Weighty matters

Technological advances are making it easier to weigh livestock and use this information to influence herd management decisions. Glenneis Kriel spoke to a number of experts about the advantages of weighing livestock regularly.

- Glenneis Kriel

The dairy industry is probably one of the most advanced when it comes to the weighing of livestock, with most modern commercial dairies, even in South Africa, having an electronic scale to weigh cows after milking.

In these operations, each cow is fitted with a radio frequency identification (RFID) tag and weight measurements are taken using a walkover scale, usually installed in a walkway that guides the animals out of the dairy. This scale is positioned between gates, with the front gate closing once the cow has entered the weighing station and opening again when the animal pushes against it.

The weight is incorporated electronically into the milking programme in real time, which is pre-programmed to flag and sound an alert when the live weight differs from a 10-day average weight by more than a previously set standard, usually 10%. When this happens, a gate opens to let the cow into another walkway, where she will be inspected to determine the reason for the weight loss.

BENEFITS OF REGULAR WEIGHING

Weighing cows regularly like this has a number of benefits, according to Dr Carel Muller, a research associate at Stellenbosch University.

Firstly, the system enables farmers to monitor individual animals and compare them with others in the group. Animals showing a sudden deviation in weight, for example, may be ill. On physical examination, these animals may show signs of illness: for example, their eyes might be drooping, their ears hanging, or they may appear listless.

If nothing is wrong with the animal, the problem might be at the feeding station, which should be cleaned and checked for blockages.