Term
| How could a cow's body condition score at the onset of her lactation potentially impact her ability to maintain a 12-13 month calving interval (Answer this question based on uterine involution, cyclicity resumption, re-breeding and gestation length)? |
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Definition
| The dry period is used to 'rest' and 'recover' the animal's udder health, and to do the final adjustment to the pregnant cow's body condition (fat reserves) if needed. If the animal needs more than an increase in BCS of more than .50, then the weight increase should take place during her latter days of lactation rather than when she is dry. Animals that are too fat (BCS > than 3.75) or thin (BCS < 3.25) at the time of calving have more post calving related health (health includes reproduction) issues. These issues can slow down the rate of uterine involution, which in turn could influence the animals potential fertility at the end of the voluntary wait period. If the uterus is excessively challenged and/or the cow's defense capabilities are suboptimal, then recovery is delayed. With a lower body condition score, and if the animal is otherwise healthy, the uterus can involute so that it is histologically normal by 45 days postpartum. However, since the first 8 weeks of the lactation are associated with peak energy demands due to production, body maintenance and growth (heifers), then these demands deplete the fat reserves of the thin animal leading to a longer negative energy balance. As a result the animal remains anestrous for a longer than necessary time. This may lead to an inability to breed the animal at the end of the VWP and thus, the animal may not be able to maintain a 12-13 month calving interval. |
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Term
| Describe the effect that the bedding has on the comfort of lame cows. |
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Definition
| Lame cows in stalls with firm surfaces tend to have an increase in their standing time due to fear and pain, both as they lie down and then when they stand back up. Loose bedding, such as sand, however allows the animal to spread out the weight over a larger area, especially the pained areas of the hooves, and when down, the remainder of the body is also comfortably supported. Then when the lame cow stands (cattle-rear legs up first), the weight is distributed well over the hooves, rather than just the tip of the hoof as it would be on mattresses. Healthy cattle can use firm bedding material, such as mattresses, however, there can be an increased risk of other leg problems. For example, if the normal cow excessively rubs her legs against the abrasive mattress, then areas such as the hocks can become irritated, leading to lameness issues. |
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Term
| Calving in a maternity area that is poorly sanitized, can increase the risks of? |
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Definition
| Neonatal disease outbreaks, maternal mastitis development, increased uterine infections and other disease potentials. |
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Term
| Firm bedding material is acceptable for healthy, non lame cows, but is contraindicated for lame animals. |
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Definition
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Term
| When is the best time to correct a thin cows body condition score (adding a .75+ to her score)? |
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Definition
| During the latter phase of her current lactation. |
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Term
| What is the ideal body Condition Score (BMS) range for dairy cattle by the end of her dry period? |
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Definition
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Term
| If the calving pen is poorly sanitized, then what are the relative risks? (single or multiple answers are offered)? |
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Definition
Neonatal disease outbreaks
maternal mastitis development
increased uterine infections
other disease potentials |
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Term
| What are the three terms, presentation, position and posture telling us about the fetus and the parturition? |
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Definition
Presentation: This term indicates whether the fetus is entering the pelvic canal head first (anterior) or rear first (posterior), or is structurally abnormal (dorsal-the back or ventral-the abdomen). The term also compares the fetal spine to the maternal spine (longitudinal or transverse). The List: Anterior or posterior longitudinal or dorsal or ventral transverse. If a vaginal delivery is possible in the anterior or posterior presentations, the information helps determine the directions of the pull and the rapidity that the fetus must be delivered (in the posterior presentation the umbilicus is quickly compressed). Transverse presentations are associated with fetal monsters (c-sections, fetotomys). Also, these images will give you an idea where the fetotomy cuts may have to be made, or which part of the fetus is accessable after the uterine incision during the c-section.
Position: This indicates the position of the dorsum of the fetus to the maternal pelvis in anterior or posterior presentations. They are: Dorso-sacral, dorso-pubic, right or left dorso-ilial. If the fetus is in transverse presentation the terms are left or right cephalo-ilial. This information may suggest a uterine torsion with a dorso-sacral position. With a transverse, knowing where the head is helps with fetotomy attempts.
