Changes

This is a simple, rapid and inexpensive test that may be performed on farm as part of a calf health investigation. However, with a sensitivity and specificity of approximately 80%, it is most appropriately used as a herd level test. It is recommended that a minimum of 12 samples are taken to allow interpretation on the herd level. It is important that the calves sampled are clinically healthy as dehydration can elevate the total protein levels increasing the proportion of false negatives results.

This is a simple, rapid and inexpensive test that may be performed on farm as part of a calf health investigation. However, with a sensitivity and specificity of approximately 80%, it is most appropriately used as a herd level test. It is recommended that a minimum of 12 samples are taken to allow interpretation on the herd level. It is important that the calves sampled are clinically healthy as dehydration can elevate the total protein levels increasing the proportion of false negatives results.

After blood sampling into a plain tube, the blood can be left to clot at room temperature and then by way of transferring the serum with a pipette or syringe, the total protein can be measured using a refractometer. Alternatively a centrifuge may be used. Using a cutoff of 55 g/l, 4/12 or greater is sufficient to say failure of passive transfer is problem on the farm. If the result is 2-3/12, then sampling of further calves is recommended. On smaller herds where 12 calves may not be available at one time, samples should be taken as appropriately aged calves become available until 12 are sampled.

After blood sampling into a plain tube, the blood can be left to clot at room temperature and then by way of transferring the serum with a pipette or syringe, the total protein can be measured using a refractometer. Alternatively a centrifuge may be used. Using a cut off of 55 g/l, 4/12 or greater is sufficient to say failure of passive transfer is problem on the farm. If the result is 2-3/12, then sampling of further calves is recommended. On smaller herds where 12 calves may not be available at one time, samples should be taken as appropriately aged calves become available until 12 are sampled.

====3. Zinc sulphate turbidity test (ZST)====

====3. Zinc sulphate turbidity test (ZST)====