Trace Elements in Health (animal studies)

Editor’s Note:  Although the two parts of this presentation apply specifically to trace element research in animals, they show the irreplaceable role of trace elements in building health, including strong immunity, robust organ function, healthy appearance, and optimal fertility and offspring.


R. Goodwin-Jones
Carmarthen, Wales, United Kingdom

Trace elements (TE) are probably the most important factor in the production of healthy productive ruminants, unless the pasture of the ruminant is balanced with TE then fertility, resistance to disease and the production of meat, milk, and wool are adversely affected. TE also affect soil life, and plants, and the whole ecosystem depends on these vital elements which are present in very small amounts.

A TE is defined as one which causes impairment of a vital function, or death, when its intake falls below a certain level and whose role cannot be undertaken by any other element. The biomass of the soil is immensely complex and is responsible for producing the nutrients for plants and the grazing animals. One square meter of soil to a depth of 6cm should contain approximately 75000 insects and small worms and 200 earthworms plus billions of fungi and single cell organisms. They should weigh about 1 ton per acre and on a permanent pasture may turn over around 15 ton of soil per year/acre. Nowadays this soil biomass is constantly degraded by modern farming methods.

The imperative TE are cobalt, copper, zinc, selenium and iodine. Less important possibly are manganese, boron, molybdenum and chromium. The major nutrients, potassium, phosphorous, sodium, calcium, magnesium, iron, sulphur and chlorine are rarely in short supply and thus are unlikely to influence the performance of a ruminant to any degree. Ruminants are able to select by taste and smell grasses that contain appropriate amounts of TE and their grazing patterns are dictated by TE content of grasses.

The trace element environment of the ruminant has clearly had a major effect on its genetic development. Different species and individuals within a species have different requirements of TE. Concentrations of TE in pastures depend on factors such as rainfall, altitude, aspect, base rock, temperature and geographical situation. Modern farming methods such as overuse of nitrogen fertilizers, lime, sulphur, and phosphorous plu a variety of herbicide and insecticide chemicals also reduce the TE availability.

When TE are low in pastures animals consume much more grass, which is much less nutritious, and they will suffer from more disease, and have fertility and production problems. Symptoms of TE deficiencies are many and obvious and these will be discussed in detail in part 2 of this series.


R. Goodwin-Jones
Carmarthen, Wales, United Kingdom

When the trace element (TE) balance in the pastures of a ruminant is correct the ruminant animal will generally remain immune to most of the common diseases and will reproduce efficiently and live a normal lifespan.

Symptoms of a TE problem are usually obvious to a trained observer and may be alleviated by the use of one or more of the imperative TE.  Ideally this would be carried out by the amendment of the soil medium but it may also be achieved by the use of oral supplements or injections. However denial of TE to soil and pasture renders the whole ecosystem much less efficient in the support of plant and animal life.

Symptoms of a TE problem are usually indicated by the colour, texture and abundance of hair or wool, and also by the condition of skin, horn and hoof.  Changes in the performance of tendons and ligaments and sometimes muscle become apparent with deformed fetlocks, high tail root, and a low slung head.  Common killer diseases such as E coli and pneumonia are symptomatic of a depressed immune system and which may be corrected by the use of TE rather than broad spectrum antibiotics.  Autopsy will often reveal necrotic areas of the liver, damaged intestinal surfaces and deteriorated heart muscle.

Reproduction is a fundamental part of Life and TE are the key to many of the more common problems.  Puberty is delayed, libido is reduced, females cycle irregularly and conception is poor or non existent.  Cystic ovaries are common and usually associated with a high tail root. Abortion near to full term, or miscarriage in early pregnancy may occur.  Sperm efficiency is reduced by a low count, malformation, and reduced motility.  The period of gestation is often variable resulting in premature or overdue birth.  Labour is often prolonged with poor uterine contractions and inadequate pelvic ligament relaxation.  Uterine prolapse is often a major problem for sheep and dilation of the cervix may be completely absent.  Malpresentation of the foetus for normal birth is very common and this will respond to TE correction.  The neonatal may die during birth, or very soon afterwards, the quantity of amniotic fluid may be much reduced resulting in a dry birth, or the amniotic membrane can be very thick causing suffocation of the neonatal.  The placenta are frequently retained, and the quality of the organ may be considerably below standard.

All of the above symptoms may usually be rectified if the TE balance is restored. Finally and interestingly, it is possible to adjust the ratio of male to female conceived for cattle and sheep by the use of TE.