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Animal reproduction and obstetrics

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Animal reproductive anatomy
Animal reproductive anatomy
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Animal reproduction and obstetrics

  1. 1. SOKOINE UNIVERSITY OF AGRICULTURE DAH 0203: Animal Reproduction and Obstetrics BY DR. Isaac P. kashoma
  2. 2. DEFINITION • REPRODUCTION (from the Greek word, Reproducere “repeat to produce”) is the process of having babies, producing young. • OBSTETRICS (from the Latin obstare, "to stand by") is the medical specialty dealing with the care of all women's reproductive tracts and their newborn during pregnancy (prenatal period), at parturition and the postnatal period.
  3. 3. ANATOMICAL STRUCTURE OF REPRODUCTIVE ORGANS. A: REPRODUCTIVE SYSTEM OF FEMALE ANIMAL. Consist of two parts:  Supporting Tissues.  Proper reproductive organs.
  4. 4. 1: Supporting tissues Bones, ligaments and tendons. a) Bones: Sacrum, the two os coxae (Ilium, Ischium and Pubis). They form a cavity known as Pelvis
  5. 5. b) Ligaments and Tendons. Maintain the relationship of the pelvis and spinal column. 1) The dorsal and lateral sacroiliac ligaments which fasten the wing of the ilium to the lateral portion of the sacrum. 2) The sacro-sciatic ligament completes the lateral wall of the pelvic cavity behind and between the sacrum and coxae. 3) The prepubic tendon, the tendon of insertion of the two rectii abdominis, the external and internal obliques, the gracillis and pectini muscles.
  6. 6.  The pelvis is the smallest and most posterior of the three great cavities of the trunk.  Forms the cavity in which some of the female genital organs are contained  Prevents the passage of the fetus during pregnancy (before parturition).  Forms the canal through which the fetus passes during the act of parturition.  The caudal portion of the pelvic cavity is smaller in diameter than the cranial portion, however it is capable of dilating at the time of parturition to allow the passage of the fetus PELVIS
  7. 7. 2. PROPER FEMALE REPRODUCTIVE ORGAN.
  8. 8. 1: Ovaries.  Ovaries (2) are primary reproductive organ of the female and are suspended the broad ligament (mesovarium).  Oval (shape) with various sizes containing thousands of ova and only one ovum is usually released during each estrous cycle in cow  Two parts: cortex producing oocytes or egg cells, and Medulla made of connective tissue and blood vessels. 1. Ovary at rest, non- cyclic 2. Functional corpus luteum 3. Not easily palpable functional corpus luteum 4. Vacuolated corpus luteum 5. Polycystic ovary (follicular cysts)
  9. 9. 2: Fallopian tubes (Oviduct).  Fallopian tubes (Oviduct) helps to transport ova (fertilized eggs) to the uterus.  Oviduct is supported by the broad ligaments (Mesosalpinx).  Has three parts: a) Infundibulum: A funnel like of the oviduct. It connect the oviduct to the ovary, it has process finger like structures known as the fimbriae. b) Ampulla: Slightly wider portion and at the middle portion of the oviduct. c) Isthmus: Joining the uterine horn to the oviduct, it has half of the length of the oviduct.
  10. 10.  The oviduct is the site of fertilization and early cleavage.  Fertilization takes place in the lower portion of the ampulla (Ampullary isthmus junction) following which the fertilized ovum or ova enter the uterus. 3: Uterus.  Is a hollow muscular organ, Y-shaped, and is divided into two parts: body and uterine horns.  Uterine size varies with breed, age, parity, pregnancy and disease.  The uterus is suspended to the pelvic on either side by broad ligament.
  11. 11.  Uterine wall consist of three layers, the inner lining (Endometrium), the muscular layer (Myometrium) and the outer layer (Serosa).  Functions: site of semen deposition during Al, secrete fluid (uterine milk) which provides nutrients to the developing embryo, develops the maternal side of the placenta to nourish and protect the developing fetus.  Four basic types of uteri: 1. Bicornuate uterus (sow, cow, doe and ewe) has small uterine body and two long uterine horns. 2. Bipartite uterus (mare) has a prominent uterine body and two uterine horns. 3. Duplex uterus (rat, rabbit & guinea pig) has two uterine horns each with a separate cervical canal opening directly into the vagina. 4. Simple uterus (Human & primates) has a pear-shaped body with no uterine horns.
