The role trace minerals have in pig nutrition on the overall well-being and peformance of the pig can be overlooked, but just because the addition in the diet is small it doesn't mean the impact is, Dr Casey Bradley explains.
As swine nutritionists, it’s all too easy to focus most of our ration formulating efforts on energy and protein (amino acids). Fine tuning ingredients for the perfect balance to optimise pig performance sometimes seems as much an art as it is a science.
The role of energy and protein in pig nutrition
Prioritising energy and protein makes a lot of sense, as getting either of these wrong can rapidly undermine growth, fertility and efficiency, reducing income and increasing costs. Yet is the end result a tendency to overlook the importance of the small things in the diet? We check to make sure minerals are within recommended guidelines, but should we focus more on the micro to ensure we optimise animal performance?
Trace mineral content may be small but the impact is great
Just because the requirements for a particular trace mineral are in the parts per million (ppm) or parts per billion (ppb) doesn’t mean it has any less importance or impact than one required in grammes per day. The role played by minerals may be a supporting one, but it’s critical to efficiency and performance.
My PhD dissertation investigated the effect of organic trace minerals on sow longevity, so it’s a topic that’s close to my heart. The particular challenge we face today is that the past decade has seen substantial change within key aspects of pig nutrition, yet the need to update and adapt mineral nutrition to match is often given little priority.
Phystases in swine diets
A good example of a recent nutritional development is the increasingly widespread application of phytase in swine diets, particularly where superdosing is used to virtually eliminate that great mineral binder, phytate.
The standard use of phytase to release phosphorus (P) results in the production of lower order esters of phytate (IP5, IP4, IP3 and IP2) that can be just as detrimental to mineral availability as phytate (IP6). The negative effects of these lower IP esters can be negated by the use of superdosing phytase (> 1,500 FTU/kg of an enhanced E. coli) that degrades phytate below IP3 with the release of free inositol.
Given that 1 study measured the iron (Fe) binding potential of IP5, IP4 and IP3 to be as high as 70%, 34% and 26% respectively, compared to 69% for IP6, the impact on Fe nutrition can be substantial.
For example, compared to the typical negligible effect of raising dietary Fe levels in starter diets, increasing supplemental Fe content from 200 ppm to 350 ppm in the presence of superdosing increased post-weaning average daily gain (ADG) by 10% and feed conversion efficiency (FCE) by 7%. With phytate out of the way, the extra Fe was actually available to be absorbed and utilised by the pig!
In contrast, reduced phytate binding of zinc (Zn) following superdosing has been shown to allow Zn inclusion in starter diets to be reduced by 500-1,000 ppm, with Zn still at pharmacological levels, without losing performance benefits.
Such examples are just the tip of the mineral iceberg, though they do highlight the potential for additional gains if minerals are given the attention they deserve.
As the great US basketball coach John Wooden once said: “It’s the little details that are vital. Little things make big things happen.”