Bolusing solves nutrient debate
Andrew Kinsella is to be congratulated on his sheep management article of August 17, which dealt with the now rapidly growing use of trace elements in the Irish livestock industry.
The need for correct intake of the key trace elements has been well recognised, technically, for many years now, but it has taken rapid rises in mineral costs and increasing pressure to sharpen up production to bring this area into focus for farmers. As in any developing field, products offered vary in the depth and value of their technical base. Commercial claims need to be seen in the light of practical results.
Having been involved in this subject from the 1960s, both in research and commerce in New Zealand, Australia, the US, Britain and Ireland, I know the impact which trace-element drenching has on deficient animals. But I am also well aware that to ensure safe and adequate intake of the four key elements -- selenium, copper, cobalt and iodine -- individual, slow-release administration is the way forward. This means bolusing.
The feed industry provides an interesting parallel. Low levels of these key factors, and of other less important micronutrients, are so common in bulk feeding stuffs -- particularly grain -- that it is standard practice for a micronutrient package to be included with virtually all manufactured feed. This makes sense, since it only takes one key element to be at a low level, for animal performance to be impaired. Bolusing allows the livestock producer on grass or forage systems to achieve a similar coverage of the four key elements.
Boluses, being slow release, require quite long periods of technical development to achieve the correct levels of supplementation -- ie, enough but not too much, thus avoiding the on and off effects of drenching.
The trace element field has been neglected by most of the large multinational companies who dominate much of the animal health scene. Smaller companies have filled the gap. In the case of boluses, products produced have been mostly technically sound because the time and cost of development has been a major investment for those involved.
Our own cattle boluses emerged from years of trial work conducted at Teagasc Grange and through on-farm trial work, with the kind co-operation of Dr Phil Rogers. The sheep boluses took a further three years of development with ADAS.
We have seen the use of boluses grow steadily since the 1980s and 1990s, and look forward to continuing co-operation with advisers and livestock farmers involved in this growing field.