Signs and Stages of Normal Parturition PDF

Signs and stages of normal parturition Presented by Dr/ Mohamed Wagdy Rezk Mansour Lecturer of Theriogenology Theriogenology department Faculty of veterinary medicine University of Sadat City [email protected] The exac...

Signs and stages of normal parturition Presented by Dr/ Mohamed Wagdy Rezk Mansour Lecturer of Theriogenology Theriogenology department Faculty of veterinary medicine University of Sadat City [email protected] The exact time of parturition can not be easily determined. Signs of approaching parturition The exact time of breeding or mating from the breeding records facilitates the determination of the date of parturition 1. Relaxation of the pelvic ligament -Relaxation of ligaments especially sacro-ischatic it is seen in late pregnancy becoming more pronounced as birth approaches due to the increased action of estrogen and relaxin hormones secreted from placenta. -The cow’s tail head may appear to be raised and the gluteal muscles sunken. - N.B. In Mare the muscle of the crop too much so relaxation of pelvic lig. Not clear like cow. 2.Enlargement and edema of perineal region (Vulva and hind quarter). 3.Enlargement and edema of udder Gradual enlargement and edema of udder (2 weeks before parturition in pluriparous cow) but in heifer (2-3 month before parturition). Waxing: bead like deposition of waxy seal or material at the end of teat orifice and occur in mare before parturition 24-36 hrs. 4. Strings of mucous appear from vulva 10-15 days before parturition. 5. Liquefaction of cervical seal (plug) in the last hours before parturition Methods and on-farm device to predict calving time in cattle Calving tail sensor: 2 hours before calving receive a text message (SMS) - 30 days battery life, easy charging via USB interface.  Theories of parturition 1.Aging of the fetal membrane theory. 2.The foreign body theory. 3.Uterine limitation theory. 4.Failing nutrient theory. 5.Central nervous system control. 6.Uterine contraction theory. Placental aging Fetal hypothalamus Nutritional failing Uterine restriction to growth Accumulation waste product Fetal pituitary ACTH Fetal adrenal Progesterone Cortisone Adrenal fetal theory Placenta 17α hydroxylase Estrogen N.B) In mare, dog and cat, the main source of the relaxin hormone is the placenta Cholesterol Pregnenolone Progesterone 17α Hydroxylase Cortisol Androstenadione Estrogen  Estrogen The effect of estrogen was three folds: 1. Estrogen has a direct effect upon myometrium increasing its response to oxytocin. 2.Altering the structure of the collagen fibers in the cervical wall causing softening of the cervix. 3. Act on cotyledon-caruncles complex and stimulate the synthesis and release of PGF2 α.  1. Luteolysis CL. PGF2α 2. Softening and dilatation of the cervix and initiation of the uterine contraction. Ferguson reflex Fetus engaged into the cervix and vagina stimulate sensory receptor causing the release of large amount of oxytocin 1. Myometrial contraction. 2. Release large amount PGF2 α which stimulate uterine contraction.  Stages of normal parturition Parturition is really one continuous process, but for the purposes of description it can be divided into 3 stages which are based on the changes occurring during the normal course of events. 1. The opening or dilatation stage 2. The expulsive stage 3. Expulsion of fetal membrane Preparatory changes 1. Enlargement of udder, distention of teat with colostrum. 2. Edema and enlargement of the vulva. 3. Clear vaginal mucous (liquefaction cervical seal) 24-48 hrs before parturition. 4. Relaxation of the pelvic ligaments and sinking of croup muscles. 5. By rectal palpation, the fetal head and limbs can be felt at the maternal pelvis. N.B) In mare occur teat waxing(bead like deposition of waxy seal at the end of teat).  1. The opening or dilatation stage -Start with the birth pains and ends with the rupture of the fetal sac -Relaxation and opening of the cervix. -Active contraction of the uterine muscle and begin at the cranial part of the uterus. - Chorio-allantois enter vagina. -Cattle 2-3 hrs heifer 6-8 hrs -Mare 1-2 hrs -Small ruminant 4-8 hrs Intact amniotic sac outside of the vulva and ruptured chorioallantoic membrane pending on the udder.  2. The expulsive stage - Start when the cervix completely opened and one of the sac is ruptured or start to be ruptured and ends with expulsion fetus. -Fetal extremities were been pushed in the cervix initiates: A) reflex stimulate secretion of oxytocin B) Initiates birth pain or straining or deliver pain due to contraction of (abdominal ms.&diaphragmatic ms.&closure of epiglottis). -Cattle ½ - 2 hrs heifer 3-4 hrs -Mare 10-15 min. The foetal feet (forelimbs) progressing outside the vulva after the rupture of the second water bag which lubricate the birth canal  3. Expulsion of fetal membrane -Placental circulation lost. -Separation of fetal membrane. -Uterine and abdominal contraction continue. -Placenta is expelled. -Cattle 6-8hrs (within 12 hrs.) and longer than 12hrs considered retained - Ewe and doe within 3-4 hrs after the last lamb. - Mare ½- 2hrs and longer than 2 hrs. it considered retained - Bitch within 2hrs or may passed after each puppy or after group of puppies or at the end of whelping. Retained Placenta The dam eating her placenta  Premature Induction of parturition in cow - Corticosteroids (15-30 mg dexamethasone)+ PGF2α (3cm Estrumate) + Estrogen (Folone)  Premature Induction of parturition in Mare - Oxytocin is the drug of choice (40-60 IU) - 100 mg dexamethasone + 1ml PGF2α ( Estrumate) - N.B) Large dose of Estrumate or lutalyse (PGF2α) in mare leads to (sever sweating. Harried respiration, muscular tremors and colic). - Dose of (PGF2α) in mare 1/5 dose of cattle.