Pregnancy Examination of the Cow : Pregnancy Examination of the Cow Dr.SAMIR MUDULI
ORISSA VETERINARY COLLEGE
BHUBANESWAR WHY ? : WHY ? The goal of any method used to do the pregnancy examination is to determine the pregnancy status with:
no false positives,
no false negatives,
determine the pregnancy as early as possible,
the ability to age the conceptus,
be able to determine the viability of the conceptus, and
possibly determine the sex of the fetus and
have the results immediately. Rectal palpation : Rectal palpation Currently, rectal palpation is the easiest, fastest, cheapest method, most accurate method that meets most of our goals.
Your goal in rectal palpation is to be 100% accurate at determining the pregnancy status 35 days post breeding.
You need to set your own standards though. If you cannot determine pregnancy until 45 days post breeding, then use that as your cutoff.
You may even try to determine if cows are not pregnant by palpation of CL2 and F20 and uterine tone at 18-21 days post-breeding. This would indicate that the cow has low progesterone and is coming back into heat at the expected time and therefore is not pregnant. Conversely, a corpus luteum on the ovary and no tone in the uterus 21 days post-breeding indicates high progesterone and the cow may be pregnant. It does not however guarantee that the cow is pregnant The Golden Rules of Rectal Pregnancy Exam : The Golden Rules of Rectal Pregnancy Exam You must examine the entire tract before declaring the cow open.
You must find one of the positive signs of pregnancy before you call a cow pregnant.
Pregnancy examination must always be the first step in your examination. If you are not sure, recheck the cow...maybe in a few minutes, maybe tomorrow.
The only positive signs of pregnancy in the cow are fetus, cotyledons/caruncles , amniotic vesicle, and fetal membrane slip. Slide 5: cotyledons on the placenta caruncles on the uterus Technique of pregnancy diagnosis by rectal palpation of a retractable uterus : Technique of pregnancy diagnosis by rectal palpation of a retractable uterus First feel the uterus for asymmetry. At 35 days of pregnancy the pregnant horn will feel slightly larger.
Second, feel for fluid in the larger horn. The fluid has a smooth velvety feel because the uterine wall thins during pregnancy. The fluid almost feels like a water balloon that is not totally full.
Third, You must systematically feel the uterus for the amniotic vesicle, the fetal membrane slip, or the fetus. (cotyledons will not appear until about 75 days). Although the CL3 is on the ipsilateral ovary 99.9 % of the time and it may help to identify the pregnant horn, it is not a positive sign of pregnancy. Always follow the golden rules of pregnancy diagnosis. Slide 7: Asymmetry of the horns. Quite a bit actually.Note the CL3 on ovary ipsilateral to the pregnancy Technique for pregnancy diagnosis by rectal palpation of a non retractable uterus -: : Technique for pregnancy diagnosis by rectal palpation of a non retractable uterus -: Try hard to retract the uterus and examine the entire tract. Try to slip anterior to the cervix and feel for a fetus or cotyledons/caruncles.
Other signs suggestive of pregnancy are fremitus, which is a hypertrophy of middle uterine artery. The middle uterine artery can be picked up in the broad ligament and moved around. There is a fluid turbulence that gives a 'buzz' feeling to the artery. You must rule out the external iliac. Slide 9: Do not confuse with the iliac artery, which is not moveable.If there is no corpus luteum present, the cow cannot be pregnant. How good are we at determining the presence of a corpus luteum? The middle uterine artery is in the broad ligament and movable Estimation of stage of pregnancy by rectal palpation : Estimation of stage of pregnancy by rectal palpation Why do you need to estimate the stage of pregnancy?
There may be lost records and you need to predict dry off dates.
You may need to stage pregnancy if records are not kept or a bull runs with the herd.
You may need to confirm AI dates, or an AI date may not match what you feel.
You may be asked to estimate parturition dates for beef herds. Technique : Technique Fluid is barely palpable at 28 days, although this is not a positive sign of pregnancy.
