Estimation of superovulation response in donor cows

Estimates were made of the superovulation response in donor cows using ovarian size, the number of corpora lutea (palpated per rectum) and blood progesterone levels. Neither the estimated number of corpora lutea nor ovarian size gave a satisfactory prediction of superovulation response. There was a large discrepancy between the number of corpora lutea present on the ovaries of nine superovulated cows (166) and the estimated number (106). All the corpora lutea on superovulated ovaries were smaller than normal (1.95 g). Blood progesterone levels at the time of embryo recovery were correlated with both the number of corpora lutea on the superovulated ovaries (r = 0.9, P less than 0.001) and the weight of the corpora lutea (r = 0.95, P less than 0.001). There were 67 embryos and ova recovered from the nine donors, representing 40 per cent of the actual and 63 per cent of the palpated corpora lutea. However, neither ovarian size, the number of corpora lutea nor blood progesterone levels were correlated with embryo production.     

Serum progesterone concentrations associated with superovulation and premature corpus luteum failure in dairy goats.

The incidence and cause of premature corpora lutea failure and the response to luteinizing hormone treatment was investigated in superovulated dairy goats. Does were treated with 1000 IU pregnant mare serum gonadotropin intramuscularly, followed by either luteinizing hormone (treated group) or saline (control group). Serum progesterone concentrations were used to monitor corpus luteum function. The dose of pregnant mare serum gonadotropin used induced superovulation in a majority of the does, but the responses varied depending on the time of year. Premature regression of the corpora lutea occurred in 4 of 18 does after pregnant mare serum gonadotropin treatment, but there was no difference in the incidence of corpora lutea failure between treated and control groups. Decreases in serum progesterone concentrations were evident by day 3 after ovulation in does that experienced corpora lutea failure indicating this to be the critical time for premature regression of the corpora lutea in superovulated does.     

An experiment to measure the dose-response relationship of ovulation rate to FSH in cows selected with a history of twinning

Fifteen mature cows and 12 two-year-old heifers were superovulated with purified follicle stimulating hormone (FSH-P) to study the relationship between FSH-P dose level and response (measured as number of palpated corpora lutea (CL) and plasma progesterone concentration). The cattle came from a high prolificacy breeding herd for which cows were originally purchased after producing at least two sets of twins; the heifers were bred in the herd. At dose levels of 8, 16, 24 and 28 mg FSH-P in cows, averages respectively of 2.3, 3.5, 6.9 and 11.1 palpable CLs were found. There was an average difference in response of two CLs between heifers and cows (higher in heifers, though not significantly so). The relationship found between progesterone concentration and CL number could be a useful indicator of superovulation success in future experiments. The regression for cows was 1.25±0.11 ng/ml progesterone per unit increase in CL number, with a correlation of 0.92 between the two variables over the CL range 1 to 25. The corresponding value for heifers was 2.74±0.24 ng/ml per CL (correlation 0.94), or 2.50±0.40 ng/ml per CL (correlation 0.83) if one record (29 CL, 84 ng progesterone/ml) was excluded.     

An experiment to measure the dose-response relationship of ovulation rate to FSH in cows selected with a history of twinning

Fifteen mature cows and 12 two-year-old heifers were superovulated with purified follicle stimulating hormone (FSH-P) to study the relationship between FSH-P dose level and response (measured as number of palpated corpora lutea (CL) and plasma progesterone concentration). The cattle came from a high prolificacy breeding herd for which cows were originally purchased after producing at least two sets of twins; the heifers were bred in the herd. At dose levels of 8,16, 24 and 28 mg FSH-P in cows, averages respectively of 2.3, 3.5, 6.9 and 11.1 palpable CLs were found. There was an average difference in response of two CLs between heifers and cows (higher in heifers, though not significantly so). The relationship found between progesterone concentration and CL number could be a useful indicator of superovulation success in future experiments. The regression for cows was 1.25 +/- 0.11 ng/ml progesterone per unit increase in CL number, with a correlation of 0.92 between the two variables over the CL range 1 to 25. The corresponding value for heifers was 2.74 +/- 0.24 ng/ml per CL (correlation 0.94), or 2.50 +/- 0.40 ng/ml per CL (correlation 0.83) if one record (29 CL, 84 ng progesterone/ml) was excluded.     

Assessment of superovulatory responses in terms of palpable corpora lutea and embryo recovery using plasma progesterone in yaks (Poephagus grunniens L.)

