The process of formation and development of ova
Ova differentiation occurs in the phase 2 stage of mitosis and meiosis stage:
Mitosis (multiplication): Oogania proliferate from germ cells (Primordia) produced several generations of identical cells. Oogonia entered prophase of meiotic division I as a primary oocyte. Primary oocyte stops at prophase until adult sex occurs. I meiotic division results in a change to the primary oocyte secondary oocyte. Generally occurs before ovulation, except in horses and dogs secondary oocyte formation occurs after ovulation. At the time of ovulation oocit metaphase II stage of meiosis II. Meiotic division II continues when the spermatozoon through the zona pellucida and activate the secondary oocyte (Anon, 2009).
Ovulation
Ovulation is the release of an ovum from the ovary cells as a result of follicular rupture that has been cooked. The time needed by the whole process of ovulation depends on the location of eggs in the follicles. A short time when ovulation will the egg cell at the bottom of the follicle and will be long when the egg is near the stigma surface protruding ovaries (Anon, 2009).
Mechanism of ovulation:
a. Hormonal:
After the follicles to grow because of the hormones FSH from the anterior pituitary, the follicle cells are capable of producing sexual estrogen and progesterone. Both these hormones in small doses will cause the release of the hormone LH. LH hormone plays an important role in ovulation bluffing. Rupture of follicles occurred in the pressure of growing follicles and persobekan the stigma pale area because this area lacks the blood.
b. Neural:
Stimulation on the outer cervix, either during copulation or artificial mating will be forwarded by the nerves to the central nervous system which will be received by the hypothalamus. Will be realising hormone secreted LH and LH levels in the blood will increase, which causes ovulation (Anon, 2009).
From the remnants of follicles that had undergone ovulation will form a variety of fabrics are:
1. Corpus haemoragikum
After ovulation will be followed by providing more blood to the remnants of follicles. Hiperplasi occurred in hipertropi and weaving so tebentuk round objects protruding surface of the ovary, resilient, and red
2. Corpus luteum
As a result of the process of the corpus luteinasi by the influence of hormones haemoragikum LTH, there was further growth of these cells. New Tenenuan will change color to yellow and produces progesterone for long to be high at the peak of the cycle of sex.
3.Korpus Albikansia
Cessation of activity in the corpus luteum produces progesterone will cause degeneration of cells that had not obtained the shape of the blood supply becomes very small and pale. Ovulation in cows occurs about 10-12 hours after estrus ended. A disturbance at the time of ovulation does not occur can lead to fertilization and embryo development or disturbance. Ovulation disorders may occur due to deficiency or imbalance of the endocrine and mechanical factors (Anon, 2009).
Fertilization
Meeting / union of sperm cells with egg cells is called fertilization or fertilization. In normal circumstances in vivo, fertilization occurs in the area generally in the fallopian tube ampulla region / infundibulum. Spermatozoa to move rapidly from the vagina into the uterus, into the tube. This movement may be influenced also by the role of myometrial contraction and the wall of the tube which also occur during intercourse (Yosemite, 2009).
Then spermatozoa had events:
1. capacitation reaction: for a few hours, plasma proteins and glycoproteins that are in diluruhkan semen.
2. akrosom reaction: after close to the oocyte, sperm cells that have undergone capacitation will be affected by substances corona radiata of the ovum, so that the contents of the head area akrosom sperm are released and exposed to the corona radiata layer. At this time released hyaluronidase can dissolve the corona radiata, trypsine-like agent and lysine-zone that can dissolve and help the sperm through the zona pellucida to reach the ovum.
Once a sperm zona pellucida touch, there is a strong attachment and penetration is very rapid. Once a breach has occurred by a single sperm zones, a special reaction in the zone pellucida (zone-reaction) which aims to prevent the occurrence of sperm penetration by other again (Yosemite, 2009).
The main results of fertilization
1. fulfillment of returning the number of chromosomes from the merger of two haploid paternal half
and the mother would be a new individual with a diploid chromosome number.
2. determining the sex of the new individual will depend on the X or Y chromosome that
contained sperm fertilize the ovum.
3. cleavage and the beginning stages of the embryo formation and development of
(embryogenesis) (Yosemite, 2009).
