Dairy Infertility
Independent research by Cumbria Vet
David Black compared three methods of supplementing copper; injections, a matrix bolus which claims to supplement a wide range of trace elements and Cosecure (glass boluses). Cosecure treated cattle became pregnant at a rate 1.8 times higher than copper injections and 1.4 times higher than the matrix trace element boluses. David Black goes on to conclude that this effect is best explained with reference to molybdenum.
Our explanation of these results
Molybdenum combines with sulphur in the rumen producing thiomolybdate which actively combines with copper. When it does so it makes the copper unavailable to the animal. This is OK if the copper is not being used for vital functions, but in fact most of the copper found in the blood of ruminants is being used in enzymes. So when thiomolybdate combines with this copper it deactivates the enzymes. This can be seen as a toxic effect and the best place to remove toxins is at the site of production.
Whilst it is clear that molybdenum induced infertility can be reversed by supplementing copper the exact mechanism causing the infertility is less clear. Molybdenum may be producing toxic effects other than simply attacking copper bearing enzymes. Whatever the mechanism regular supplementation of copper to the rumen reverses the problem.
Only Cosecure provides a regular supply of copper to the rumen over a period of up to four and a half months in Dairy Cattle covering them in the vital period from calving to early embryo development. This explains why Cosecure is so much more effective than other copper supplements.
This explanation backed up by a wider study
In a wider study of copper responsive infertility, using data derived from 11 veterinary practices who sent in three or more representative sets of samples, clinical observations backed up the laboratory analysis. This study also adds weight to the argument that total plasma copper levels are of little diagnostic value. Only 33 samples out of 713 were in the deficient range i.e. less than 9.4uM, but when caeruloplasmin activity/plasma copper ratios were measured 409 had probable or definite thiomolybdate problems requiring copper supplementation and of these 201 had distinct thiomolybdate problems.
11 of the fifteen practices responded to a questionnaire and 9 of these said that they had seen positive results by supplementing copper in those cases in which this had been recommended. 10 of the 11 stated that copper supplementation reduced the incidence of poor or no bulling activity and later embryo loss. In additional comments one practice said that they had used Cosecure to treat a lack of oestrus with ?dramatic and immediate responses?. This paper shows that the use of caeruloplasmin activity to plasma copper ratios is a reliable diagnostic tool in identifying cattle that will respond to copper supplementation. This is now confirmed by field observations by practising veterinary surgeons.
