Take care when using dry cow tubes
Changes in the testing regime for antibiotic residues in milk have serious implications for dairy farmers.
Even farmers who follow the instructions on dry cow tubes to the letter have found themselves exposed to massive fines because of the increasing sensitivity of the tests being carried out by the dairy processors.
A far greater emphasis on eliminating antibiotic residues in food is forcing the pace of this change in the dairy industry over the last five years (see Dairy Health feature pages 6 and 7). Dry cow tubes are in danger of becoming the biggest casualty of this drive.
Permitted residue limits for the antibiotic or active ingredient in a given treatments are termed the maximum residue level or MRL. These are set by the Department of Agriculture and the EU.
However, a serious gap has opened up between the MRLs for the active ingredients in dry cow tubes and the residue levels for which milk processors are now testing.
This has happened because the tests used by processors are so sensitive they can identify antibiotic residue at well below the MRLs set down by the regulatory authorities.
The recommended withdrawal periods for dry cow tubes (the period for which milk must be withheld) usually ranges between six and eight milkings post calving.
But the length of these withdrawal periods are based on the higher residue levels allowed by the regulatory authorities and not the more sensitive tests employed by dairy processors.
This disparity puts farmers in a dangerous position, which they must be wary of now as they dry cows off.
Once cows calve next spring they must either trust the recommended withdrawal periods cited by the manufacturers or hold milk back for longer, just to be on the safe side.
The financial implications are serious where dairy farmers fail a test for antibiotic residues in milk.
Suppliers could be liable for fines of up to €9,000 under some processor contracts.
This issue raises a number of serious questions for the dairy industry:
1.Are the withdrawal periods set out by the manufacturers of dry cow tubes adequate, given the greater sensitivity of modern antibiotic residue testing?
2.Should withdrawal periods for dry cow tubes be increased to reflect the increased sensitivity of the tests used by processors?
3.Should milk processors who are also selling dry cow tubes inform their suppliers that the products' recommended withdrawal periods may not be sufficient to pass the dairy's residue tests?
4.If a farmer follows the advice on animal health treatments – vis-a-vis its administration and withdrawal periods – has he/she a legitimate expectation that his/her cow's milk will be free of antibiotic residue?