Ensuring good reproductive performance

Dry matter intake must be improving during this period to achieve good reproductive performance. Maintain grass quality and supply to give the cow the best chance of going and staying in-calf. But we must also ensure the cow’s requirements for micro-nutrients are met before and during breeding. 

It is well established that the micro-nutrient status of swards in the UK and Ireland are suboptimal; deficiencies of copper, selenium and iodine are widespread. As concentrate supplements generally contain added minerals, micro-nutrient deficiencies/imbalances are likely to become more prevalent unless farmers take appropriate steps to ensure that cows consuming a primarily grass diet receive supplemental micro-nutrients to compensate for deficiencies that exist in the grass on their farm. 

Clinical symptoms related to fertility are common between different micronutrients, but the real problem may exist where subclinical deficiencies exist leading to moderate reproductive performance. 

If we are to address these likely deficiencies, we must establish what the grass contains first. We can send grass samples to a lab for mineral analysis. The results will come back giving you the grass content of these essential micro nutrients in ppm or mg/kg dry matter. The dietary requirement of cows is usually given as a quantity (mg’s or g’s) of a particular micronutrient per kg of dry matter intake. You must then supplement the difference between what’s in your grass and what the cow requires on a daily basis.

Find more information on soil testing and grass analysis this spring from Yara Analytical Services