Implantation
At the end of the first week (day-to-5 to 7) zygote reaches cavum uteri. At that time the uterus is in the mucus secretion phase under the influence of progesterone from the corpus luteum is still active. So that the endometrium lining the uterine wall into the blood vessel-rich estuaries and many uterine mucous membrane glands open and active. Contacts between the zygote stage to blastocyst in the uterine wall that state would trigger various cellular reactions, so that cells can trofobas zygote and held against infiltration of the endometrial epithelial lining of the uterus (implantation occurs). After implantation, trophoblast cells are embedded in the endometrium continues to grow, forming a network along with the maternal vascular system to be PLACENTA, which then serves as a resource for nutrition and oxygenation embrioblas network that will grow into a fetus (Yosemite, 2009).
Embryogenesis
Zygote started early mitotic division until a couple of times. Cells generated from each division are smaller than the size of its parent, called a blastomere. After cleavage of 3-4 times: 16 levels of the zygote enters the cell, called Morula stage (approximately on day-to-3 until 4 pascafertilisasi). Morula consisting of inner cell mass (a collection of cells on the inside, which will grow into the tissues of the embryo to fetus) and the outer cell mass (cell layer on the outside, who would grow up to placental trophoblast). At about the day-to-5 to 6, in the cavity between the inner cell mass of fluid seeps through the zona pellucida, forming a space between cells. Space between these cells and then come together and meet most of the mass of the blastocyst cavity form a zygote. Inner cell mass remained gathered at one side, still bordered by outer cell layer. At this stage in the zygote stage called blastula or blastocyst formation. Inner cell mass later called embrioblas, and then the outer cell mass called the trophoblast (Yosemite, 2009).
Birth
Parturisi is a birth process. Here the fetus is responsible for the initiation of birth, endocrine processes quite different from one species to another, in some species these processes can not be explained in detail. Increased fetal cortisol production occurs as a result of the change and maturity action hypothalamic-pituitary-adrenal fetus. It is estimated that the stress caused by the growing fetus because the placenta is no longer able to supply the needs and demands of fetal growth (Hary, 2009).
The incident that preceded the birth of endocrine, among others;
• Increased production of corticotropin-releasing hormone (CRH) by the fetal brain.
• Peningakatan production hormonr adenocrticotropic (ACTH) by the fetal anterior pituitary gland.
• Increased production of cortisol by the fetus galndula adrtenal
• Perubahamn placenta to estrogen progerteron
• Estrogen menstimuli myometrium to produce prostlagladin F2a (PGF2a) and also causes relaxation of the cervix
• PGF2a causes contraction of the myometrium will cause press uterin and intra memndorong toward cervic fetus.
• Oxytocin galandula be issued by the posterior pituitary and fetal stem spur cervic dilatation.
• Oksitocin menyebabakn kontrakasi myometrium.
Peptide hormone relaxin is produced by the placenta or the maternal corpus luteum in early kebuntingan. Relaxin also play a role in the relaxation of the maternal cervix before birth and affects the efficiency of contraction of myometrium (Hary, 2009).
Antenatal
The signs can be observed close to the birth during the end of the month kebuntingan, these signs include:
• Rotation of birth position
During kebuntingan, the fetus will fall down on your back with legs facing up. After rotation to the position of birth, the fetus will fall down on the thorax or abdomen with the front legs to be positioned at the end of the cornua near the cervix and nose located between the front legs. With this position, the birth easier.
• Changes gl.mammae
Gl.mammae growth can be seen during the late kebuntingan. This is caused by joint estrogen and progesterone stimulate the development of ducts and tissues gld.mammae secretion. Approaching the birth gl.mammae be enlarged and filled with milk. Milk synthesis is a function of prolactin in collaboration with other hormones. When oxytocin is released during birth, there was milk let down, causing the milk out of nipples (Hary, 2009).
• Other Changes
Closer to the birth of the Relaxin in cooperation with estrogen will cause relaxation of the pelvic ligaments and cervix channel expansion. Lig pelvic relaxation around the base of the tail will cause the base of the tail is more prominent. Vulva are tender and swollen. Mucus look like when leleran of the vulva sel2 estrogen causes the cervix secrete mucus epithel new, so dilute mucus plugs. Sheep will try to leave the group. Sheep will find a place to hide during the birth (Hary, 2009).
