ARTIFICIAL INSEMINATION IN FARM ANIMALS - Phenix-Vet

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162Artificial Insemination in Farm Animalsaccompanied by rapid weight loss and BCS, which submits the ovarian follicles to largemetabolic changes. Such variations affect the normal development of follicles and lowerlevels of progesterone. This scenario is associated with reduced fertility (Butler and Smith,1989). Indeed, Walters (2000) found that the decrease in BCS after delivery decreased by 42%the quality of oocytes collected by follicular aspiration from Holstein cows.Vizcarra et al. (1998) inferred that the nutritional status influence postpartum luteal activityand concentrations of glucose, insulin and saturated fatty acids, which are high in cows withhigh body condition score at calving. According to Walters (2000), this framework explainswhy the delay of first ovulation in postpartum cows with negative energy balances. In fact,low plasma levels of glucose, insulin, non-esterified fatty acids and growth factor type 1insulin are associated with inhibition of pulse frequency of luteinizing hormone andestradiol production by the dominant follicle (Walters, 2000). In cows that consumeadequate dry matter during this period, follicular development is apparently normal(Staples et al., 1991). Already decreased by 1.0 point in the body condition score in these firstfive weeks postpartum resulted in lower fertility at first service (Britt, 1992). In contrast,over-conditioning, ie very high body condition score cows at the end of the pre-deliverycaused an increase in service period and embryonic mortality (Flipot et al., 1988).The productivity and profitability of farms are closely related to achieving highreproductive rates, which are only achieved through the adoption of certain managementpractices. Among these, science-based nutrition should provide the matrix of metabolicconditions ideal to meet certain strategic moments of the production cycle, such as thebreeding season, the season of birth and lactation season. In this context, the body conditionscore is a useful tool in assessing the nutritional status of the animal and therefore hasstrategic application in reproductive management of herds that are artificially inseminated.8. Evaluation of female gynecologicalAll females of reproductive age in a herd must be submitted to gynecological examinationfor selection of suitable animals for artificial insemination program. This is an internalexamination by rectal palpation, ultrasound and vaginoscopy and can be complemented bylaparoscopy and biopsy. On rectal palpation and ultrasonography are checked the size,consistency and contraction of the uterus, uterine horns and symmetry. In the ovaries areobserved consistent form and size of follicles, cysts and persistent corpus luteum.Vaginoscopy complements rectal palpation and ultrasonography, because it turns out theshape of the vaginal portion of cervix, the opening degree of the cervical canal, mucosacolor, moisture content and characteristic vaginal and cervical mucus.The pelvic examination should be thorough, seeking to know and understand the bestpossible animal's reproductive status, either for a simple confirmation of pregnancy or toidentify diseases or reflection of management that is harming their reproductive efficiency.Gynecological examination involves a complete evaluation of all components of the externaland internal genitalia, with emphasis on the ovaries, combining the findings of theexamination with a score of animal body, with its history and with the herd.For purposes of gynecological evaluation should consider the following groups of animals:from 20 to 30 days postpartum, postpartum with abnormal vaginal discharge, irregularestrous cycles, not seen in estrus 60 days postpartum; covered or inseminated by two ormore times, and that return to estrus 45 days after artificial insemination. In the historicalsurvey of the animal should always consider the age, number of childbirths and theirconditions and cyclicality observed, as these factors may reflect the ovarian function and
Particularities of Bovine Artificial Insemination 163reproductive efficiency. Are essential, too, about the coverage, treatment for retainedplacenta and uterine infection, drugs and dosages, treatment outcome, nutritional programfor the animals used in pre-natal and post partum, body condition at calving, stage lactation,milk production and herd health program.It is crucial at the end of gynecological examination, classify the animals examinedaccording to their reproductive status in pregnant and not pregnant, the latest beingidentified as normal or with any individual or reproductive problems reflecting amanagement problem. The results of gynecological examination of different groups ofanimals held in a coherent and detailed by a veterinarian, provides a satisfactoryunderstanding of the breeding herd during the exam, allowing them to be defined andadopted measures to keep the reproductive efficiency of flock.9. Diagnosis of pregnancyPregnancy diagnosis is an important tool for the management of rural property. This mustbe done by a veterinarian trained at around 28-30 days after artificial insemination by rectalpalpation and / or ultrasonography. There are other methods that can be used for diagnosisof pregnancy such as: no return to service, measurement of progesterone, pregnancyspecificproteins, estrone sulfate, breast enlargement and abdominal distension. Theaccurate diagnosis of pregnancy is important in establishing and maintaining optimalreproductive performance. The producer should know as early as possible if the female iscovered or not pregnant for it to be inseminated again.A cow is diagnosed not pregnant if she has been observed in estrus approximately 21 daysafter artificial insemination. The percentage of cows not observed in estrus around thisperiod is known as the rate of no return and is not a method to estimate pregnancy rates. Asthe percentage of cows ovulating truly seen in estrus is often low, the rate of return notoverestimate the rates of pregnancy. If a cow is in estrus detected three weeks after artificialinsemination, it can still be pregnant and her artificial insemination can cause miscarriage.One must be careful to confirm that it is true and not in heat pregnant through othermethods of pregnancy diagnosis.The detection of pregnancy by measurement of hormones, especially if they occur in milkhas advantages when interference is minimal with the cow and risk-free pregnancy. Themeasurement of progesterone to verify pregnancy also offers the possibility of diagnosingthe twenty-first day. In pregnant cows, progesterone concentrations in milk and bloodremain high between the twenty-first and twenty-fourth day after ovulation, when theywould be basal in the animal not pregnant. The simplest procedure is to obtain a sample ofmilk from the cow 21 days after artificial insemination. If the progesterone level is low, thecow is not pregnant. If the progesterone level is high, the cow may be pregnant.The factor of early pregnancy is a gestation dependent protein complex that has beendetected in the serum of various species. It is detected using an immunological technique,the rosette inhibition test. It is expected that this substance appear in the serum soon afterconception and disappear very quickly after embryonic death. Two additional proteins,protein B pregnancy specific bovine and bovine pregnancy associated glycoprotein, can alsobe measured during early pregnancy in the cow.The availability of ultrasound has been a major advance in the diagnosis and monitoring ofpregnancy reproductive taking the advantage of not being invasive. The baby begins to fillthe uterine horn near the seventeenth day of gestation and can be seen as an non-echogenicarea. In the nineteenth day, the amniotic sac has expanded considerably and the lumen of
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VIContentsChapter 9Evaluation of a
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ARTIFICIAL INSEMINATION IN FARM ANIMALS - Phenix-Vet

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