Plasma progesterone profiles were used to assess superovulatory responses in cyclic yaks (n=10) in terms of the number of ovulations and the number of embryos recovered. The animals were synchronized into oestrus following Ovsynch treatment. All the animals received a total of 200 mg Folltropin divided into morning and evening and spread over 4 days, beginning on day 10 of the oestrus cycle (day of expected oestrus=day 0). Plasma samples for progesterone estimation were collected daily starting from the day of expected synchronized oestrus to the day of flushing. All the animals were palpated per rectum on the day of flushing in order to record the number of corpora lutea. Of an estimated 27 ovulations from the nine yaks, only 16 embryos were recovered. Plasma progesterone profiles from individual yaks suggested that a poor superovulatory response in terms of embryo recovery in some animals was caused by the lysis of corpora lutea before flushing which was carried out 7 days after superovulatory oestrus. It was suggested that flushing 5 days post superovulatory oestrus could improve the superovulatory response in this species.     

Superovulation beim Rind: Hormonprofile bei Stimulation mit Serum-gonadotropin (PMSG) bzw. hypophysärem FSH*)

Contents: Superovulation in cattle: Hormonal profdes during superovulation with PMSG or pituitary FSH.: Hormonal profiles for LH, FSH, PMSG, progesterone in peripheral blood and oestrogens in urine during superovulation with PMSG (1500–3100 IU i. m.) or pituitary porcine FSH (5 mg i.m. 2 times daily for 5 days) were evaluated radioimmunologicaly. Two days after the begin of treatment luteolysis was induced by means of 0.5 mg Estrumat® i. m. The experiments were performed with 14 heifers and 2 cows. Blood samples were taken in 6 or 12 h intervals. Preovulatory LH and FSH peaks occurred coinciding with the onset o f oestrus in good responding animals instead of a few hours later, as in weakly responding animals or during normal oestrous cycle. PMSG could be still measured in peripheral blood 10 days after application. Preovulatory gonadotropin peaks are preceded in good responding animals by clear oestrogen peaks contrary t o weak responding ones. Progesterone concentrations of good responding animals increase faster after the preouulatory LH peak and reach higher absolute values compared t o bad responding ones or during normal oestrous cycle. Furthermore there was a clear difference in progesterone values between both stimulation methods. Progesterone concentrations after induction of superovulation with PMSG are significantly higher f o r about the same number of corpora lutea as after stimulation with pituitary FSH. For judgement of the success of stimulation the determination of progesterone can be considered as parameter. From the hormonal profiles no conclusion can be drawn why some animals don't respond to the stimulation.     

Colour‐Doppler ultrasound imaging as a laparoscopy substitute to count corpora lutea in superovulated sheep

This study evaluated colour‐Doppler ultrasound imaging (UI) as a substitute for laparoscopy to count the corpora lutea (CL) in superovulated sheep. Twenty‐five Santa Ines ewes were superovulated three times at 21‐day intervals. Corpora lutea were counted by colour‐Doppler UI (CL_DOPPLER) 6 days after each superovulation and confirmed by laparoscopy (CL_LAP) 12 hr later. The mean number of CL was similar for both techniques (2.1 ± 2.5 vs. 2.1 ± 2.7 for CL_DOPPLER and CL_LAP, respectively) with a significant positive correlation (r = .94; r²=.89). Colour‐Doppler UI effectively evaluated the ovarian response in superovulated ewes and efficiently identified animals that did not respond to superovulation.     

Techniques and success of embryo transfers in Angora goats

Thirty-five mixed-age Angora does were subjected to superovulation and oestrous synchronization and of the 34 which were subsequently entire mated, 33 were subjected to surgical egg recovery approximately five days after oestrus. These 33 donors averaged 8.8 ovulations and 2.5 large (>5 mm) follicles. All corpora lutea in six donors were undergoing premature regression. The average donor egg recovery rate, egg fertilization rate and percent of eggs transferable was 82,87 and 81%, respectively, giving 6.8 eggs, 6.0 embryos and 5.5 transferable embryos per donor. Egg recovery was reduced dramatically when premature regressing corpora lutea were present. Recipient feral does were synchronized and 183 embryos transferred surgically to 133 recipients. Eighty-eight (66%) of the recipients kidded producing 118 kids (64% embryo survival). The 35 potential donors produced 36 kids from their natural mating which occurred shortly after surgery. Thus the donors produced a total of 154 kids from embryo transfer and natural mating, an average of 4.4 kids/doe/breeding season. This rate of reproduction is four to five times faster than normal and confirms that the technique achieves its objective of rapidly increasing the number of offspring from selected animals.     