Stages of birth:
The first stage of birth:
Dipercya this stage lasts 6-12 hours. Ewe will separate themselves from the group and look gelidah and scratching the ground. Some of the ewe does not show any sign of the first stage of birth.
The second stage of birth:
This phase lasted ½ -1 hour and maybe a little longer on the new ewe gave birth the first time. The majority of lambs entering the canal on the anterior longitudinal presentation dengfan same posture like a calf. Some lambs were born with a presentation posteriore with rear legs that protrude into the canal. Little lamb in the anterior presentation can sometimes be born with one foot in front of shoulder flexion. Normally the female will lay the sheep to give birth, with a strong push and lifted his head up and bellows. Many choose ewe lying back position. Against the wall or fence for the second melahirkan.tahap repeated during the next lamb born. Approximately 50% of children born with amniotic sheep intact (Hary, 2009).
The third stage of birth:
The placenta is normally off within 3-4 hours after acquisition last lamb.
BIRTH PROCESS
Initiation of hormone:
Hormonal patterns during the final stages of birth kebuntingan set. Levels of estrogen, progesterone, and relaxin highly visible so that it can be seen that the mechanism that initiates the release of birth by fetal cortisol. The increase in cortisol production and release caused a greater than estrogen by the placenta that initiate the release of PGF2a from uterusPGF2a that cause CL regression and a drop in progesterone. The placenta is the main source of progesterone in sheep during the 2 / 5 final kebuntingan (Hary, 2009).
Apparently an increase in fetal cortisol causes a change in the placental enzyme which produces progesterone to estrogen conversion. Placental estrogen causes the release of PGF2a from the uterus of sheep but a decrease of progesterone seen before PGF2a increases.
Oxytocin apart when fetal movement sensory nerve merangang cervix and vagina. The highest oxytocin Konsenjtrasi seen during fetal expenses. Small spike seen during the release of placental expenditures greater PGF2a caused by oxytocin. An increase in antenatal parent cortisol may be caused by stress parturisi and not involved in the regulation parturisi. Prolactin surge associated with the synthesis of milk and not with parturisi.
The main physiological occurrence in parturisi:
Dilatation of the cervix to track fetal
Initiation of cervix dilatation caused by relaxin in collaboration with estrogen increases. Cooperation these hormones soften the cervix and cause epithelnya cells secrete mucus. Subsequent dilation occurs when the uterine contractions push allanto-chorion and amnion kemdian toward the cervix. Allanto-chorion may be broken during this process. Amnion usually not broken until the fetus into the cervix (Hary, 2009).
A number of factors involved in initiation and continuation of uterine contractions that occur simultaneously with the dilatation of the cervix and then continued for several hours after spending the fetus.
Progerteron depression, then wrote increased estrogen resistance caused by the loss of myometrium contraction teerhadap and make it more active on the nature agenagen stimulating. Effuse uterine contractions and fetal placenta (Hary, 2009).
Initial contraction of the uterus may be caused by PGF2a when released from the endometrium with an increase in estrogen. This initial contraction is weak, irregular, occurs kira2 with 15-minute intervals when the fetus driven into the cervix sensory nerve impulses cause the release of posterior pituitary oxytoxin.
The increased release of oxytocin was accompanied by the release of a larger PGF2a. Oxytoxin acts directly on the myometrium, or indirectly through the stimulation of the release of PGF2a larger, causing uterine contractions will be stronger, more rhythmic and more frekuen PGF2a and Oxytoxin peaked during the release of fetal
Mortality Fetal anoxia caused by other factors which may cause strong contractions labih end-stage approach when the fetus removed. When the uterus to contract causing reduced blood flow to the fetus, the oxygen supply running low, which causes increased activity associated with anoxia. Mechanical movement of the fetus which lead to uterine contractions cause stronger contractions.
A moment fetus seblum expenses, uetrus contractions became regular, strong and frekuen, which happened kira2 with 2-minute intervals that lasted for 1 minute kira2. Contraction of abdominal muscles will help end the fetus expenses.
