Watch Condition of Autumn Calving Cows

Now is a good time to have a check on the condition of autumn calving cows.  Check your grazing regime and act if necessary, September is only 6 weeks away.  While it is ideal to manage cow condition throughout the year, this is often easier said than done.  Cows on good quality grass will put on condition rapidly.  Having over fat cows at calving time can cause issues with calving difficulty, fat cows also have a higher risk of metabolic issues around calving time.  If cows look to be fit then restrict their grazing, set stock the cows at grass of 4 cm.  If grass gets away from them then supply is greater than demand and cows are likely to gain condition, if it gets shorter than 4 cm then put in a ring feeder with straw.   Cows on restricted grazing can safely eat around 4 kg of straw.  If they are eating more than this, they are not eating enough grass and will need supplemented for protein and minerals.   If cows are calving later in the autumn and still have calves on them the calf plays an important role in stopping the cow getting too fat.  However, it is a fine balance between restricting the cow’s condition while maintaining the growth of the 9-month-old calf.  In this case the calf will require good grass and/or additional feeding to maintain good growth rates 

Producers should also pay attention to mineral supplementation especially magnesium coming into the backend. If grazing for autumn cows is restricted and straw is being fed, only half of the cows’ magnesium requirements will be met from the forage in their ration.  Ad-lib grass may suffice alone to supply a cow’s maintenance requirement for magnesium when she is under no pressure, but when stressors like weather, pre-calving requirements or lactation requirements come into play she needs much more.  This is particularly when her diet is being restricted. 

Karen Stewart, karen.stewart@sac.co.uk

For more information see FAS article Magnesium for Autumn Calving Herds and Magnesium Supplementation for Cows articles.