To avoid the risk to beef calves from a prolonged calving SRUC experts now recommend feeding pregnant cows an enhanced ration 2-3 weeks before giving birth.
SAC Consulting’s Beef Specialist Gavin Hill says he has increasingly been asked about cows taking too long to calve and not getting on with the job of pushing the calf out. “In some cases prolonged calvings can result in more calf deaths. The simple change to feeding we are recommending should help to overcome the problem at very little cost. The goal is to ensure that cows can effectively mobilise calcium from their body to allow the birth process to proceed as naturally as possible.”
SAC Consulting now recommend that higher levels of magnesium are fed to cows 2 – 3 weeks pre calving – for example by supplementing with an extra 30g per day of a high magnesium mineral (15% magnesium) along with the normal mineral they use. This extra magnesium will help mobilise the cows’ own body reserves of calcium, improving muscle tone in the womb and preventing prolonged calvings and the detrimental impact that has on the calf.
To implement the advice producers need to know the expected calving date of their cows and group them accordingly. This will allow the additional magnesium to be targeted more accurately to only those animals in late pregnancy (for example by introducing them at a later date for groups of later calving cows). Predicted calving dates can only be determined by pregnancy diagnosis (unless AI has been used) and SAC Consulting strongly urges producers who have not already had their herd pregnancy diagnosed to do so as quickly as possible.
Pregnancy results so far suggest that the very cold late spring of 2013 has resulted in similar high numbers of barren cows as in the previous year. Identifying such animals early, to fatten them where necessary and cull them will help save tight supplies of winter feed and minimise the loss to the business.