After spending decreased fetal uterine contractions. This reduction will menlanjut for 1-2 days. Yg continuous contraction is responsible for expenses or liquid membranes and placental fragments of placental tissue is left in the uterus. Oxytosin second spike expenses associated with the placenta (Murti, 2009).
Disruption of ovulation may be delayed ovulation, anovulation and folikuler sista.
Delayed ovulation (Delayed ovulation)
Delayed ovulation is one of the causes of infertility. This incident can menyebebkan IB marriage or not on time so that fertilization does not occur and eventually failure kebuntingan. The cause of ovulation could be delayed due to low levels of LH in the blood or because diperpanjangnya period folikuler. The diagnosis can be done is folikelnya PR 24-36 hours after estrus ended. Symptoms that appear in this case is the occurrence of repeated mating. Therapy can be done with injesi GnRH (Gonadorelin microgram 100-250) when the IB or the provision of hCG (Admin, 2008).
Sista Ovaria
Cystic say when Ovaria contains one or more structures that contain fluid and larger than the mature follicle. The existence of these sista cause follicular de graf do not ovulate (anovulation), but experienced regression and atresia or experience that luteinisasi follicle size increases, the granulosa cell layer degeneration and memetap at least 10 days (Admin, 2008).
As a result the cows became anestrus or nimfomania. Ovaria sista is one of the causes of infertility. Predeposisinya factor is hereditary and diet. Cause sista is ovaria ovulation and endocrine disorders. Treatment can be with the LH / hCG, GnRH, PGF2α (Admin, 2008).
Based on the events are divided into ovaria sista sista folikuler, sista sista korpora luteal and luteal.
A. Sista folikuler
Is the set of follicle does not ovulate due to low hormone LH. Number sista be one or more on one or both ovaries. Symptoms folikuler sista is continuous estrus (nimfomania) if sistanya much or anestrus if sistanya bit and anovulotorik nature. If the event becomes chronic nimfomania usually causes sterility hump. On per rectal examination of the ovaries will be felt smooth surface, diameter> 2.5 cm, thin walls and if there is pressure fluctuations. Treatment can be done by granting enukleasi and hormone LH or HCG (Admin, 2008).
B. Sista luteal
Formed because the follicle has luteinisasi result in a sudden increase in LTH. Genesis sista luteal ovary is usually single and often occurs in the production of dairy cows high. Symptoms luteal sista is not showing estrus (anestrus) and its anvulatorik (inability to ovulate). On per rectal examination of the ovaries palpable diameter> 2.5 cm, the surface of the ovary and luteal clear boundary, the walls thick and feels springy when pressed. Treatment with PGF2α or giving way to the sista enukleasi luteal (Admin, 2008).
C. Korpora sista luteal
Sista is formed from follicles which had ovulated and then had some luteinisasi so there is the center of the hollow and filled with fluid., Usually single on one ovary. Basically, this condition have a normal cycle, estrus and ovulation and fertilization can occur but the condition can not be maintained conception because of low progesterone in the blood. Manifesti of luteal korpora sista characterized by repeated mating. On per rectal ovarian palpation palpable rubbery when pressed, he ether of> 2.5 cm and thick-walled. Treatment with PGF2α if it does not happen kebuntingan (Admin, 2008).
Anovulation
Often associated with true anestrus, but estrus can occur but the follicle regresses or atresia. Also often occurs in cows after partus, where there is a marked ovarian activity by the estrous but not weak because the follicle is growing at a maximum, and lost (anestrus) because the follicle regresses. Not until the ripe follicle development and ovulation is not possible due to low levels of FSH and LH hormone. Sometimes the follicle does not reach the size of regression and 2-2,5 cm, but the walls that have similar luteinisasi corpus luteum or follicles develop into follicular de graf but fail to ovulate due to hormone disorders gonadotropin release. Clinical symptoms in this case the estrus again after marriage or the marriage over and over. On per rectal examination of the ovaries palpated rounded or smooth, no fluctuations, solid as the corpus luteum. Therapy using HCG or GnRH (Admin, 2008).
