Milk Progesterone Test Research Articles

The milk progesterone test as an aid to the diagnosis of cystic ovaries in dairy cows.

Two field trials were carried out by five experienced veterinary surgeons to evaluate the milk progesterone test as an aid to the differential diagnosis of cystic ovaries in dairy cows. Of 200 cystic cows, 71 per cent were diagnosed clinically as follicular and 29 per cent as luteal cases; 80 per cent of the cases occurred in the six winter months November to April. The progesterone assay indicated that the diagnosis was correct in 84 per cent of the follicular cases but only 54 per cent of the luteal cases. Seventy-four per cent of the confirmed cystic cases responded to treatment within two weeks according to milk progesterone tests and there were no significant treatment differences. Overall, 80 per cent of the cows became pregnant on average 38 days after treatment having received an average of 1.70 inseminations each. Milk yield data in the first trial indicated that the cystic cows were not significantly higher yielders than their herd-mates.

On-Farm Milk Progesterone Tests

Results from milk progesterone assays can provide ovarian information, making it possible to monitor the reproductive status of the cow. Rapid, simple, and accurate on-farm milk progesterone tests are commercially available. Procedures for performing milk progesterone tests are specific for each test; however, principles of testing are similar. On-farm tests are designed to determine the relative progesterone concentration (“high” or “low”) rather than obtaining a precise concentration. Evaluation of results is based on either a color or agglutination reaction with comparison to known standards. Potential uses of progesterone testing in a reproductive management program are: 1) identifying errors in detection of estrus, 2) predicting time of estrus, 3) assisting in pregnancy diagnosis, 4) differentiating types of ovarian cysts, and 5) evaluating response to endocrine therapy.

Sensitivity and Specificity of Commercially Available Cowside Milk Progesterone Tests

The levels of progesterone in milk have been determined to accurately reflect the secretory activity of the corpus luteum in the cow. As an adjunct to rectal palpation the measurement of progesterone may be used to aid the diagnosis of reproductive abnormalities, pregnancy or return to estrus. Commercial kits utilizing the rapid enzyme-immunoassay (EIA) technique are being produced, which will allow veterinarians and producers to test milk progesterone levels at "cowside."

The evaluation of a new rapid milk progesterone test as an aid to improving dairy herd fertility

A new enzyme-amplified immunoassay (AELIA tm) for the measurement of progesterone in bovine milk has been developed which offers advantages over the radioimmunoassay (RIA) methods currently in use. The benefits of this new system include the use of monoclonal antibodies and an enzyme-amplification system which results in a rapid yet highly sensitive test that is ideally suited for use in veterinary laboratories. This paper describes a trial using this new system for the confirmation of oestrus and for the determination of pregnancy 24 days after insemination. Accuracy of interpretation was slightly improved using the AELIA tm technique which suggests that this new method provides a suitable alternative to the RIA systems currently in use. The speed and sensitivity achieved using the AELIA tm provides great potential for its use as an integral part of a herd fertility scheme.

Cow-side milk progesterone testing

Cow-side milk progesterone tests are effective in determining the presence of an active corpus luteum (CL) on the ovary. The test is best used as an adjunct to the Preventive Herd Health Program (PHHP) as a means of identifying cows that have not yet been detected in heat and are candidates for synchronization with prostaglandin (PGF). Several test kits are on the market, and all involve similar chemical principles. However, each test has its own protocol, so read and follow directions EXACTLY. A "control" or "sample" must be run with each test for comparison.; Dairy Day, 1987, Kansas State University, Manhattan, KS, 1987

The use of an on-farm milk progesterone test for the early identification of non-pregnant cows

The concept of using the concentrations of progesterone in milk for pregnancy testing became a commercial reality in 1975. Although this has proved to be a highly efficient method of identifying non-pregnant cows earlier than can normally be achieved by manual examination the results are not available in time for the first return-to-service period. The development of an enzymeimmunoassay technique by MAFF has resulted in the production of simple colour-change tests suitable for use in a practice laboratory or by the farmer in the convenience of his own office. The main advantage of an “on-farm” test is that the results are immediately available to the herdsman.