Techniques and success of embryo transfers in Angora goats

Thirty-five mixed-age Angora does were subjected to superovulation and oestrous synchronization and of the 34 which were subsequently entire mated, 33 were subjected to surgical egg recovery approximately five days after oestrus. These 33 donors averaged 8.8 ovulations and 2.5 large (>5 mm) follicles. All corpora lutea in six donors were undergoing premature regression. The average donor egg recovery rate, egg fertilization rate and percent of eggs transferable was 82, 87 and 81%, respectively, giving 6.8 eggs, 6.0 embryos and 5.5 transferable embryos per donor. Egg recovery was reduced dramatically when premature regressing corpora lutea were present. Recipient feral does were synchronized and 183 embryos transferred surgically to 133 recipients.

Eighty-eight (66%) of the recipients kidded producing 118 kids (64% embryo survival). The 35 potential donors produced 36 kids from their natural mating which occurred shortly after surgery. Thus the donors produced a total of 154 kids from embryo transfer and natural mating, an average of 4.4 kids/doe/breeding season. This rate of reproduction is four to five times faster than normal and confirms that the technique achieves its objective of rapidly increasing the number of offspring from selected animals.     

Follicullar Development and Embryo Recovery Following 3 versus 8 FSH Injections in Heifers

Ovarian follicular dynamics and embryo yield were studied during 2 different FSH regimens for superovulation of cattle. Twenty heifers were given intramuscular injections of FSH (total of 35 mg NIH) either once daily for 3 days (Group 3×1) or twice daily for 4 days (Group 4×2). At 72 h after the first FSH injection, each animal was injected with 0.75 mg cloprostenol. Inseminations were performed at 12 h and 24 h after the onset of heat. Transrectal ultrasonography was performed on the day of the first FSH injection, the day of cloprostenol injection, the day of insemination and finally on the day of embryo recovery (day 6 or 7 after heat). The numbers of small (2–4 mm), medium (5–9 mm) and large (>10 mm) size follicles were recorded. The total number of corpora lutea, eggs and transferable embryos were recorded on the day of embryo recovery. No differences were found between the 2 groups in either of the parameters studied (p>0.05). It can be concluded that treatment with this FSH preparation once daily for 3 days gives a folliculogenic and superovulatory response similar to a treatment regimen where it is given twice daily for 4 days.     

Effect of human chorionic gonadotropin on induced ovine corpora lutea during the anestrous season

Experiments were conducted to determine the effect of additional gonadotropic support on induced corpora lutea of anestrous ewes. In one series of experiments, ewes were superovulated and half the ewes received an i.v. injection of 500 IU human chorionic gonadotropin (hCG) on day 5 after ovulation. Corpora lutea were collected from both groups on day 10 after ovulation. Dissociated corpora lutea collected from ewes which received additional hCG contained proportionately more large luteal cells than did those from control ewes (P<.05). In neither cell type was content of receptors for luteinizing hormone (LH) or secretion of progesterone in response to LH affected by an additional injection of hCG. Large cells from anestrous ewes produced more progesterone in response to LH (P<.05) than did large cells from similarly treated ewes during the breeding season. Small cells collected during either season responded similarly to LH. In another series of experiments, anestrous ewes were induced to ovulate and were exposed to fertile rams. Half the ewes received an i.v. injection of 500 IU hCG on day 5 after ovulation. Serum content of progesterone was higher on day 10 in ewes which received hCG 5 days earlier than in control ewes, although progesterone levels declined to generally nondetectable levels in nonpregnant ewes of both groups by day 16. Pregnancy rates in the two groups were not different. We concluded that additional gonadotropic support affects the morphology and function of corpora lutea from anestrous ewes and may be useful for enhancing fertility during the nonbreeding season.     

Effects of prostaglandin F2 alpha on degranulation of bovine luteal cells on days 4 and 12 of the estrous cycle

Corpora lutea were collected from 18 beef heifers on day 4 or 12 of the estrous cycle, 1 hour after prostaglandin (PG) F2 alpha or saline (control) treatment. Five heifers also were treated with PGF2 alpha on day 4, but their corpora lutea were not collected until day 12. The relative percentage of cytoplasm occupied by granules decreased only in large luteal cells (LLC) in heifers given PGF2 alpha on day 12, compared with the percentage in controls. Small luteal cells (SLC) were not as affected. The luteal concentration of progesterone was similarly decreased only in heifers given PGF2 alpha on day 12. Treatment of heifers with PGF2 alpha on day 4 had no marked effect on progesterone values or on the relative percentage of cytoplasm occupied by granules in LLC or SLC. Seemingly, LLC were more responsive to PGF2 alpha than were SLC, and PGF2 alpha treatment of beef heifers at day 4 did not markedly impair luteal function.     