Ova differentiation occurs in the phase 2 stage of mitosis and meiosis stage:
Mitosis (multiplication): Oogania proliferate from germ cells (Primordia) produced several generations of identical cells. Oogonia entered prophase of meiotic division I as a primary oocyte. Primary oocyte stops at prophase until adult sex occurs. I meiotic division results in a change to the primary oocyte secondary oocyte. Generally occurs before ovulation, except in horses and dogs secondary oocyte formation occurs after ovulation. At the time of ovulation oocit metaphase II stage of meiosis II. Meiotic division II continues when the spermatozoon through the zona pellucida and activate the secondary oocyte (Anon, 2009).
Ovulation
Ovulation is the release of an ovum from the ovary cells as a result of follicular rupture that has been cooked. The time needed by the whole process of ovulation depends on the location of eggs in the follicles. A short time when ovulation will the egg cell at the bottom of the follicle and will be long when the egg is near the stigma surface protruding ovaries (Anon, 2009).
Mechanism of ovulation:
a. Hormonal:
After the follicles to grow because of the hormones FSH from the anterior pituitary, the follicle cells are capable of producing sexual estrogen and progesterone. Both these hormones in small doses will cause the release of the hormone LH. LH hormone plays an important role in ovulation bluffing. Rupture of follicles occurred in the pressure of growing follicles and persobekan the stigma pale area because this area lacks the blood.
b. Neural:
Stimulation on the outer cervix, either during copulation or artificial mating will be forwarded by the nerves to the central nervous system which will be received by the hypothalamus. Will be realising hormone secreted LH and LH levels in the blood will increase, which causes ovulation (Anon, 2009).
From the remnants of follicles that had undergone ovulation will form a variety of fabrics are:
1. Corpus haemoragikum
After ovulation will be followed by providing more blood to the remnants of follicles. Hiperplasi occurred in hipertropi and weaving so tebentuk round objects protruding surface of the ovary, resilient, and red
2. Corpus luteum
As a result of the process of the corpus luteinasi by the influence of hormones haemoragikum LTH, there was further growth of these cells. New Tenenuan will change color to yellow and produces progesterone for long to be high at the peak of the cycle of sex.
3.Korpus Albikansia
Cessation of activity in the corpus luteum produces progesterone will cause degeneration of cells that had not obtained the shape of the blood supply becomes very small and pale. Ovulation in cows occurs about 10-12 hours after estrus ended. A disturbance at the time of ovulation does not occur can lead to fertilization and embryo development or disturbance. Ovulation disorders may occur due to deficiency or imbalance of the endocrine and mechanical factors (Anon, 2009).
Fertilization
Meeting / union of sperm cells with egg cells is called fertilization or fertilization. In normal circumstances in vivo, fertilization occurs in the area generally in the fallopian tube ampulla region / infundibulum. Spermatozoa to move rapidly from the vagina into the uterus, into the tube. This movement may be influenced also by the role of myometrial contraction and the wall of the tube which also occur during intercourse (Yosemite, 2009).
Then spermatozoa had events:
1. capacitation reaction: for a few hours, plasma proteins and glycoproteins that are in diluruhkan semen.
2. akrosom reaction: after close to the oocyte, sperm cells that have undergone capacitation will be affected by substances corona radiata of the ovum, so that the contents of the head area akrosom sperm are released and exposed to the corona radiata layer. At this time released hyaluronidase can dissolve the corona radiata, trypsine-like agent and lysine-zone that can dissolve and help the sperm through the zona pellucida to reach the ovum.
Once a sperm zona pellucida touch, there is a strong attachment and penetration is very rapid. Once a breach has occurred by a single sperm zones, a special reaction in the zone pellucida (zone-reaction) which aims to prevent the occurrence of sperm penetration by other again (Yosemite, 2009).
The main results of fertilization
1. fulfillment of returning the number of chromosomes from the merger of two haploid paternal half
and the mother would be a new individual with a diploid chromosome number.
2. determining the sex of the new individual will depend on the X or Y chromosome that
contained sperm fertilize the ovum.
3. cleavage and the beginning stages of the embryo formation and development of
(embryogenesis) (Yosemite, 2009).