  12. 12. Basic types of uteri found in mammals
  13. 13.  The cervix is the sphincter-like segment of the reproductive tract which separates uterus from vagina.  The function of the cervix is to close the uterine lumen against macroscopic and microscopic intruders (except during estrus and parturition)  At estrus, the cervix serves as a passageway for sperm.  In pregnancy, the cervical mucus hardens and seals off the canal by forming the "cervical plug" or "cervical seal" which liquefies/softens shortly before parturition.  At parturition the cervix dilates allowing passage of the fetus and fetal membranes. 4: The cervix
  14. 14. 5: Vagina  The vagina is tubular in shape, thin-walled and quite elastic.  The vagina is the female organ of copulation and acts as birth canal.  In the cow, doe and ewe, semen is deposited into the anterior end of the vagina near the opening to the cervix, during natural mating. 6: Vulva  The external opening of the female genitalia.  Two parts: 1.Clitoris, structure of erectile tissue (homologous with the male penis) 2.Vestibule, portion of the female duct system that is common to both the reproductive and urinary systems
  15. 15. B: REPRODUCTIVE SYSTEM OF MALE ANIMAL • Male reproductive organs are divided into two: • Primary organ Testis (Testicle) Production of gametes Production of reproductive hormones • Secondary organs Ducts, Accessory glands and Penis Transportation Nutrient production Deposition of semen / copulation
  16. 16. 1: Testis • Testis (plural, Testes) is primary organ producing spermatozoa and sex hormones (androgens). • Testes descend from their site of origin, near the kidneys, down through the inguinal ring into the scrotum. • In some cases one or both testes fail to descend due to a defect in development. • If both fail, the animal is bilateral cryptorchid, if one testis descends he is a unilateral cryptorchid.
  17. 17. • Testes are covered with tunica vaginalis, a serous tissue, which is an extension of the peritoneum. • The outer layer of the testes tunica albuginea. • Tunica albuginea extends through the parenchyma (The functional layer of testes) of the testis and divide it into lobules. • Each lobule is composed of several seminiferous tubules and the surrounding connective tissue. • Spermatogenesis (formation of spermatozoa) occurs in the epithelial lining of the seminiferous tubules. • Several seminiferous tubules are found in each lobule
  18. 18. • Seminiferous tubules contain germ cells (spermatogonia) and nurse cells (Sertoli cells). • Scattered throughout the loose connective tissue surrounding the seminiferous tubules are interstitial cells (Leydig cell), that produce testosterone • Seminiferous tubules join a network of tubules, the rete testis, which connects to 12 to 15 small ducts, the vasa efferentia which, converge into the head of the epididymis.
  19. 19. 2. Scrotums and Spermatic Cord • The scrotum is two-lobed sac, which enclosed the testes. • It is located in the inguinal region between the rear legs of most species. • It is composed of an outer layer of think skin with numerous large sweat and sebaceous glands. • The inner lining is formed by a smooth muscle fibers, the tunica dartos dividing the scrotum into two pouches.
  20. 20. • The spermatic cord connects the testis to the convoluted testicular arteries and surrounding Venus plexus, and nerve trunks. • The spermatic cord is composed of smooth muscle fibers, connective tissue, and a portion of the vas deferens. • Both the spermatic cords and scrotum contribute to the support of the testes. Also, they have a joint function in regulating the temperature of the testes.
  21. 21. 3. Epididymis • Epididymis is the first external duct leading from the testis. • The epididymis has three major parts: the caput (head), corpus (body) and Caudal (tail) • Functions of epididymis: a) Transportation of spermatozoa b) Concentration of spermatozoa c) Storage of spermatozoa d) Maturation of spermatozoa
  22. 22. 4. Vas Deferens and Urethra • Vas deferens: pair of ducts with one leading from the distal end of the caudal/tail of each epididymis. • Vas deferens: has a thick layer of smooth muscles with a major function of transportation of spermatozoa. • Urethra: is a single duct, which extends from the ampullae (enlarged part of vas deferens) to the end of the penis. • Urethra serves as an excretory duct for both urine and semen.