Posture: This is the fetal extremities relative to the fetal body (normal or flexed). In most cases the posture must be normal for a vaginal delivery. |
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Term
| What does the term 'hiplock' mean, and how is it prevented? |
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Definition
| Hiplock is a term meaning that the widest portion of the fetal pelvis has locked into place in the narrowest part of the maternal pelvis. In order to prevent this occurance, the fetal hips are rotated so that the widest fetal portion is passing through the widest maternal portion. Although hiplock only applies to the hips it is a good idea to also rotate the fetus so that the shoulders also pass through the largest portion of the maternal pelvis. |
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Term
| How would you treat a cow with a fresh uterine prolapse? |
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Definition
| First either have the cow standing or at least in sternal recumbancy. Briefly, the uterus is cleaned and lifted (at least) to the level of the pelvic floor. The lifting helps the veinous blood return. Next the uterus is pushed into the vagina by working around its circumference. After it is returned, be sure to completely reposition both horns (use a uterine flush with fluids to pressure the tips back into place). Suture the labia together for 24-48 hours (allowing enough space for urination). Uterine antibiotic infusions are commonly administered. |
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Term
| A properly positioned obstetrical chain helps prevent? |
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Definition
| Hyperextension of the joints |
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Term
| If a hiplock takes place in an anterior presentation, then continuous traction should be applied in a caudal and slightly dorsal direction after the living fetus has been repelled, and it's hips rotated. |
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Definition
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Term
| Usually a clinical fetotomy case requires a full series (5-6) of cuts. |
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Definition
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Term
| The umbilical vessel is compressed sooner when the fetus is being delivered in the posterior presentation. |
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Definition
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Term
| If the cow is standing and the bottom of the fetal hooves are past the labia and pointing up, it would suggest that the fetus is in the ____________ presentation. |
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Definition
| Posterior (Longitudinal, Dorso-Sacral) |
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Term
| Outline the benchmarks describing a normal rate of uterine involution and the resumption of cyclicity in a normal post-calving cow (Involution components: placental expulsion, lochia discharge, decrease in uterine size and histological changes. Cyclicity components: cohort development by time and the dominant follicle ovulation) . |
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Definition
| Post-calving contractions continue after the fetal expulsion. Generally the placenta is passed in < 12 hours after calving. Strong contractions continue for a few days, then slowly diminish over the next week or so-interesting in that injectable oxytocin can be theraputically given over this time. The lochia typically is no longer discharged past 2 weeks postpartum. By 30 days the uterus has involuted to slightly larger than its pregravid size. Histological involution (recovery) is felt to be complete by 45 days. The resumption of cyclicity usually resumes sometime between 3-4 weeks after calving. At approximately 1 week after calving, follicular cohorts begin to develop and regress. Once the cow passes the point of her maximum negative energy balance, the dominant follicle of the cohort ovulates (a silent estrus). Subsequent ovulations have a normal expression.(of estrus) since they are in conjunction with the declining progesterone and rising estrogen levels. Depending on the cause(s) remember that uterine involution delays can be associated with the development of various clinical problems. |
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Term
| Outline the steps involved in the process of placental expulsion and retention. |
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Definition
| Pre-partum tissue maturation involves the loss of the maternal cells which interdigitate with the fetal components of the placentomes. During parturition, the mechanical pressure of the uterus squeezing against the fetus, along with the transient decrease in the uterine blood flow, continues to weaken the caruncular-cotyledonary interface. Once the fetus is expelled, the early initial involution of the uterus decreases the caruncular size, additionally separating the tissue. The immune function, hormone imbalances, trauma and management issues can all play a role in promoting placental retention. |
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Term
| An enlarged postpartum uterus at 30 days indicates that the cow is involuting abnormally and has a case of clinical endometritis. |
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Definition
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Term
| Why can the early secretion of progesterone be problematic? |
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Definition
| The cow may develop clinical endometritis or a pyometra. |
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Term
| Intrauterine antibiotics are the primary treatment for postpartum pyometras. |
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Definition
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Term
| Why does a cow that retained her placenta take longer to get pregnant? (multiple answers) |
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Definition
Her uterine involution rate is slowed down.