Implantation
At the end of the first week (day-to-5 to 7) zygote reaches cavum uteri. At that time the uterus is in the mucus secretion phase under the influence of progesterone from the corpus luteum is still active. So that the endometrium lining the uterine wall into the blood vessel-rich estuaries and many uterine mucous membrane glands open and active. Contacts between the zygote stage to blastocyst in the uterine wall that state would trigger various cellular reactions, so that cells can trofobas zygote and held against infiltration of the endometrial epithelial lining of the uterus (implantation occurs). After implantation, trophoblast cells are embedded in the endometrium continues to grow, forming a network along with the maternal vascular system to be PLACENTA, which then serves as a resource for nutrition and oxygenation embrioblas network that will grow into a fetus (Yosemite, 2009).
Embryogenesis
Zygote started early mitotic division until a couple of times. Cells generated from each division are smaller than the size of its parent, called a blastomere. After cleavage of 3-4 times: 16 levels of the zygote enters the cell, called Morula stage (approximately on day-to-3 until 4 pascafertilisasi). Morula consisting of inner cell mass (a collection of cells on the inside, which will grow into the tissues of the embryo to fetus) and the outer cell mass (cell layer on the outside, who would grow up to placental trophoblast). At about the day-to-5 to 6, in the cavity between the inner cell mass of fluid seeps through the zona pellucida, forming a space between cells. Space between these cells and then come together and meet most of the mass of the blastocyst cavity form a zygote. Inner cell mass remained gathered at one side, still bordered by outer cell layer. At this stage in the zygote stage called blastula or blastocyst formation. Inner cell mass later called embrioblas, and then the outer cell mass called the trophoblast (Yosemite, 2009).
Birth
Parturisi is a birth process. Here the fetus is responsible for the initiation of birth, endocrine processes quite different from one species to another, in some species these processes can not be explained in detail. Increased fetal cortisol production occurs as a result of the change and maturity action hypothalamic-pituitary-adrenal fetus. It is estimated that the stress caused by the growing fetus because the placenta is no longer able to supply the needs and demands of fetal growth (Hary, 2009).
The incident that preceded the birth of endocrine, among others;
• Increased production of corticotropin-releasing hormone (CRH) by the fetal brain.
• Peningakatan production hormonr adenocrticotropic (ACTH) by the fetal anterior pituitary gland.
• Increased production of cortisol by the fetus galndula adrtenal
• Perubahamn placenta to estrogen progerteron
• Estrogen menstimuli myometrium to produce prostlagladin F2a (PGF2a) and also causes relaxation of the cervix
• PGF2a causes contraction of the myometrium will cause press uterin and intra memndorong toward cervic fetus.
• Oxytocin galandula be issued by the posterior pituitary and fetal stem spur cervic dilatation.
• Oksitocin menyebabakn kontrakasi myometrium.
Peptide hormone relaxin is produced by the placenta or the maternal corpus luteum in early kebuntingan. Relaxin also play a role in the relaxation of the maternal cervix before birth and affects the efficiency of contraction of myometrium (Hary, 2009).
Antenatal
The signs can be observed close to the birth during the end of the month kebuntingan, these signs include:
• Rotation of birth position
During kebuntingan, the fetus will fall down on your back with legs facing up. After rotation to the position of birth, the fetus will fall down on the thorax or abdomen with the front legs to be positioned at the end of the cornua near the cervix and nose located between the front legs. With this position, the birth easier.
• Changes gl.mammae
Gl.mammae growth can be seen during the late kebuntingan. This is caused by joint estrogen and progesterone stimulate the development of ducts and tissues gld.mammae secretion. Approaching the birth gl.mammae be enlarged and filled with milk. Milk synthesis is a function of prolactin in collaboration with other hormones. When oxytocin is released during birth, there was milk let down, causing the milk out of nipples (Hary, 2009).
• Other Changes
Closer to the birth of the Relaxin in cooperation with estrogen will cause relaxation of the pelvic ligaments and cervix channel expansion. Lig pelvic relaxation around the base of the tail will cause the base of the tail is more prominent. Vulva are tender and swollen. Mucus look like when leleran of the vulva sel2 estrogen causes the cervix secrete mucus epithel new, so dilute mucus plugs. Sheep will try to leave the group. Sheep will find a place to hide during the birth (Hary, 2009).