  23. 23. 5. Accessory Glands • Including: vesicular glands, prostate gland and bulbourethral / Cowper's glands . a) Vesicular glands (seminal vesicles) Pair of lobular glands with knobby appearance "cluster of grapes“ function by secretion of Phosphate and carbonates which buffer / protect semen against pH shift/change.
  24. 24. b) Prostate gland: • Single gland located around and along the urethra. • The prostate secretions are high in inorganic ions of sodium, chlorine, calcium & magnesium. c) Bulbourethral (Cowpers) glands: • Paired glands located along the urethra. • Secretes fluids which flush urine residue from the urethra before ejaculation.
  25. 25. 6. Penis • The penis is the organ of copulation in males. • It starts from the point where the urethra leaves the pelvis up to free end with the external urethral orifice. • Bulls, boars, and rams have a sigmoid flexure, (S-shaped bend in the penis), which with aid of retractor penis muscles permits penis to be retracted completely into the body. • In most species the penis is fibroelastic, containing small amounts of erectile tissue.
  26. 26. 7. Prepuce • The prepuce (sheath) is an invagination of skin, which completely enclosed the free end of the penis. • It can be divided into a prepenile portion, which is the outer fold, and the penile portion, or inner folds. • The orifice of the prepuce is surrounded by long and tough preputial hairs.
  27. 27. Reproductive Hormones  Hormones are organic substances secreted by certain specialized cells (glands) in the body, which diffuse or transported to some other part of the body and bring about certain changes.  A number of hormones are directly or indirectly involved in various aspects of reproduction.  The secretion of these hormones is essential for the maintenance of a proper internal environment to ensure successful reproduction.
  28. 28. Major hormones involved in reproduction of female animals Endocrine gland Hormone Function Anterior Pituitary 1. Follicle Stimulating Hormone (FSH) Stimulates growth and development of the follicles in the ovary 2. Luteinizing Hormone (LH) Causes mature follicles to rupture. The ruptured follicle becomes the corpus luteum 3. Prolactin Maintains lactation
  29. 29. Endocrine gland Hormone Function Posterior Pituitary Oxytocin 1. Stimulates the letdown of milk. 2. Stimulates muscular contraction of the uterus at birth. Ovaries 1. Oestrogen 1. Stimulation of oestrus or heat so that the female will accept the male. 2. Promotes growth of the uterus and mammary glands. 2. Progesterone (Secreted by corpus luteum) 1. Maintains pregnancy and stimulates the development of the wall of the uterus. 2. Prevents oestrus and ovulation by inhibiting FSH production. 3. Relaxin 1. Causes pelvic ligaments to
  30. 30. Source Hormone Function Testes Testosterone (From Leydig cells) 1.Regulates spermatogenesis. 2.Controls the development of secondary sex characteristics and for normal mating behavior. 3.Necessary for the function of the accessory glands and male duct system. Anterior Pituitary 1. LH Necessary for the development of the Leydig cells. 2. FSH Stimulates development of Sertoli cells Major hormones involved in reproduction of Male animals
  31. 31. Other animal reproductive hormones: 1. Gonadotropin Releasing Hormone (GnRH), secreted by Hypothalamus, causes ovulation of the dominant follicle by causing the release of the luteinizing hormone from the pituitary gland. 2. Prostaglandin (PGF2α), secreted by the uterus, causes regression of the CL and a decrease in progesterone levels. If the cow is pregnant, the embryo will block the release of PGF2α and allow the CL to continue to secrete progesterone. 3. Progesterone, secreted by the corpus luteum. a) suppresses further development of follicles and the secretion of estrogen. b) Necessary for preparing the uterus to receive the fertilized egg. c) Maintains proper uterine environment for continuation of pregnancy.