She takes longer to develop a preovulatory dominant follicle. |
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Term
| You have finished a 30 day palpation-ultrasound (U/S) exam on a high producing Holstein cow which and recorded the following information: The diameter of the left horn was 35 mm, the right horn 45 mm and the cervix internal cervical os was at at 50 mm. No fluid was visible on U/S and the vaginal speculum examination showed a slightly abnormal (cloudy) discharge. There are multiple 5-8 mm follicles on the left ovary but the right has no significant follicular structures. You estimate her body condition score to be about 2.75. What can you theorize about this animal? Also, the owner wants to give a GnRH injection to get the cow to ovulate. |
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Definition
The horns and cervical sizes suggests a delay in the rate of her uterine involution (remember to measure the internal os as the external can stay enlarged after a normal involution rate). This enlargement could be subsequent to a dystocia, retained placenta or management issues (stress, nutrition, calving sanitation area, and so on). Also, if the owner had noted or treated any abnormal lochia, that would also suggest involution problems due to excessive level of uterine contamination. The findings on the U/S are unremarkable, but the speculum examination, in association with the lack of follicular development on the ipsilateral ovary to the right horn suggests that bacterial contamination may be interfering with follicluar development. Also, the body condition score suggests that nutrition may be a factor. Adequately fed animals should not drop more that .25-.50 in their postcalving BCS, so she has either lost too much weight or had a low BCS at calving.
Due to the small size of the follicles, particularly on the ipsilateral ovary, and her BCS, any treatment is likely to be ineffective. |
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Term
| Describe the palpable findings that you would expect to find if the cow had an: (1) Ovulatory depression, (2) a corpus hemorrhagicm, (3) a corpus luteum, or (4) a corpus albicans. Also indicate what the follicles feel like whern they are 5-8 mm vs. 10-15 mm in diameter. |
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Definition
| The ovulatory depression is a very soft, depressible area (authors note-it feels soft and flat to me on palpation). The corpus hemorrhagicum begins as a soft small spherical structure (dividing luteal cells and blood) which becomes larger and firmer as it matures into a corpus luteum. The mature corpus luteum distorts the width of the ovary, generally ranges in size between 25-35 mm in diameter and is firm. The corpus albicans begins forming after the corpus luteum regresses, becoming smaller and much harder. Smallo follicles feel firm, while larger ones are softer and 'fluidy'. |
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Term
| What drugs can be used to treat a cow that has a either a non-luteal (thin walled) follicular cyst or a luteal (thick walled) cyst? |
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Definition
| GnRH or LH: Causes the thin cyst to produce luteal tissue, or the thick cyst to make additional levels, both of which may then produce adequate levels of progesterone (~80% effective). The treated cyst would then act like a CL. Prostaglandin: Causes luteal tissue regression, so it may be an effective treatment with the thick cyst, but obviously has no effect on the thin cyst. CIDR-B: This acts like a CL. so that after its removal, the LH level rises, which creates additional luteal tissue. |
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Term
| Why is the luteal tissue, which has formed into a CL, have a darker grey image on ultrasound? |
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Definition
| There is a greater volume of blood in the luteal tissue. |
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Term
Indicate the action and use for each drug listed below as they relate to estrus cycle control and synchronization.
Prostaglandin.
GnRH.
Intravaginal Progesterone Releasing Device, and
Estrogens. |
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Definition
Prostaglandin: Used to lyse a sensitive CL, generally given between the 5th-6th day of diestrus up to the 16-17th day. Depending on the development of the current follicular cohort, the cow comes into estrus in 3-5 days.
GnRH: GnRH induces an LH surge, even in the presence of high progesterone levels. GnRH is used to remove the dominant follicle of a cohort during diestrus via luteinization in order to permit the recruitment of a new cohort. GnRH is also used to initiate the final maturation sequence with a dominant follicle during periods of low progesterone for timed breeding programs. Remember that the follicle has to be mature enough to respond to the LH surge.
Intravaginal Progesterone Releasing Device: A CIDR is used to maintain an artificial CL, which prevents the cow or heifer from coming into estrus. It also helps suppress her LH secretion which limits the follicular growth of developing cohorts.
Estrogens: These are currently illegal to use in food producing animals. Estrogens have a profound suppressive effect on FSH secretion. |
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Term
| What is the major factor that influences a follicle's response to a GnRH injection during diestrus? |
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Definition
| The maturity of the dominant follicle. |
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Term
| Why is the time from the injection of prostaglandin to ovulation in a diestrous cow so variable? |
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Definition
| The injected cows have follicular cohorts in different stages of development/regression. |
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Term
| A CIDR-B is designed to releases what hormone (in the United States)? |
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Definition
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Term
| Which answer describes the desired use of the first and second GnRH injections used during an OvSync protocol? |
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Definition
| The first GnRH injection is essentially used to turn any dominant follicle into a CL, while the second is used to initiate the normal breedable ovulatory |
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Term
| What 3 parameters have to co-exist in order to produce a freemartin heifer, and what would you find on palpation? |