Amniotic Vesicle (this is not recommend for student palpation)
The AV can be palpated as long as 2 weeks after is crushed. This would be a case where you find a positive sign of pregnancy, but the cow is not pregnant. Amniotic Vesicle : Amniotic Vesicle Fetal Membrane Slip : Fetal Membrane Slip Be gentle, as you can damage a pregnancy by rough palpation)
32 -days thread 1 horn 45 -small string 1horn 60 -string 2 horns>70 -large string Cotyledons (actually the placentome, which is the cotyledon/caruncle unit) : Cotyledons (actually the placentome, which is the cotyledon/caruncle unit) You must rule out that you are not palpating an ovary by feeling at least 3 .
75 days pea size100 dime115 nickel125 quarter150 half dollar> 150 variable Fetus : Fetus The fetus descends out of reach from 3-7 months.
You can first feel the fetus at 55-60 days inside the AV.
To estimate an aborted fetus they are:2 months mouse3 months rat4 months small cat5 months large cat6 months beagle dog Fremitus : Fremitus Fremitus is not a positive sign of pregnancy, but can help staging.
At 5 months the artery ipsilateral to the pregnancy has fremitus.
At 6 months both the artery ipsilateral and contra- lateral to the pregnancy have fremitus.
At 7 months both arteries are large with fremitus and the fetus is ascending. Differentials in Pregnancy Diagnosis by rectal palpation : Differentials in Pregnancy Diagnosis by rectal palpation Failure to retract and no positive sign of pregnancy
found can be caused by:
Incompetence - this will diminish as your skills increase.
Failure to be complete
Granulosa cell tumor Signs of problems in pregnancy noted with rectal palpation : Signs of problems in pregnancy noted with rectal palpation Excess uterine tone,
relaxation of pelvic diaphragm,
gestation you palpate is not equal to the breeding date you are given (this could just be an error in the records though). Summary of Rectal Palpation for Pregnancy Diagnosis : Summary of Rectal Palpation for Pregnancy Diagnosis Establish the time you are confident in diagnosing pregnancy by rectal palpation.
Always be systematic in your examination.
Observe the golden rules of pregnancy diagnosis by rectal palpation Ultrasound : Ultrasound There are different types of machines available.
The most commonly used machines today are B-mode real-time, meaning that they produce an acoustic image in real time.
The usually range from 3.5 - 7.5 MHz,
With greater MHz you see more detail but have less depth penetration.
There is more depth penetration with lower MHz, but less detail. It is always a tradeoff.
These machines cost from $10-20,000. ULTRASOUND Image of a bovine conceptus and is identified as an elongated, fluid filled structure of the uterine horn. : ULTRASOUND Image of a bovine conceptus and is identified as an elongated, fluid filled structure of the uterine horn. Ultrasound image depicting an elongated (left) and cross-sectional (right)view of the non-pregnant uterus : Ultrasound image depicting an elongated (left) and cross-sectional (right)view of the non-pregnant uterus Milk progesterone assay : Milk progesterone assay This test is based on the milk progesterone concentration 21-24 days post breeding.
The milk progesterone parallels blood progesterone.
It is important to know that this can only be used with known AI or breeding dates and the test cannot be done randomly in a herd.
It is based on the fact that if progesterone is low 21 days post breeding then there is no chance that the cow can be pregnant.
Remember that a cow must have progesterone be pregnant. Therefore the test is 100% accurate at non-pregnancy diagnosis when the progesterone is low. If Progesterone is high 21 days after breeding the cow 'should' be pregnant : If Progesterone is high 21 days after breeding the cow 'should' be pregnant If Progesterone is low 21 days after breeding (or anytime) the cow cannot be pregnant. : If Progesterone is low 21 days after breeding (or anytime) the cow cannot be pregnant. Slide 26: However, if the progesterone is high, the test is only 80 % accurate at diagnosing cows pregnant.
This is because there may be mistakes and cows may be bred that are not actually in heat. These cows would therefore have high progesterone 21 days later, yet not be pregnant.
Also cows with short and long cycles can cause misinterpretation of the test. A false positive if breeding was not done at estrus. The progesterone 21 days later may be high and indicate a pregnant cow. The blue line indicates the 2 ng/ml threshold value for positive. : A false positive if breeding was not done at estrus. The progesterone 21 days later may be high and indicate a pregnant cow. The blue line indicates the 2 ng/ml threshold value for positive. Slide 28: THANK YOU