  32. 32. Clinical Use of Reproductive Hormones 1. Gonadotropin Releasing Hormones (GnRH): a) Used in the treatment of ovarian follicular cysts, b) Induction of ovulation c) Oestrus synchronization. 2. Oxytocin a) Induces milk let-down in heifers and in cows with subnormal milk production. b) Hastens uterine involution following dystocia, caesarean operation, replacement of uterine prolapse, uterine trauma or hemorrhage.
  33. 33. 3. Progesterone (Progestogens/Progestins)  Sectreted by the corpus luteum (main source), placenta (especially of the ewe and mare after the first 1/3 and 1/2 of gestation respectively). a) Prevent abortion due to an actual or possible progesterone deficiency. b) Synchronization of estrus in the mare, ewe, cow and sow c) In heifers are used to promote growth - suppresses heat 4.Prostaglandins (prostaglandin F2 Alpha (PGF2α). 1. Evacuation of the uterus (mummified, pyometra, endometritis). 2. Synchronization of estrus. 3. Induce abortion in heifers and ewes (mated too young). 4. induction of early parturition in cows (cases of fetal oversize). 5-Treatment of luteal cysts
  34. 34. 5. Pregnant mare serum gonadotropin(PMSG) (Now: equine chorionic gonadotropin - eCG).  Produced by the endometrial cups of the mare from about 40 to 140 days of pregnancy. It contains both FSH and LH, but its activity is mainly FSH. 1. Superovulation of donor cows for embryo transfer. 1. Used to control ovulation in female and treating persistence infertility, 2. Treat cryptochidism in males. LH increases testosterone production, which cause descent of the testicles into the scrotum. 6. Human chorionic gonadotropin (hCG)  Secreted by chorionic epithelial cells of human placenta, excreted in the urine and reaching a peak levels at about 50 days of pregnancy.  Its activity is predominantly LH.
  35. 35. OESTROUS CYCLE IN DOMESTIC ANIMALS. DEFINITIONS Estrous cycle: period of reproductive cyclicity / physiologic functional regularity of the reproductive system. Anestrus: periods of no estrous cycles (occurs during pregnancy, nursing, season of year, poor nutrition, pathological conditions). Estrus: is a Noun, the period of sexual receptivity (Syn: Heat). Seasonal Breeders: animals that have one or more estrous cycles during certain periods of the year.
  36. 36. Polyestrous Animals: animals with estrous cycles throughout the year e.g., cattle, Pigs, Humans. Sometimes only bred at certain periods of the year, but will cycle all year. Seasonally Polyestrous Animals: animals that have multiple estrous cycles only during certain periods of the year. Monestrous animals: animals that have one estrous cycle per year e.g. Dogs, wolves, foxes, and bears
  37. 37. THE OESTROUS CYCLE.  Oestrous cycle occurs in all animals reached puberty.  The cycle is divided into 4 or 5 well-marked period or phases, each of these periods merges into each other. 1. Proestrus. 2. Estrus. 3. Metestrus. 4. Diestrus. 5. Anaestrus.
  38. 38. Length of Estrous Cycle in Different Animals Animal species Length (Range) 1. Ewe 17 days (13 - 19) 2. Goat 21 days (15 - 24) 3. Sow 21 days (17 - 25) 4. Cow 21 days (17 - 24) 5. Mare 21 days (15 - 25) Animal spp. Estrus Metestrus Diestrus Proestrus 1.Cow 12-18 hrs 6-8 days 9 days 3days 2.Mare 4-7 days 5-6 days 5-9 days 3days 3.Sow 2-4 days 5-7 days 7-11 days 3days 4.Bitch 9 days 60-90 days 45-90 days 9days. Length of phases of estrous cycle in domestic animals
  39. 39. 1. Proestrus.  The period of development of the Graafian follicle, under the influence of FSH.  At this time, there is increase in the production of Oestrogen. 2. Estrus.  The period characterized by sexual desire and the acceptance of male by the female animal.  The Graafian follicle is large and mature, the ovum undergo maturation changes.  Oestrogen produced during this phase is high leading to genital tract changes.  Ovulation occurs towards the end of this period of oestrus (in most animals)
  40. 40. 3. Metestrus.  Is the period which follows estrous X2 by rapid development of corpus luteum from the ruptured follicle.  The period under the influence of the progesterone, Progesterone inhibits FSH secretion, to prevent development of graafian follicle. 4. Diestrus.  Is a longest period in oestrus cycle X2 by the presence of matured corpus leteum in a non-pregnant animal.  Also is called the resting period, because the genital tract is in a quiescent state.  At the late stage of this period, there is regression of the corpus leteum, which gives chance for development of primary and secondary follicles and finally proestrus occur.