Use of an Elisa Milk Progesterone Test as an Aid to Oestrus Prediction in Dairy Cows

Oestrus detection in dairy cows has been the subject of many studies and various methods of improving oestrus detection have been investigated and reviewed by Boyd ( 1984). Poor oestrus detection will extend the calving to conception interval by prolonging both the calving to first service and first service to conception intervals (Eddy 1980). The availability of a commercially produced enzyme immunoassay (EIA) test kit (Ovucheck; Cambridge Veterinary Sciences) stimulated the setting up of trials to study oestrus detection rates and detection efficiency after first service. This paper reports the results of these trials. Trial 1 demonstrated that the E.I.A. for progesterone could be readily performed in the practice laboratory and Trial 2 demonstrated that similar improvements in accuracy and detection rates could be achieved by alternate day sampling. Oestrus detection remains a problem in many large dairy herds using artificial insemination and these trials demonstrate a place for oestrus prediction using E.I.A.

Milk progesterone levels in cows with normal or prolonged estrous cycles, referenced to an early pregnancy diagnosis.

Progesterone levels in skim milk sampled from 17 Pregnant and 39 non-pregnant cows three times weekly for 4 to 9 weeks after insemination were measured by an enzyme immunoassay. The lengths of estrous cycle in non-pregnant cows were 19 days in 8, 21 days in 14, 22 days in 1, 23 days in 3, 26 days in 3, and 30 to 60 days in 10 cows, respectively. A significantly lower (p<0.01) progesterone level of skim milk in non-pregnant cows, as compared with the level in the pregnants, was observed only on the day of estrus. The milk progesterone contents 2 days before and after the estrus were high enough to indicate the active corpus luteum function. In the 10 cows which returned to estrus 30 to 60 days after insemination, an occurrence of the embryonic death after 20-22 days after the serivce was suspected. The variation of the length of the estrous cycle as well as the occurrence of embryonic mortality could be most probable cause of the false positive diagnosis of pregnancy when the milk progesterone test was applied on the 20th or 21st day after insemination.

Use of milk progesterone enzyme immunoassay for early pregnancy diagnosis in cows

An enzyme immunoassay using β-galactosidase as the tracer was applied to determine milk progesterone level in cows. The novel method was reliable and practicable and required only a spectrophotometer and a centrifuge as major equipment. The milk progesterone enzyme immunoassay successfully diagnosed early pregnancy in cows. Milk samples were collected from 268 Holstein-Friesian cows in commercial dairy herds on 20, 21 or 22 days(usually 21 days) after insemination. Progesterone level in skim milk higher than 1.0 ng/ml indi-cated pregnancy. Pregnancy was confirmed by rectal palpation on 60 to 120 days after insemination. The accuracy of the milk progesterone test was 60.0 % ( 132 220 ) for a positive diagnosis and 100 % ( 48 48 ) for a negative result. A high incidence of embryonic death, 27.9 % ( 51 183 ), may have reduced accuracy for a positive test result. The enzyme immunoassay may be an alternative to radioimmunoassay in milk progesterone analysis for pregnancy diagnosis.

The costs and benefits of pregnancy diagnosis in dairy cows: A simulation model

An evaluation of the effect of pregnancy diagnosis on calving intervall is made using a computerised simulation model. Three different methods of pregnancy diagnosis are assessed (milk progesterone test at 24 days after service, rectal palpation test at 44 days and a rectal palpation test at 65 days post-service in combination with a treatment of cows diagnosed as not pregnant with prostaglandin or a heat-mount-detector). When the interval between insemination and pregnancy diagnosis is short, when the accuracy of a pregnancy test is relatively low, the use of a heat-mount-detector is preferred to the treatment with prostaglandin on cows diagnosed as not pregnant while, at later stages of pregnancy, it is better to use prostaglandin.

