Pregnancy, ovulation, and ovarian function in dry or lactating cattle can be determined by a rapid, inexpensive, laboratory test for the hormone "progesterone."

Cattle should calve at 12-13 months intervals for maximum profit and production. Pregnancy may be determined 19-24 or 44-48 days after breeding by means of the rapid, inexpensive, assay of the naturally occurring steroid hormone "Progesterone." This is possible because each ovulation is accompanied by the formation of a Corpus Luteum in the ovary. The Corpus Luteum (CL) produces progesterone until the CL is reabsorbed. This occurs 14-18 days later if she is not pregnant. Therefore, the progesterone concentration in the milk and blood will rise shortly after ovulation and fall just before estrus in a non-pregnant cow. However, if the cow is pregnant, the progesterone concentration will remain high throughout pregnancy. This test also is very useful in determining whether bison are pregnant.
 

Progesterone testing has been found to be 98-99% accurate in predicting that a cow  IS  NOT  PREGNANT, because a cow with a very low progesterone concentration (0.1ng/mL) more than a few days after ovulation, cannot carry a fetus to term. However, a high progesterone concentration (1.5ng/mL or more) is only 85-88% accurate in predicting that a cow  IS  PREGNANT. This is because certain ovarian disorders will result in a high progesterone concentration, the cow may abort after the sample is drawn, or the cow may have an abnormally long or short cycle, resulting in the sample having been drawn at the wrong time. Drawing the sample at the wrong time is the major source of error in this testing.  Please collect the blood or milk when you would normally expect the cow to come into heat.
 

The progesterone test can also be used to detect certain ovarian problems, including the inability to ovulate and forms functional CL. If the progesterone concentration is not very low at the time of breeding or AI, or is not high seven days later, the cow probably needs veterinary care. A major purpose for progesterone testing is the early identification of those cows especially in need of veterinary reproductive care.
 

Note that a cow in heat may have a high progesterone, which means that she is not about to ovulate, regardless of her behavior. Similarly, some cows show no signs of heat, even when they are about to ovulate. Progesterone testing can be used to identify both of these conditions.

Milk samples should be sent to us in our hard plastic vials, which contain a very small amount of DHIA preservative. Serum (blood) samples should be sent in the same tubes, but without preservative.

We also provide endocrine (hormone) testing for many other species, including horses, and llamas.

                            PROGESTERONE $20.00

Rocky Mountain Instrumental Laboratories, Inc.
108 Coronado Ct.
Ft. Collins, CO 80525

970-266-8108
303-530-1169
 

LAST MODIFIED: 19 JANUARY 2008HOME