Plasma progesterone, metabolic hormones and beta-hydroxybutyrate in Holstein-Friesian cows after superovulation

Metabolic hormones [insulin, leptin, insulin-like growth factor-I (IGF-I), thyroxine (T4) and triiodothyronine (T3)], progesterone (P4) and beta-hydroxybutyrate (BHB) serum concentrations were evaluated and their effect on the superovulation results of donor cows was investigated in a semi-arid environment. Body weight, body condition score (BCS) and lactation stage were also included in the analysis. Twenty-three Holstein-Friesian cows were superovulated with 600 IU FSHp following the routine procedure and flushed on day 7 in a Multiple Ovulation and Embryo Transfer Centre in the semi-arid area of Brazil. The corpora lutea (CL) were counted and blood samples were collected for assays. All of the hormones investigated and BHB serum concentrations were within the physiological ranges. There was a positive correlation between hormones, except between BHB and all the others. The leptin level was influenced by feeding status, as indicated by the BCS. Insulin, T4, T3 and BHB levels were affected by milking status. Dry cows had higher levels of all hormones except BHB. An optimum level of leptin resulted in the highest number of CL, while the linear increase of P4, T4 and IGF significantly increased the number of CL.     

Non Cat-Like Ovarian Cycle in the Eurasian and the Iberian Lynx – Ultrasonographical and Endocrinological Analysis

The Iberian lynx is considered the most endangered felid species. Therefore, an ex situ conservation program was initiated to protect this species from extinction. Additional knowledge on lynx reproduction biology and reliable methods for reproductive monitoring are important for developing a captive breeding program. The aim of this study in lynx was to implement transrectal ultrasonography to visualize ovarian structures (follicles, corpora lutea) and to assess ovarian activity in addition to analysis of serum progesterone and oestradiol. Because of limited access to Iberian lynxes, the less-endangered Eurasian lynx and bobcat were also studied in this comparative study. Recent endocrinological studies based on faecal and urinary progesterone and oestrogen metabolites revealed that steroid profiles in both these species were alike and did not follow the typical pattern of other felids. Pregnancy diagnosis was not possible, since progesterone concentrations did not differ between pregnant and pseudopregnant animals. Progesterone was also detected after parturition as well as after weaning until the onset of a new oestrous cycle. In the present study, the presence of corpora lutea during the non-breeding season was confirmed by ultrasonography and by elevated serum levels of progesterone averaging 3.56 ± 1.3 ng/ml in Eurasian and 6.1 ± 0.26 ng/ml in Iberian lynx, respectively. The ultrasonographical findings on the ovarian structures suggest strongly that corpora lutea developed after ovulation stay active until November and regress before the onset of the next oestrus.     

Relationship between different concentrations of the plasma progesterone at the time of FSH-P treatment and the superovulatory response in Holstein dairy heifers

The aim of this study was to evaluate the influence of two different concentrations of plasma progesterone at the time of FSH-P treatment on the superovulatory response in dairy heifers. Sixteen reproductively sound Holstein heifers (13-15 months of age) were used in this study. Superovulatory treatment was commenced at mid-dioestrus (Day 10 ± 2 of the oestrous cycle) of the synchronized (using two injections of PGF2α, 11 days apart) oestrous cycles. Blood samples were collected on the day and the day after commencing FSH-P treatment and at oestrus for plasma progesterone determination. Heifers were grouped based on two levels of plasma progesterone; Group low progesterone (LP; ranging from 2 to 4.5 ng /ml; n = 7) and Group high progesterone (HP; ≥ 4.6 ng /ml; n = 8) at the beginning of FSH-P treatment (one heifer was excluded from the statistical analysis because of the abnormal progesterone level at oestrus). The superovulatory response in terms of mean numbers of palpable corpora lutea (ovulation rate) was significantly higher (p < 0.05) in group LP than group HP. Ovulation rate was negatively correlated (r = -0.51) with the progesterone concentration at the time of commencing FSH-P treatment (p < 0.05). Data suggest that varying concentrations of plasma progesterone at the time of FSH-P treatment may have a different effect on the outcome of superovulatory response in dairy heifers.     

拴系饲养与自由采食对西门塔尔青年母牛超排效果的影响

本文分析比较了2009和2010年两种不同饲养管理方式对102头西门塔尔青年母牛超排效果的影响。结果表明，2009年拴系饲养的供体牛超排效果明显好于2010年自由采食的供体牛，平均回收卵和有效胚胎分别为15．04枚、13．65枚，8．51枚、6．93枚。2009年的有效胚胎率（56．58％）也高于2010年（50．73％）。从胚胎发育阶段的比例来看，2010年供体牛的扩张囊胚和囊胚比例比2009年低，而未受精和退化胚胎比例较高。结果显示，青年母牛长期处于营养摄入量不足的情况下，不仅影响体成熟，还会降低母牛的繁殖机能和超排效果以及有效胚胎数。     

Procedure for successful interspecific embryo transfer from mouflon (Ovis gmelini musimon) to Spanish Merino sheep (Ovis aries).

