What is Thiomolybdate Toxicity (TMT), and how can I treat and prevent it?

TMT is often misdiagnosed as copper deficiency. This is because it results in the same symptoms as copper deficiency (such as gingering coat in cows, poor fleece quality in sheep, balding eyes and poor fertility). However, TMT is not caused by a lack of dietary copper and animals with TMT will show normal blood copper levels. So what’s going on?

Understanding Dietary Thiomolybdate Toxicity (TMT)

Molybdenum and sulphur from the animal’s diet combine in the rumen to form thiomolybdate. Thiomolybdate will bind with copper present in the rumen. When there is insufficient copper in the rumen, thiomolybdate will move into the bloodstream in search of further copper. It is here, in the bloodstream, that TMT occurs. Thiomolybdate combines with copper co-dependent enzymes in the blood, which are vital for fertility and thriving, and renders them inactive.

Does Iron Play A Role?

Yes, iron and sulphur in the rumen also combine with copper and create a stable compound which passes out of the animal, thus reducing the amount of copper in the rumen and increasing the likelihood of TMT. Thiomolybdate Toxicity is highly damaging to the animal and can cause:

  • infertility
  • decreased conception rate
  • anoestrus
  • delayed onset of puberty
  • decreased energy utilisation
  • gingering coat, reduced fleece quality, bald spectacles eyes.

In-field Results

Wayne Underhill, of Harley Thorn Farm in Beech, Stoke-on-Trent has 1200 New Zealand Romneys on HLS (High Level Stewardship) Land, which is deficient in copper and many other trace elements. Prior to farming in Beech, Wayne spent 10 years as a shearer in New Zealand. Five years ago Wayne spoke to Kate Phillips from ADAS about the best approach to take addressing the trace element deficiencies that he felt were affecting the health and fertility of his flock. Kate recommended the Cosecure sheep boluses, stating that she found them superior to other boluses. They deliver the same levels of copper, cobalt and selenium every single day for up 8 months, at levels compatible with the animal’s needs, so the farmer knows exactly what his sheep are receiving. Prior to using the boluses, Wayne also got advice from expert in ruminant trace element nutrition, Mr Peter Bone, as well as his local Vet, Mr Eddie Friend, who both recommended Cosecure boluses as the best means of addressing his flock’s trace element deficiencies. Wayne commented,

“I have been using the Cosecure sheep boluses for 5 years now on my flock of 1200 New Zealand Romneys and I am really impressed with the results. These boluses really made a difference and were a great return on investment for me. They have had a great impact on fertility, fleece condition and the general health of the animals. In fact, my lambing percentage increased from 160% to 190%, which is phenomenal. The condition of the animals’ wool also improved immeasurably and the flocks’ health noticeably improved. Their condition is held all winter and they are more milky.”

Wayne added,

“there are so many boluses and supplements to choose from that it’s hard to see the wood for the trees sometimes, but I was reassured by the fact that three experts recommended Cosecure to me. They explained that Cosecure boluses are unique in the way they work and that they contain pure, ionic copper and cobalt, which other boluses don’t. Pete mentioned that they’ve been proven in trials to improve fertility, health and productivity, which was also reassuring. Since using them, I have certainly reaped these benefits, which is great news for my animals and for my profit line. I’d be happy to recommend them to any farmer who needs to address trace element deficiencies and wants to see real improvements.”

At Agricentre we stock a full range of Bimeda sheep (and cattle) boluses including Cosecure, Coseicure and Zincosel, so speak to one of our team to find out more. Why copper is not as simple as we might initially think and is challenging our understanding of supplementation.