Beef and sheep notes March 2010

As the main spring calving season approaches, walk through cows and feel if the bones have dropped in those getting slack around the vulva. Just glancing across the feed barrier can lead to some nasty surprises when calving commences. Also handle cows over the loin and around the tail head to assess cow condition. Separate out any cows showing signs of calving, being bullied or having difficulty in rising due to feet problems or stiffness.

Ideally spring calving cows should calve down in a condition of 2-2.5. A lower condition score than this will lead to weaker cows (downer cows) and much slower re-breeding, resulting in an increase in calving interval. Thin cows may also produce poorer quality beastings and calves that are at greater risk of disease.

Cows due to calve in the next six weeks which have not reached this condition will now struggle to achieve it. Meal should not be introduced to these cows to alter condition at this stage as it may contribute to increased calf size, difficult calvings and mastitis. It will be much more beneficial to introduce meal to these cows 10 days before calving and try to maintain condition thereafter. For cows in excess condition try to manage this by targeting poorer quality forage to this group or introduce some straw if available.  

Aim to achieve a good calving interval (time in days from cow calves until she calves again) of 365 days and cull cows that are not calving regularly every year.

Comparison of the output from two cows with different calving interval.

Assumptions:

Both cows initially calved on 1 January in year 0.

Calf weighs 45kg at birth, gains 1.0 kg per day on the cow and is sold on 1 October

A calving interval of 365 days (each day over costs £1.50 per cow) can be difficult to obtain in suckler herds due to poor body condition of the cows at calving and slowness to come back into season and settle in calf.

For 400kg cattle which are to be kept for grazing and  are being fed ad-lib silage (ME 10.8MJ/kg) plus meal a sensible approach would be to gradually reduce the amount of meal by about 1 kg per head per week until they are just on ad-silage for the last month. If silage is of poor quality (below ME 10) maintain meal feeding at 1kg per head per day right through to turnout. Benefits include saving on meal costs and better compensatory growth at grass.

Feeding a good concentrate pre lambing will ensure adequate colostrum supplies and continuing to feed post lambing will boost milk production. The growth rate of a lamb to six weeks old is largely dependant on the mothers milking ability.

Protein is one of the main factors affecting milk production. Protein level in the ration should be 16-18% on a fresh weight basis. The best quality proteins are rumen bypass proteins or protected proteins. These are generally based on soyabean meal but have been modified slightly to improve the protein quality. Soyabean should form the main part of the protein source. Rapeseed can be used but at lower levels as its quality is not as good as soyabean. Wheat distillers is generally not recommended for sheep rations as it is high in copper which can be toxic.

Energy in the ration can be provided in the form of starch via wheat, barley and maize. Avoid finely ground cereals or over processing as this could increase the risk of acidosis. Sugar beet pulp is also a useful source of energy and provides this in the form of sugars as opposed to starch. Protected fats, although expensive, can dramatically increase the level of energy without affecting fibre digestion.

With good quality precision chopped silage where intakes are high, meal levels rising from 0.4kg/day a month out to 0.6kg per day at lambing are satisfactory.