Pregnancy Diagnosis in Cattle 2024 PDF

The University of Georgia College of Veterinary Medicine College of Veterinary Medicine Pregnancy Diagnosis in Cattle Roberto A. Palomares, DVM, MS, PhD, DipACT  Learning Objectives Describe the different stages of fetal development during bovine pregnancy Discuss the p...

The University of Georgia College of Veterinary Medicine College of Veterinary Medicine Pregnancy Diagnosis in Cattle Roberto A. Palomares, DVM, MS, PhD, DipACT  Learning Objectives Describe the different stages of fetal development during bovine pregnancy Discuss the physiological changes in the reproductive tract during the gestation of the cow Compare the methods of pregnancy diagnosis in cattle (advantages and disadvantages). Indicate the cardinal signs of pregnancy in the cow, and how they are evidenced by transrectal palpation and ultrasound Explain the principles of the chemical methods of pregnancy diagnosis in the cow (pregnancy associated glycoproteins)  Why to diagnose pregnancy? To detect non-pregnant cows (Re-breed, Treatment or culling). Measure the success of a reproductive management. Early detection of reproductive problems. To resynchronize non-pregnant cows.  Impact of Erroneous Results False Positive: Animal will remain non-pregnant unproductive in the herd. False negative: Receive PGF2α, result in ED (losses $550–800). Culling pregnant cows  Observation A. Non-return to estrus (18-24 d) B. Weight gain C. Udder development Presumptive diagnosis Easy, Non-invasive, Little training Lack sensitivity & specificity  A. Cessation of estrus cycle “Non-return to estrus” False positive:  Cystic ovarian disease  Hydrometra: More common in does (3-20%)  Metritis, pyometra, mummies.  Nutritional Anestrus.  Poor heat detection False negative:  Some pregnant females show behavioral estrus.  Can lead to use of PGF2α or AI Direct Methods Trans-rectal Palpation Most common and accurate method in cows. Sensitive, specific, economic, immediate results, aging. Useful as early as 32 days depending on: DVM experience, age and size of dam. Cardinal signs (4) Secondary signs or indications (5) Systematic exam !!!  Cardinal Signs   1. Membrane slip (MS) 1. Amniotic vesicle (AV) 3. Placentomes 4. Fetus  1. Chorioallantoic Membrane Slip Compressing the horn between the thumb and forefingers. Lifting the uterus, allows the membranes to slowly slip from the grasp uterine wall. (35-100 d) @ 35 d in the gravid horn. @ 60 d in the non-gravid horn.  2. Amniotic Vesicle (AV) Contains the developing conceptus and amniotic fluid. Palpable at 28 dpc in heifers & 32 dpc in cows. (30-60 d). Spherical, turgid, fluid filled structure, free floating. Detected by encircling the uterine horn between thumb & fingers.  2. Amniotic vesicle By 60-65 d: Less turgid and difficult to recognize (starts to elongate). Fetus becomes palpable. Be careful before 40 dpc because the heart is external. It can be ruptured.  2. Amnionic vesicle Dpc Size Fingers Tugidity 35 d 1-1.5 cm 1 turgid 42 d 2-3 cm 2 48 d 3.5-5 cm 3 52 d 5.5-7 cm 4 58 d 75 mm 5 62 d 90 mm lose turgidity 65 d 105 mm  3. Placentomes Endometrial caruncles + fetal cotyledons. 75-120 placentomes. Formed early in gestation and palpable by 75-80 days  3. Placentomes Size increases as gestation advances & varies with location. Larger in the middle of gravid horn. More consistent in size immediately cranial to the cervix.  3. Placentomes False positive: After fetal death remain palpable for a variable time. Mistaken of ovaries (similar size in 4-5 mo pregnancy). Palpate > 3 placentomes !!! False negative: When uterus is completely descended (5-7 mo). Search for other signs of pregnancy. Identify nongravid uterus before saying “non pregnant”.  4. Fetus Palpable @ 60 d (AV looses turgidity and fetus increases size) Early: fetus can be grasped. Later: fetus can be balloted (re-bounce). Nose -top of forehead 70 d 15 mm 80 d 35 mm 90 d 55 mm 100 d 90 mm 120 d 105 mm  4. Fetus 2nd - 4th mo: Free floating, firm object within the fluid filled uterus. 5th 6th mo: Fetus increases weight. Fluids pull the uterus ventrally and cranially. Fetus rests on abdominal floor (descending). 7th-9th months: Fetus continues growing, it positions closer to the maternal pelvis. (ascending). www.ucd.ie  4. Fetus Fetal size used for determining the age of gestation German (7 mo) Brittany (6 mo) Beagle (5 mo) Cat (4 mo) Rat (3 mo)  4. Fetus Falsepositive: Another structure is mistaken for a fetus. Dorsal sac of the rumen Left kidney Uterine tumors Enlarged lymph nodes Connective tissue after Surgery or obstetric trauma Fat necrosis (effect of Fescue) Mummified or macerated fetuses. False negative: more likely at 5th-7th mo.  