Embryos from five anesthetized mouflons (Ovis gmelini musimon), superovulated with FSH-o (Ovagen) were transferred into preselected Spanish Merino sheep (Ovis aries). Myorelaxation was complete in four of five donor mouflons. The status of the uterus of potential recipients was evaluated by transrectal ultrasonography, and those ewes with fluid in the uterine horn were rejected. The corpus luteum in each ewe was assessed ultrasonographically the day before surgery. Plasma progesterone levels and the quality of the corpora lutea were the criteria for selection of recipients. Ten embryos were transferred to the five selected Spanish Merino recipients, resulting in four pregnancies and seven live-born lambs, including three sets of twins. This study shows that determination of plasma progesterone levels combined with ultrasonographic assessment of the corpus luteum provides information useful for screening of potential recipients.     

Follicle dynamics and characteristics of ovulation in heifers after Ovsynch treatment in the last third of the estrous cycle

The objective of the experiment was to study follicular dynamics and characteristics of ovulations in dairy heifers after application of the Ovsynch protocol in the last third of estrous cycle. Therefore, altogether 27 regular cycling Holstein heifers were given an injection of GnRH on day 14, 16 or 18 (9 heifers each in group 1 to 3) of the estrous cycle. All heifers were administered PGF2alpha seven days later. Blood was collected for progesterone determination, just before, 24 hours and 48 hours after the PGF2alpha injection. A second injection of GnRH was administered 48 hours after the PGF2alpha injection. Ovarian follicular dynamics were monitored by frequent ultrasound scanning of the ovaries after first and second GnRH injection. Altogether 22 of 27 heifers (81.5%) ovulated 27 to 33 h after first GnRH injection. In 4 heifers ovulations were recorded 45 to 51 h after first GnRH application. Mean intervals between GnRH application and ovulation were 33.0, 33.6 and 28.3 h, respectively. At the time of PGF2alpha injection mean progesterone concentrations were similar in groups 1 and 2, but significantly lower than in group 3. After the second GnRH treatment 5,6 and 8 heifers had ovulations.The average intervals from the second GnRH treatment to ovulation were 24.8, 24.0 and 24.4 h respectively.The results show that Ovsynch is not sufficient to ensure synchronisation of oestrous and ovulation in each animal treated.     

Ovarian lesions induced in heifers by intravenous inoculation with modified-live infectious bovine rhinotracheitis virus on the day after breeding

Four commercially available vaccine strains of modified-live infectious bovine rhinotracheitis virus were passaged once in embryonic bovine kidney cells. Heifers were inoculated IV on the day after breeding with 5.0 ml of nondiluted cell culture fluid of each of the 4 strains. Virus was reisolated from nasal swabs and blood collected during the week after inoculation. The heifers were killed 9 to 14 days after inoculation. Mild-to-marked inflammatory and necrotic lesions were seen in the corpora lutea and ovaries of the heifers. The lesions were similar to, and almost as severe as, those resulting from the inoculation of virulent strains of infectious bovine rhinotracheitis virus. Adrenal lesions were also found in all heifers examined. Virus was reisolated from the ovaries of only 4 of the 8 heifers. However, virus was confirmed in the ovaries of all 8 heifers, using immunofluorescent or ultrastructural studies. Heifers with severe luteal damage had abnormally low plasma progesterone concentrations.     

Plasma progesterone assays in superovulated cattle

Plasma progesterone was measured in 14 normally cycling heifers and cows subjected to non-surgical recoveries of embryos. A radioimmunoassay (RIA) method was used for progesterone determination. The average progesterone concentration increased from 7.5 to 11.6 ng/ml in 8 of the animals following treatment with PMSG on day 8–12. Six animals had a decrease from 5.0 ± 2.1 to 3.9 ± 2.5 ng/ml. The overall increase was from 6.4 ± 2.7 ng/ml to 8.3 ± 4.8 ng/ ml. Prostaglandin F2a-analogue (cloprostenol) treatment resulted in a sharp decrease in plasma progesterone followed by a rapid increase to an average of 46.8 ng/ml on day 16. A high degree of variability in this peak value was observed, and it was not correlated with the number of corpora lutea. The superovulatory cycle was generally prolonged. The heat following the superovulatory treatment was silent, and a typical ovarian resting period was observed during which the progesterone concentration remained low and the ovaries small.