Factors Affecting Accuracy of Pregnancy Diagnosis in Cattle

When pregnancy was diagnosed by concentration of progesterone in milk 23 days postinsemination in 3014 cows, 76.9% of positive and 93.8% of negative diagnoses were confirmed by uterine palpation or return to estrus. Agreement between diagnosis by uterine palpation and diagnosis by milk progesterone test increased for at least 50 days after insemination. Accuracy of laboratory diagnosis of pregnancy increased as concentration of progesterone in the milk sample increased, making it possible to identify cows likely to return to estrus by a low concentration of progesterone in milk 23 days after insemination. There were 352 cows (11.7%) for which concentration of progesterone in the milk sample collected on the day of insemination was higher than normal during estrus. Exclusion of these cases increased the accuracy of pregnant diagnosis by 7.1% and not pregnant diagnosis by 3.1%.From a pragmatic viewpoint, pregnancy diagnosis by concentration of progesterone in milk was accomplished most effectively by quantitative assaying of only one sample collected 23 days after insemination and assigning to the absolute concentration of progesterone a probability that pregnancy will be verified after 50 days or more of gestation by uterine palpation.

Use of a milk progesterone test to check the detection of oestrus in cattle on a state farm in Tunisia

Summary The ‘milk progesterone test’ was used to find out how many cows were inseminated at the wrong moment (luteal period) of the oestrous cycle as a result of poor heat detection. From milk progesterone data it was concluded that 16. 1 per cent of the inseminations were performed during the luteal period. Heat detection appeared to be one of the factors which had te be improved in order to obtain better fertility results in a large dairy herd (300 cows) at a Tunisian state farm.

The Time of Detection of Oestrone Sulphate in Milk and the Diagnosis of Pregnancy in Cows

SUMMARY Oestrone sulphate (ES) was measured in the whey fraction of milk in 36 high-yielding Friesian cows between days 39 and 105 after insemination to determine the time in gestation when ES was consistently present. Progesterone, fat and protein concentrations in milk were also determined. ES concentrations in pregnant animals were low until day 80 but increased thereafter. ES was registered in all 18 samples tested after day 100 and 15 samples were scored correctly as positive and three were doubtful. Milk progesterone concentration, and fat and protein contents were relatively constant throughout. There was no correlation between the four variates examined, and no significant effect of sex of the foetus on ES concentration. The possibility is discussed of using a milk ES test after day 100 to provide laboratory confirmation of cows diagnosed pregnant on day 24 by the milk progesterone test.

Milk Progesterone Testing: Application to Herd Management

A commercial pregnancy testing service for cows became available to United Kingdom dairy farmers in 1975. The service met an immediate demand from farmers attempting to reduce losses due to delayed conception, $1.20 per cow per day, and after 18 mo approximately 5% of cows were being tested. Approximately one in six (16.5%) of the cows tested, which had not been detected in estrus by 24 days after insemination, were negative to the test; monthly variation was in the proportion of negative tests. Accuracy was 100% for the negative tests in herds where cow identification was good, and 85.2% for positive tests mainly because of fetal loss and insemination during the luteal phase.Other applications of the milk progesterone test in improving herd management are in limited use. These uses, which include the confirmation of estrus, fertility monitoring, and clinical applications, are of value to veterinarians and others in investigating subfertile herds or problem cows but, because of cost, are unlikely to find widespread application.

Use of the Milk Progesterone Test for Pregnancy Determination

SUMMARY A pregnancy testing service using the milk progesterone test has been available to dairy farmers in the United Kingdom since 1975. After three years operation, more than 100 000 cows a year are being tested and 5.6% of the farmers in England and Wales are using the service. The service is used proportionately more in larger herds (median herd size is 76 cows) and in autumn-calving herds. The percentage of negative tests rose to 20.0% in the third year, although there was considerable seasonal variation. A sample of large herds using the service found average accuracy rates of 84.5% and 97.0% respectively for positive and negative tests. A highly significant correlation ( r = + 0.84) was found between the proportion of positive tests in a herd and the accuracy rate of these tests. These two factors, and analysis of insemination interval data, are good indicators of herds requiring veterinary investigation.