The Grange Labs are part of the Teagasc integrated Research, Advisory & Education Services. The services listed here include a wide range of blood analyses. The Lab can also supply other analyses not specifically mentioned for example liver Cu, milk I etc).

Mineral related, metabolic & nutritional disorders of cattle & sheep include:

Technical Notes for Vets & Nutritional Consultants are available online. A Reference Manual for Vets & Advisers ("Control of Mineral Imbalances in Cattle & Sheep"), is available free online also. Hardcopies of the Manual are available free to Teagasc Advisers, Researchers & Teachers.

Vets & consultants in private practice may have a hardcopy at a cost of 60Eu/copy). Corporate clients will be charged 80Eu/copy.

Lab reports: Farmers rely on the expertise of Vet Practitioners & other animal health professionals to diagnose, treat & advise on control strategies. Expert blood analysis, & its interpretation, can play a part in the systematic elimination of causes of clinical or subclinical problems.

The format of a report from a top-class lab should be comprehensive. It should include individual test results for each animal, a comment on each result where high or low values are recorded, range of results (average, minimum & maximum), reference values (breakpoints) used to assess each test, herd/flock group assessment. The test report should include a computer assessment & summary of the test results.

Nonclinical deficiencies: Low blood mineral values can arise in apparently healthy herds (nonclinical deficiency). This phenomenon is widespread. Thus, mineral imbalance can be coincidental (rather than causal) in "problem" herds or flocks. In such cases, correction of the imbalance (which can be expensive if veterinary supplements are used) does not improve farm profits. Therefore, careful professional help is needed to interpret the blood results against the history of the herd or flock.

Two forms of additional support are very helpful to diagnose and control outbreaks in serious animal health problems:

(1) Diagnostic comment, veterinary advice on control measures & Advisory Support: Based on the analysis report, specialists can provide an extra report which gives veterinary diagnostic comment, specific recommendations & control measures on an individual herd, or flock basis.

(2) Additional support from the Teagasc County Advisory Service: Farmers who are full paid-up Teagasc Clients may also request support from their Teagasc County Office. This support may include a farm visit by an experienced Adviser, and the analysis of soil and feed samples.

Veterinary practitioners are responsible for the diagnosis of the cause(s) of animal disease. Blood testing is a valuable diagnostic support service for vet practitioners. As the signs shown by affected animals can range from clinical to sub-clinical, the testing of blood samples can be used to verify the clinical diagnosis or to monitor the effectiveness of control measures. To reduce / avoid losses in cases where imbalances in nutrients & minerals affect livestock, problems need to be detected quickly, diagnosed accurately & corrected effectively. Modern farming practices place increasing demands for production on animals. Highly productive animals are under heavy metabolic stress. Consequently, the requirements for nutrients & minerals in animal diets have increased. 

BLOOD is the standard tissue used internationally for accurate routine assessment of the mineral status of cattle & sheep. For milk to replace blood as the standard sample for this purpose, levels of the relevant minerals in blood & milk should correlate very highly; unfortunately, in most cases, the correlation for a given mineral are very poor. One exception to this is the Milk Iodine (MI) test.

Milk Iodine (MI) Tests: These tests must be done in specialised labs on milk samples free of iodine contamination. The tests must be interpreted with caution. An MI value <50 ug/L may indicate a low iodine intake. Iodine-contamination of milk is common because many farmers use iodine-rich teat-dips & disinfectants. Thus, an MI value >50 ug/L can arise in cows whose bloods are severely low in iodine.

Blood Iodine tests: We examined many blood tests in earlier attempts to assess iodine-nutrition of cattle: total blood I (TOTI), protein-bound I (PBI) & thyroid hormones (T3, T4). We abandoned ALL of those tests in the late 1970s. They were not (and still are not) reliable to assess iodine status of ruminants. A highly accurate test of iodine status was developed in the mid 1980s - the plasma inorganic iodine (PII) test.

To assess iodine nutrition of cattle & sheep accurately, we advise assay of PII levels in 7-10 INDIVIDUAL blood samples. The PII test is more reliable than the MI test, but is time-consuming, labour-intensive & more expensive to do. Unfortunately, no lab in the State des the PII test now. The Veterinary Research Laboratory in Stormont (Belfast) used to run PII tests for vets in the Republic, but have discontinued that service because they could not cope with the numbers of samples.