  41. 41. 5. Anaestrus.  It occurs in non-polyestrous animals X2 by functionless of ovaries and the reproductive tract.  Anaestrus is normally followed by the proestrus.  This phase is observed physiologically in mare, ewe, bitch and cat.  In these animals, diestrus is short (1week) but anaestrus takes several months.  During anestrus, the uterus is small and flaccid and the vagina mucus is scanty and sticky.
  42. 42. SIGNS OF ESTRUS (HEAT). Behavior and physiological changes occurring during estrus in domestic animals, particularly in a cow: 1. Mounting other animals and accept to be mounted. 2. Excessive bellowing / Grunting. 3. Restlessness and loss of appetite. 4. Increase mucus secretion in the cervix and vagina, lead to clear string of mucus extruded from the vagina and often adhere to the tail. 5. Slightly drop of milk production in daily animals. 6. Lips of the vulva become swollen, enlarged and deeper red in colour compared with non-estrus animal.
  43. 43. Animal Length of estrus Time of ovulation 1. Mare 4-7 days 1-2 days before the end of oestrus. 2. Cow 12-18 hrs 12-14 hrs after the end of oestrus. 3. Ewe 24 to 36 hrs 12- 24 hrs before the end of oestrus. 4. Goat 24 - 40 hrs About the last day of oestrus 5. Sow 2-4 days 30-36 hrs after the onset of oestrus 6. Dog 9 days 1-2days after the onset of oestrus TIME OF OVULATION IN DOMESTIC ANIMALS.
  44. 44. Animal Av. Length of oestrus cycle Time of ovulation Optimum time for service. Mare 21 days 1-2 days before end of oestrus. 3-4 days before the end of oestrus Cow 21 days 12-14 hours after the end of oestrus. Just before the middle of oestrus to the end of oestrus. Ewe 17 days 12- 24 hours before the end of oestrus. 18-24 hours after the onset of oestrus. Goat 21 days About the last day of oestrus 24-36hours after the onset of oestrus. Sow 21 days 30-36 hours after the onset of oestrus 12- 30 hours after the onset of oestrus Dog 2 cycles per year One to two days after the onset of true oestrus 2-3 days after the onset of true oestrus Cat 21 days 24-30 hours after coitus Difficult to practice. CORRECT PERIOD OF SERVICE IN DOMESTIC ANIMALS
  45. 45. FERTILIZATION. Definition: The fusion of male and female gamete to form a Zygote. STAGES OF FERTILIZATION 1. Gamete maturation.  Before fertilization (in the ampulla- isthmus junction), two events in the gametes have to occur: a)Spermatozoa have to undergo a series of maturation in the female genital tract (Capacitation) - final maturation of spermatozoa which involves the removal of the head cover (acrosomal cap) of the spermatozoa. b)Ovum must complete its first meiosis Phase before or after ovulation.
  46. 46. 2. Penetration of sperm to the ovum.  Once the sperm is contact to the ovum, it release two hydrolytic enzymes; Acrosin and Hyalulonidase. a) Hyalulonidase enzyme cause a break down of the cellular component around the oocyte (zona pellucida), b) Acrosin digest the acellular protein around the oocyte.  The enzymatic digestion is called Acrosomal reaction.
