WITH trace elements playing a critical role in the fertility, productivity and welfare of dairy and beef cattle, it is vital that farmers review their trace element supplementation, to ensure nutritional requirements are considered and that appropriate testing is taking place, writes Dr Renée Lodder, technical veterinarian, Bimeda Animal Health.

Many farmers are aware of the potential for deficiencies in trace elements such as copper, cobalt, selenium and iodine and are aware of many of the clinical signs of these, which include: coat discolouration, hair loss around the eyes, diarrhoea, white muscle disease, retained placentas, weak new born calves, goitre, lethargy and poor growth.

However, these trace element clinical signs are the true tip of the iceberg and many times deficiencies are subclinical and are not easily observed. The losses from trace element deficiencies occurs in the forms of: poor growth rates, lower reproductive results and lower production compared to their genetic potential.

In addition, a condition called thiomolybdate toxicity can also look like copper deficiency. The absorption of copper can be significantly reduced by the ingestion of molybdenum and sulphur in the diet. Molybdenum and sulphur combine in the rumen to form thiomolybdates. These react with copper to form copper thiomolybdates. This means that copper is lost from the animal via excretion in faeces.

When detecting trace element deficiencies, ideally, forage analysis, blood tests and liver biopsies (both live or from the abattoir) would be beneficial to get an indication of intakes and levels in the animals. Forage analysis is important in getting a picture of what trace elements are being supplemented to the animals and whether thiomolybdate toxicity is an issue on the farm.

The Cosecure and CoseIcure cattle boluses

Trace elements such as copper, selenium, cobalt and iodine are vital for cow fertility, and where a deficiency has been diagnosed, it is important to address it via a proven method of supplementation. The relevant trace elements should be supplied to the animal at required levels and at consistent rates, particularly during key periods during the production cycle.

However, it is not just the trace elements themselves which are critical, but also the way in which they are supplied.

It is important to ensure that all animals receive an amount of trace elements that is compatible with their daily requirements. Too much of a trace element can prove toxic, too little and the deficiency will not be addressed.

Peaks and troughs in the levels of trace elements supplemented can have a negative impact on fertility and health, so it is critical to select a form of supplementation that is proven to deliver the same levels of trace elements each day.

One such method is the Bimeda Cosecure Cattle bolus, which supplies ionic copper, ionic cobalt and selenium at a controlled and constant rate, for up to six months.

This is also the only medicinal multiple trace element bolus in Ireland or the UK that has demonstrated increased reproduction outcomes in an independent trial. The research involved a dairy herd at the University of Leeds and the cattle in the trial had all previously suffered from low conception rates and anoestrus. Some had shown visible signs associated with copper deficiency and thiomolybdate toxicity, such as ‘spectacles eyes’ and poor coat colour.

Cattle to which the boluses were administered benefited from increased fertility compared to the control group and had significantly fewer inseminations than non-bolused animals and had a significantly shorter calving interval than non-bolused animals.

Many cattle also suffer from iodine deficiency and Bimeda also offers an iodine-containing bolus called CoseIcure. Like the Cosecure bolus, CoseIcure lasts for up to six months and delivers ionic copper, ionic cobalt and selenium, as well as iodine.

Role of Molybdenum and Sulphur

High levels of ingested molybdenum and sulphur are an additional issue, which can combine in the rumen to form a compound called thiomolybdate. Thiomolybdate can bind with the copper co-dependant enzymes in the bloodstream, which play a role in fertility, and render them inactive. This phenomenon is known as Thiomolybdate Toxicity (TMT). TMT looks very similar to copper deficiency in cattle and is sometimes referred to as copper lock, or secondary copper deficiency.

The Cosecure and CoseIcure boluses contain a unique form of copper known as ionic copper, which is known to be highly effective at combating the negative impacts of molybdenum and thiomolybdate, and preventing thiomolybdate toxicity from occurring. The ionic copper in the boluses is available at the same pH as the rumen.

Here it binds with thiomolybdate and prevents it from moving into the bloodstream and causing Thiomolybdate Toxicity. This means the boluses are a popular choice on high-molybdenum farms, following on from appropriate diagnostics.

The Cosecure and CoseIcure boluses also have a unique delivery system, being made of a unique soluble glass which dissolves at a controlled and constant rate. This means that the boluses deliver consistent rates of trace elements each day, at levels which are consistent with the daily requirements of the animal. This is an important feature of the boluses, as peaks and troughs in trace elements can adversely affect fertility

It is important to note that trace elements in any form should only ever be given on the basis of a diagnosed deficiency and on the recommendation of a veterinarian, nutritionist or animal health adviser.

For more information, call Bimeda on 01248 725400.