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Definition
1. The twin pair must be male-female.
2. There must be placental anastomosis
3. The male must be viable past 40-45 days of gestation
The true freemartin has a significantly altered reproductive tract and they all have seminal vesicles. |
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Term
| What is the palpable pathopneumonic finding in a freemartin heifer? |
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Definition
| Since the amount of reproductive tract material is variable, the finding that all the freemartins have is seminal vesicles. |
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Term
| What does the term pseudohermaphrodite mean? |
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Definition
| The term means that the animal has ovarian tissue but looks like a male or has testicular tissue but looks like a female (the most common pseudohermaphrodite). |
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Term
| What if a heifer weighs only 65% of her mature weight when she calves? |
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Definition
| She has a higher tendency to have a dystocia and a prolonged anestrous period. She should weigh 85% of her adult weight at her first calving. |
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Term
| In general the fertilization rates are the same on a normal and a repeat breeding cow. |
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Definition
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Term
| It would generally be a waste of time to transfer a viable embryo from a repeat breeding donor animal. |
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Definition
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Term
| Which answer(s) are correct concerning heifers calves born along with a bull calf? (multiple answers) |
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Definition
She likely will have seminal vesicles.
They are XX-XY chimeras.
Occasionally she is found to be fertile. |
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Term
| What is/are a likely outcome(s) if a late maturing heifer (due to poor weight gain) in a group, is bred, becomes pregnant and is maintained on a marginal diet? Circle all responses that apply. |
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Definition
She is more prone to a dystocia.
She will subsequently tend to calve later than the others in the group.
She is at a greater risk to be culled from the herd. |
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Term
| Which answer correctly identifies the source of the tissue forming the placentome? |
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Definition
| The placentome is comprised of fetal tissue (cotyledon) and maternal tissue (caruncle). |
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Term
| Which of the positive, palpable signs of a normal pregnancy is the most accurate (not using ultrasonography) for estimating the true gestational length? |
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Definition
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Term
| What is the significance of both middle uterine arteries being the same size, with fremitis, at 6 months of gestation? |
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Definition
| The cow is carrying twins. |
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Term
| If you intentionally crush the amniotic vesicle, how soon do most animals return to estrus? |
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Definition
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Term
| What are the clinical similarities and differences between a mummified and a macerated fetus? |
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Definition
| Both conditions require the dead fetus to have enough of a skeleton (> 3 months of gestation), so that the bones persist. The mummified fetus is sterile, while the macerated is associated with a partially open cervix, allowing bacterial entry. Both have a 'retained' corpus luteum. The prognosis for fertility after the successful expulsion of a mummified fetus is good, while the fertility following the surgical removal of a macerated fetus is poor to grave. |
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Term
| What are the similarities and differences between hydrallantois and hydramnios? |
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Definition
| Hydrallantois accounts for the majority of the hydrops conditions. Allantios is associated with uterine/placentas disease, whereas amnios is related to an abnormal fetus. The fluid accumulation is rapid with allantois, and slow with amnios. With allantois, the fetus and placentomes cannot be palpated, whereas with amnios the placentomes are detectable. Both conditions are treated in a similar manner (induced parturition), however, only the amnios should be considered for rebreeding to a different bull. |
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Term
| How would you diagnose a uterine torsion? |
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Definition
| There may be an abnormal fetal position if the rotation is other than a 360 degrees. Otherwise, there tends to be minimal levels of straining, and there may be vaginal spiraling in one direction. On palpation, one broad ligament is pulled higher than the other and is tense. Otherwise, many cows do not show much of a problem until the condition has gone on for hours to days. |
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Term
| Outline the major steps in the initiation of a normal parturition. |
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Definition
| The fetus initiates parturition by some unknown maturation factor(s) at the level of the hypothalamus. The consequence is the release of corticosteroids from the fetal adrenals which in turn causes the placentomes to secrete estrogen and prostaglandin rather than progesterone. The prostaglandin secretion causes lysis of the CL, removing the luteal progesterone source and the estrogen promote oxytocin receptor expression, which will enhance contractility. |
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Term
| When considering abnormal pregnancies or gestational problems, which situations lead to culling the cow because she cannot produce live calves, and which conditions are (potentially) successfully 'treatable'? |
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Definition
Conditions leading to culling since the production of live calves is not or only rarely possible: Fetal maceration, hydroallantois and severe cervical-uterine scarring.
Treatable conditions: Fetal mummification, hydramnios, vaginal prolapse, uterine torsions and less severe cervical-uterine scarring |
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