Stages of birth:
The first stage of birth:
Dipercya this stage lasts 6-12 hours. Ewe will separate themselves from the group and look gelidah and scratching the ground. Some of the ewe does not show any sign of the first stage of birth.
The second stage of birth:
This phase lasted ½ -1 hour and maybe a little longer on the new ewe gave birth the first time. The majority of lambs entering the canal on the anterior longitudinal presentation dengfan same posture like a calf. Some lambs were born with a presentation posteriore with rear legs that protrude into the canal. Little lamb in the anterior presentation can sometimes be born with one foot in front of shoulder flexion. Normally the female will lay the sheep to give birth, with a strong push and lifted his head up and bellows. Many choose ewe lying back position. Against the wall or fence for the second melahirkan.tahap repeated during the next lamb born. Approximately 50% of children born with amniotic sheep intact (Hary, 2009).
The third stage of birth:
The placenta is normally off within 3-4 hours after acquisition last lamb.
BIRTH PROCESS
Initiation of hormone:
Hormonal patterns during the final stages of birth kebuntingan set. Levels of estrogen, progesterone, and relaxin highly visible so that it can be seen that the mechanism that initiates the release of birth by fetal cortisol. The increase in cortisol production and release caused a greater than estrogen by the placenta that initiate the release of PGF2a from uterusPGF2a that cause CL regression and a drop in progesterone. The placenta is the main source of progesterone in sheep during the 2 / 5 final kebuntingan (Hary, 2009).
Apparently an increase in fetal cortisol causes a change in the placental enzyme which produces progesterone to estrogen conversion. Placental estrogen causes the release of PGF2a from the uterus of sheep but a decrease of progesterone seen before PGF2a increases.
Oxytocin apart when fetal movement sensory nerve merangang cervix and vagina. The highest oxytocin Konsenjtrasi seen during fetal expenses. Small spike seen during the release of placental expenditures greater PGF2a caused by oxytocin. An increase in antenatal parent cortisol may be caused by stress parturisi and not involved in the regulation parturisi. Prolactin surge associated with the synthesis of milk and not with parturisi.
The main physiological occurrence in parturisi:
Dilatation of the cervix to track fetal
Initiation of cervix dilatation caused by relaxin in collaboration with estrogen increases. Cooperation these hormones soften the cervix and cause epithelnya cells secrete mucus. Subsequent dilation occurs when the uterine contractions push allanto-chorion and amnion kemdian toward the cervix. Allanto-chorion may be broken during this process. Amnion usually not broken until the fetus into the cervix (Hary, 2009).
A number of factors involved in initiation and continuation of uterine contractions that occur simultaneously with the dilatation of the cervix and then continued for several hours after spending the fetus.
Progerteron depression, then wrote increased estrogen resistance caused by the loss of myometrium contraction teerhadap and make it more active on the nature agenagen stimulating. Effuse uterine contractions and fetal placenta (Hary, 2009).
Initial contraction of the uterus may be caused by PGF2a when released from the endometrium with an increase in estrogen. This initial contraction is weak, irregular, occurs kira2 with 15-minute intervals when the fetus driven into the cervix sensory nerve impulses cause the release of posterior pituitary oxytoxin.
The increased release of oxytocin was accompanied by the release of a larger PGF2a. Oxytoxin acts directly on the myometrium, or indirectly through the stimulation of the release of PGF2a larger, causing uterine contractions will be stronger, more rhythmic and more frekuen PGF2a and Oxytoxin peaked during the release of fetal
Mortality Fetal anoxia caused by other factors which may cause strong contractions labih end-stage approach when the fetus removed. When the uterus to contract causing reduced blood flow to the fetus, the oxygen supply running low, which causes increased activity associated with anoxia. Mechanical movement of the fetus which lead to uterine contractions cause stronger contractions.
A moment fetus seblum expenses, uetrus contractions became regular, strong and frekuen, which happened kira2 with 2-minute intervals that lasted for 1 minute kira2. Contraction of abdominal muscles will help end the fetus expenses.