  47. 47. 3. Sperm attachment.  Spermatozoa have Receptors for attachment to the ovum called ZP sperm receptors  Only spermatozoa with good morphology (intact sperm) can be able to lock at this receptor. 4. Gamete fusion.  The nucleus of the sperm and the egg eventually combine to form a diploid zygote and fertilization is completed  The egg’s membrane quickly prevents additional sperm from entering the egg by: a) Depolarization of ovum (fast block to polyspermy) b) the cortical reaction causes a hardening of the zonapellucida
  48. 48. DEVELOPMENT OF CONCEPTUS (GESTATION)  Gestation is the time period from fertilization (conception) to parturition or birth of the young.  During this period, single cell divide and develop into highly organized individual.  The period of gestation can be divided into 3 stages. 1. The period of embryo. 2. The period of embryo and organogenesis. 3. The period of fetus and fetal development.
  49. 49. 1. THE PERIOD OF EMBRYO. a) This is the period from fertilization to about 10-12 days, when the primitive fetal membranes are formed in the uterus. b) The fertilized ovum is divided mitotically (process known as Cleavage) immediately after fertilization is complete. c) The zygote (one large cell) divides into several smaller cells called blastomeres @ has its own nucleus. d) The first five to seven divisions result in the Morula, a simple ball of blastomeres cells. e) Due to contraction of the uterine wall, the ovum moves from the oviduct to the uterus.
  50. 50. f) A fluid-filled cavity forms within the Morula, the cavity is called the Blastocoel. g) The Morula becomes a Blastula when the blastocoel is fully formed. f) After the few cell divisions (cleavage), there is a dramatic rearrangement of cells of the blastula to form a three-layered embryo with a primitive gut. 2.THE PERIOD OF EMBRYO AND ORGANOGENESIS. a) This extends from day 12 to about one to two months depend on the animal species. b) During this period major tissue organ and systems of the body are formed.
  51. 51. c) At the end of this period you can identify the species of the embryo. d) Three germ layers arise from the inner cell mass of the Blastula: ectoderm, mesoderm & endoderm. 1. Ectoderm, the most external layer, forms the skin, hair, hooves and mammary glands, brain and the nervous system. 2. Mesoderm, the middle germ layer, forms muscle, the skeletal system, and the circulatory system. 3. Endoderm, the most exterior germ layer, forms the lining of the gut and other internal organs h) At this stage most severe developmental defect/anomalies do occur, and the embryo can die, get expelled out or absorbed.
  52. 52. Germ Layer Organs Ectoderm 1. Central nervous system 2. Sense organs 3. Mammary glands 4. Sweat glands 5. Skin 6. Hair 7. Hooves Mesoderm 1. Circulatory system 2. Skeletal system 3. Muscle 4. Reproductive systems (male and female) 5. Kidney 6. Urinary ducts Endoderm 1. Digestive system 2. Liver 3. Lungs 4. Pancreas 5. Thyroid gland 6. Primordial germ cells
  53. 53. 3. THE PERIOD OF FETUS AND FETAL DEVELOPMENT. a) This stage starts where the second stage ends (35 days in small ruminants, 45-60days in cow, 55 days in horses) and end at parturition. b) Minor details in differentiation of organs and tissues do occur. c) Also growth and maturation of antenatal individual occurs including rapid increase of fetal size especially in the last 2-3 months of gestation. d) In ruminants cotyledons and caruncles develops and become enlarged to supply nutrients to the fetus.
  54. 54. Types of placenta: 1. Placenta diffusa: found in swine and horses 2. Placenta cotyledonaria: found in ruminants 3. Placenat zonaria (anularis): found in canivores 4. Placenra discoidalis: found in humans, rodents and primates
  55. 55. PREGNANCY DIAGNOSIS (PD) Indicators of pregnant animals. 1. External indication. a) History mostly used for indoor animal keepers, where the animal owners keep records of animal oestrus cycles and services. b) Behaviour changes include the increase in the body weight especially in advanced pregnancy where the cow become quiet and moves slowly.  The main objective of pregnancy diagnosis is to be able to detect those animals, which are not pregnant, so that the animal can be rebred.