Secondary signs of pregnancy a)- Asymmetry of the uterine horns b)- Fluctuance of uterine wall (fluids) False positive: hydrometra, mucometra, pyometra, delayed postpartum uterine involution.  c)- Fixation of cervix: Uterus retraction until 70-75 d. At 90 d it is difficult to retract. False positive: hydrometra, mucometra, pyometra, maceration and mummification, adhesion after C-section, large uterine or ovarian tumors (Lymphosarcoma, GCT).  d)- Fremitus of middle uterine artery As gestation advances blood supply to the uterus increases. Increased size detectable in heifers 75d and cows at 90d. (130 d) Increased blood flow, Increased size & thinning of the wall. (1500 mm Hg) It persists for several days after abortion or parturition. Present on other conditions (mummies and fetal macerations).  e)- Presence of a CL Do not palpate the ovaries if the cow is pregnant. In some cases useful to examine ovaries if uncertain after palpating the uterus. CL always in ovary ipsilateral to pregnant horn. Pyometra: persistence of CL & fluid accumulation within the horns.  Stage of gestation AV Membrane slip Fetus Placentome 32 d X X X 1 finger 37 d X X 1 finger 45 d 2 fingers X X  Stage of gestation AV Membrane slip Fetus Placentome 48 d X X 3 fingers 52 d 4 fingers X X 60 d Softens X Mouse  Stage of gestation AV Membrane slip Fetus Placentome 75 d X 0.5 cm 80 d X 0.5-1 cm 90 d X Rat Dime  Stage of gestation AV Membrane slip Fetus Placentome 120 d X X 2 cm $1/4 150 d X X Descending 3cm $1/2 180 d X X 4 cm Descending  Stage of gestation AV Membrane slip Fetus Placentome 210 d X X 5 cm Ascending 240 d X X 6-8 cm 270 d 8-12 cm X X  Trans-rectal Ultrasonography (TRUS) Minimally invasive, accurate, effective and quick. Accurate @ 24-26 dpc. Heartbeat detectable in viable embryos. Heifers 3 days earlier than cows  Trans-rectal Ultrasonography (TRUS) Advantages:  Earlier (24-26 d post AI) than TRP. Around 7 days earlier.  Accurate, Sensitive and specific.  Not been implicated as a direct cause of pregnancy loss Embryo viability (heart beat) and defects Separation of chorion-allantois Flocculent amniotic fluid No heart beat Amorphous appearance Aging the pregnancy 29 d 35 d  Detection of Twin Pregnancies 39 d twin pregnancy 26 d twin pregnancy  Fetal Sexing Male – 70 days  Genital tubercle Cattle(59-80d). Female – 65 days Diagnosis of Ovarian or Uterine Pathologies.  Which TRUS findings should be considered ? Accurate early pregnancy diagnosis must include the Embryo and Heartbeat.  Fluid in the uterus or Cl ovary: Not evidence of pregnancy. Decrease accuracy. Fluid in the lumen CL on the ovary Ovary and uterus 21 d post AI  B- Indirect Methods - Progesterone Test - Pregnancy Associated Glycoproteins Early Pregnancy Factor Interferon Stimulated Genes   Progesterone Test If the cow is pregnant, P4 keeps high during the whole gestation. In blood or milk (>2 ng/ml). Indicates presence of CL @ 24 d after AI. RIA or ELISA Reliable ID Non-pregnant cows. Low specificity and positive predictive value for Pregnancy. High costs ($ 25-30 /sample) Not Practical !!!  Embryo Present in Uterus Ovulation Ovulation CL Progesterone (P4) is maintained high False Positive: Variation in length of estrus cycle (24d) Poor heat detection (AI during luteal phase). Cysts, Pyometra. Late Embryonic Death 17-40 d, prolonged CL Pregnancy-Associated Glycoproteins PAGs are aspartic proteinases expressed by the ruminants placenta Senger, 2012 Senger, 2012  PAGs Exocytosis of granules containing PAGs into the maternal circulation.  B- Bovine Pregnancy-Specific Protein B bPSBP test ELISA using blood  Labeled for >28d in cows and 25 d in virgin heifers (starts d 15- 22 )  Detected until 73 dpp. 60-day VWP no False+ due to residual PSPB  Low cost ($2.50) and fast turn around (24h)  High Accuracy identifying non-pregnant cows False Positive:  Similar PSP-B levels in pregnant cattle vs. animals with pregnancy loss  PSPB can persist in cows that had suffered pregnancy loss.  Higher pregnancy loss reported in cows using PSPB vs TRUS.  PSPB long half-life in maternal circulation: 7.2 days  Practical protocol for Chemical test + Palpation TRUS, Re-synch Open Cows AI GnRH 0 10 20 30 40 50 60 70 80 Blood sample Ultrasound / Palpation 28 days post AI Faster Resynchronization. Help to reduce calving intervals (