Tom Green of Craven Farm Vets looks at ways of improving suckler cow fertility.

With most suckler cows out at grass, it is an important time to ensure they are in optimum health to get back in calf again.

Trace element deficiencies are an important cause of infertility, with levels of trace elements varying greatly across the North of England. This is due to location, geography, soil health, and issues with poor scanning. Also, cows coming bulling repeatedly or not coming bulling at all warrant further investigations from your vet.

The main trace element deficiencies encountered are:

Copper

In adult cows, copper deficiency is associated with decreased fertility. Deficiency results in increased time from calving to normal bulling activity, decreasing the chance of a cow getting in calf.

Although copper deficiency can be due to low dietary intakes it can also be due to high intakes of molybdenum which binds to copper in the rumen, reducing the animal's ability to absorb it.

Selenium

Selenium and vitamin E play an important role in protecting cells against damage and muscle development. Deficiencies can result in stillbirths or calves that are born weak. In cows, deficiencies can cause an increase in post-calving problems such as metritis and cystic ovaries which can both result in a delay to the cow coming bulling.

In bulls, selenium deficiency results in reduced fertility due to negative impacts on sperm production.

Iodine

Iodine deficiency during pregnancy can result in a higher risk of calf death and abortion at any stage of pregnancy. It may also cause stillborn or weak calves, that are unwilling to suck and higher perinatal mortality.

In lactating cows, it can become associated with poorer growth rates in their calves, poor milk production and retained placenta, as well as cows taking longer to come bulling after calving and bulling at irregular intervals.

Cobalt

Cobalt deficiency impairs breeding performance in cattle, which may lead to a reduced chance of getting in calf. Cobalt deficient animals take longer to recover after calving and are more likely to come bulling at irregular intervals.

Testing for trace element deficiencies can be complex with some tests being more accurate than others. A range of tests are available from blood sampling to liver biopsies. The timing of testing is also a very important factor, all of which should be discussed with your vet to give you the best chance of an accurate diagnosis.

There are several ways to ensure cows get adequate supplementation of minerals at pasture, but be cautious of:

  • Lick blocks/ buckets: these are the least preferred method of supplementation. The intakes are not likely to be consistent across the herd as some cows are likely to take more than others and some may not use it at all. Other issues with access to wildlife and disease transmission should also be taken into consideration.
  • Boluses: there are several different types of boluses on the market but beware not all provide the supplementation you may needthey claim, speak to your vet about your specific needs too.
  • Drenches: these are very good at raising levels in the bloodstream, but they only last a very short period, and again different brands contain different levels of the minerals required.

Discussion with your vet in combination with test results is important to work out the best way to supplement your herd.