Disease' but the truth is that PMWS will not usually trigger scours in the first two weeks after weaning - the cause is much more likely to be stress related or nutritional in origin and diet choice is a key factor. Any compromise created by feeding in this critical post-weaning phase will continue to manifest itself through the pig's life. This means that the symptoms are often grappled with rather than the cause -particularly where the pigs change sites or departments between the weaning and grower/finisher stages and it may be less easy to focus on previous treatments and management practices. Given these circumstances it is more difficult to empty pens or maintain target sale weights and to practice all-in/all-out hygiene. Not only that, mortality and the treatments needed are likely to be higher and carcass variability and eating quality compromised. The severity of PMWS/PDNS and variation in growth will not be completely overcome by the manner in which pigs are fed after weaning but it is true to say that:
Excellent
evidence is available from independent research work (click on graph
above), and producers are well advised to reflect on the importance
of knowing the value of getting post weaning performance right rather
than just the cost per tonne of feed made available.
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