Because the PII test is not available any more, veterinary diagnostic labs in the Republic offer only the MI, T3 and T4 tests. Consequently, because the wrong tests are being used, genuine outbreaks of iodine deficiency are being missed. Also, in herds with high inputs of iodine supplements, use of the wrong tests (MI, T3, T4, etc) is diagnosing iodine deficiency when such deficiency could not exist. The result is that feeds and supplements with a very generous iodine content are being wrongly blamed as providing inadequate iodine for the cattle.

Milk tests can NOT adequately replace blood tests for routine & accurate assessment of mineral nutrition of cattle & sheep. Bulk milk is easy to obtain; it can be analysed for multiple components. Analysis of bulk-milk can help to assess protein & fat levels, urea, ketones, antibodies, mastitis risk, etc. Some commercial Labs offer analysis of milk samples as an aid to investigation of mineral deficiencies in cattle & sheep. However, milk tests for nutritional major elements (such as Ca, Mg, Na & P), or trace elements (such as Cu, Se or I etc) are unreliable to assess the animals' status of these nutritional elements.

In 1997, Rogers did an exhaustive search of published veterinary literature (including Focus-on-Veterinary-Medicine) & online databases (including Medline). He also e-mailed several thousand members of the American Association of Veterinary Laboratory Diagnosticians, Beef List, Dairy List & colleagues in State Veterinary Diagnostic Labs abroad. He failed to find reliable scientific evidence that milk (whether from individual cows, or from the bulk-tank) can be used to assess accurately the mineral status of cattle & sheep.

Thus, in line with the advice from State Veterinary Labs abroad, we do not recommend mineral tests on bulk samples of blood or milk for that purpose.

In summary, analysis of 7-10 INDIVIDUAL blood samples provides the best practical assessment of the mineral status of a herd or flock. If one needs an ACCURATE assessment of iodine status, one should test 7-10 INDIVIDUAL samples from the problem group for PII. The T3, T4 and MI tests are NOT recommended for accurate nutritional assessment.

The MI test has no relevance to problems in calves, drystock, or cows in late pregnancy; such animals do not produce milk! In lactating cows, the MI test must be used with caution because iodine contamination occurs easily if there are iodine-containing compounds in the dairy. MI simply is NOT as reliable as PII to assess iodine nutrition of cows.

All tests, below, are available. Breakpoints used to interpret these tests are available online. Other tests are available on request.

*The test is no longer available in Grange. Veterinary lubricants, disinfectants and teat-dips can contain high levels of iodine. Take great care to avoid sample contamination with iodine. 

Profiles (analysis packages) available: For official research Grange offers great flexibility in the choice of blood tests.

The most popular profiles requested in the past (but no longer on offer to the public) for Cattle & Sheep were:

N.B.: Heparinised (green cap) samples are used for all blood tests,
except P*& Glu* (Fluoride, grey cap) & Haematology (B9H**, EDTA, Purple Cap)

There can be a major variation in blood values between animals in the same group. For a proper assessment of herd/flock status, we advise that 10 animals should be sampled & tested individually.

Avoid bulked-blood analysis: Some Labs analyse bulked-blood to reduce their workload and increase their profit margins. Bulk analysis (mixing 10 samples into 1 & testing the single sample) may be misleading & lead to errors in interpretation, diagnosis & control.

Blood sampling kits are available from the Lab. Each kit contains 10 vacutainers in a preaddressed package for ease of posting. Each test kit also has a Sample Detail Form. The sender should take great care to complete all questions on that form.

Milk sample containers (for I or urea) are available, if needed.

If researchers need to order Sampling Kits for blood or milk tests, see contacts, below. 

For best interpretation of the blood results, it is most important that the sender provides ALL DETAILS requested on the Blood Sample Detail Form: [service discontinued].

Specify the ANIMAL TYPE sampled:

If you sample more than one ANIMAL TYPE, specify the SAMPLE NUMBERS for each TYPE in the relevant box. For example if you sample 5 Dry Dairy Cows (samples #1-5) & 5 Calved Beef Cows (samples #6-10) on the same farm, put 1-5 in the Dry Dairy Cow box, & 6-10 in the Calved Beef Cow box on the Sample Detail Form.

Mineral supplementation has a marked effect on most minerals & related enzymes in blood. Therefore, take great care to document ALL supplementary mineral inputs in the months, weeks & days just BEFORE blood sampling.