  56. 56. c) Anatomical changes includes a marked sinking of gluteal muscles, oedema of the vulva and relaxation of the vulva(identifiable in the last two weeks of pregnancy). d) Morphological changes, the increase of the abdominal size, the udder (heifer at 4-5 months of pregnancy begin to increase in size), Enlargement and oedema of the udder, the lactating cow begins to decrease milk production, the last week of pregnancy. 2. Internal indications.  Animal internal reproductive organs.  Hormonal changes
  57. 57. Several methods are available to determine if a cow or heifer is pregnant. 1. History of non-return to estrus 2. Rectal examination (palpation) 3. Hormonal measurements 4. Radiograph/Ultrasound examination 5. Abdominal palpation/Vaginal examination
  58. 58. 1. Non-return to oestrus  If oestrus signs are not observed around 3 weeks after service or insemination, the cow is generally assumed to be pregnant.  However, even if oestrus detection is good, not all of these cows will be pregnant.  On the other hand, up to 7% of pregnant cows will show some signs of oestrus during pregnancy.  Insemination of these animals may result in embryonic or fetal death.
  59. 59. 2. Rectal palpation  Based on the uterine changes during pregnancy that can be detected by rectal palpation.  The method is used to detect the size of the uterus and the corpus luteum in the ovaries.  Advantage: immediate result enabling early treatment of non-pregnant cattle.  Accuracy: depends on the experience of the practitioner and can reach 95%.  Rectal examination is usually carried done between 35 and 65 days post AI.
  60. 60. Indicators: a) Enlargement of horn (30-40 days of gestation). b) Palpation of amniotic vesicle in early pregnant ( 40-50 days of gestation). c) Slipping away of fetal membrane following gentle pinching (40-90 days of gestation). d) Palpation of placentoms (3.5-4 months). Placentomes are the structures formed by the union of maternal caruncles and fetal cotyledons by which the placenta is attached to the uterus. e) Palpation of fetus (3- 9 months of gestation). f) Palpation of enlarged middle uterine artery (120-150 days of gestation), this is accompanied by the characteristics changes by the pulse (of the blood) in this artery, and changes are called Fremitus.
  61. 61. Stage of pregnancy (days of gestation) Uterine position Uterine diameter Palpable Structures 35-40 Pelvic floor Slightly enlarged Uterine asymmetry/fetal slip 45-50 Pelvic floor 5.0 - 6.5 cm Uterine asymmetry/fetal slip 60 Pelvis/abdomen 6.5 - 7.0 cm Membrane slip 90 Abdomen 8.0 - 10.0 cm Small placentomes/fetus (10-15 cm long) 120 Abdomen 12 cm Placentomes/fetus (25- 30 com long)/fremitis 150 Abdomen 18 cm Placentomes/fetus (35- 40 cm long)/fremitus
  62. 62. 3.Hormone measurements a) Progesterone assay  The progesterone secreted by a functional corpus luteum between 18 and 24 days after service or insemination is an early indication of pregnancy.  It can be assayed in milk or plasma.  Optimal assay time is 24 days after service or AI, this eliminates the possibility of long oestrus intervals which might result in false positives. b) Early Pregnancy-associated Proteins  Commonly used are early conception factor (ECF) or pregnancy-associated glycoprotein in blood samples.  Detect the pregnancy-associated glycoprotein within 48 hours of conception.  Because of the high incidence of embryonic mortality, Pregnancy should be confirmed later by rectal or ultrasound examination.
  63. 63. 4. Ultrasound examination  Real time (B-mode) ultrasound is a reliable and relatively simple method of diagnosing pregnancy as early as day 26.  An accuracy of over 99% can be achieved, enabling fertility problems to be identified rapidly.  The main disadvantages of the use of ultrasonography are related to cost and time involved (Ultrasound machines are expensive and it takes more time to perform a pregnancy diagnosis with an ultrasound machine than by rectal palpation)
  64. 64. 5. Abdominal palpation/Vaginal examination  Common in bitch and queen for diagnose pregnancy.  Because the uterus becomes uniformly enlarged, pregnancy is more difficult to determine by palpation.  An abnormal condition (pyometra, mucometra, torsion) may develop that can also cause the uterus to be enlarged. Such a condition would need to be distinguished from a pregnant uterus.  Vaginal cytology is a simple technique that can be used to characterize stages of the reproductive cycle of the bitch or to evaluate certain diseases of the genital tract.

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