After spending decreased fetal uterine contractions. This reduction will menlanjut for 1-2 days. Yg continuous contraction is responsible for expenses or liquid membranes and placental fragments of placental tissue is left in the uterus. Oxytosin second spike expenses associated with the placenta (Murti, 2009).
Disruption of ovulation may be delayed ovulation, anovulation and folikuler sista.
Delayed ovulation (Delayed ovulation)
Delayed ovulation is one of the causes of infertility. This incident can menyebebkan IB marriage or not on time so that fertilization does not occur and eventually failure kebuntingan. The cause of ovulation could be delayed due to low levels of LH in the blood or because diperpanjangnya period folikuler. The diagnosis can be done is folikelnya PR 24-36 hours after estrus ended. Symptoms that appear in this case is the occurrence of repeated mating. Therapy can be done with injesi GnRH (Gonadorelin microgram 100-250) when the IB or the provision of hCG (Admin, 2008).
Sista Ovaria
Cystic say when Ovaria contains one or more structures that contain fluid and larger than the mature follicle. The existence of these sista cause follicular de graf do not ovulate (anovulation), but experienced regression and atresia or experience that luteinisasi follicle size increases, the granulosa cell layer degeneration and memetap at least 10 days (Admin, 2008).
As a result the cows became anestrus or nimfomania. Ovaria sista is one of the causes of infertility. Predeposisinya factor is hereditary and diet. Cause sista is ovaria ovulation and endocrine disorders. Treatment can be with the LH / hCG, GnRH, PGF2α (Admin, 2008).
Based on the events are divided into ovaria sista sista folikuler, sista sista korpora luteal and luteal.
A. Sista folikuler
Is the set of follicle does not ovulate due to low hormone LH. Number sista be one or more on one or both ovaries. Symptoms folikuler sista is continuous estrus (nimfomania) if sistanya much or anestrus if sistanya bit and anovulotorik nature. If the event becomes chronic nimfomania usually causes sterility hump. On per rectal examination of the ovaries will be felt smooth surface, diameter> 2.5 cm, thin walls and if there is pressure fluctuations. Treatment can be done by granting enukleasi and hormone LH or HCG (Admin, 2008).
B. Sista luteal
Formed because the follicle has luteinisasi result in a sudden increase in LTH. Genesis sista luteal ovary is usually single and often occurs in the production of dairy cows high. Symptoms luteal sista is not showing estrus (anestrus) and its anvulatorik (inability to ovulate). On per rectal examination of the ovaries palpable diameter> 2.5 cm, the surface of the ovary and luteal clear boundary, the walls thick and feels springy when pressed. Treatment with PGF2α or giving way to the sista enukleasi luteal (Admin, 2008).
C. Korpora sista luteal
Sista is formed from follicles which had ovulated and then had some luteinisasi so there is the center of the hollow and filled with fluid., Usually single on one ovary. Basically, this condition have a normal cycle, estrus and ovulation and fertilization can occur but the condition can not be maintained conception because of low progesterone in the blood. Manifesti of luteal korpora sista characterized by repeated mating. On per rectal ovarian palpation palpable rubbery when pressed, he ether of> 2.5 cm and thick-walled. Treatment with PGF2α if it does not happen kebuntingan (Admin, 2008).
Anovulation
Often associated with true anestrus, but estrus can occur but the follicle regresses or atresia. Also often occurs in cows after partus, where there is a marked ovarian activity by the estrous but not weak because the follicle is growing at a maximum, and lost (anestrus) because the follicle regresses. Not until the ripe follicle development and ovulation is not possible due to low levels of FSH and LH hormone. Sometimes the follicle does not reach the size of regression and 2-2,5 cm, but the walls that have similar luteinisasi corpus luteum or follicles develop into follicular de graf but fail to ovulate due to hormone disorders gonadotropin release. Clinical symptoms in this case the estrus again after marriage or the marriage over and over. On per rectal examination of the ovaries palpated rounded or smooth, no fluctuations, solid as the corpus luteum. Therapy using HCG or GnRH (Admin, 2008).
Tidak ada komentar:
Posting Komentar