Calves rely on the passive transfer of antibodies from colostrum to establish immunity. Failure of this process can lead to calf disease and death, affect growth rates, milk production and reproductive performance in the first lactation.
Prevention of failure of passive transfer is summarised by the three Q's of colostrum management:
Timing of the first colostrum feed is crucial. Over the first 24 hours of life, the ability of the gut to absorb antibodies decreases. The first feed of colostrum should be in the first six to 12 hours of life.
Minimum of 10-15% of calf live weight. A 40kg calf would need 4L. As the stomach capacity is approximately 2L, this would need to be split into two feeds.
Good quality colostrum has high antibody levels and low bacterial contamination. Colostrum antibody levels can be measured on farm using a brix refractometer.
The first two Q's are easily controlled with good calf management. The third Q is where many farms struggle. A recent New Zealand study found that only 9.7% of farms surveyed had adequate colostrum antibody levels, and only 8.9% achieved the threshold for contamination. When both criteria were applied, only 1.8% of samples were of adequate quality!
Colostral antibody levels depend on several factors. It is important that colostrum fed to newborn calves is FIRST MILKING colostrum. In addition, the calving to first milking interval and milking to feeding interval should be minimised, as antibody levels decline over time in both the cow and the bucket! Pre-calving herd vaccination with vaccines such as Rotavec® Corona or Scourguard® 4K will boost specific antibody levels in the colostrum.
Bacterial contamination of colostrum prevents absorption of antibodies in the gut. The importance of hygiene during collection, storage, and feeding cannot be stressed enough! Potassium sorbate has been found to be the most effective method of preserving colostrum quality.
Remember- Colostrum management is key to reducing the incidence of calf disease (including scours). Plan ahead to avoid issues!