411 EFFICIENCY OF DAY SEVEN COLLECTION OF BOVINE EMBRYOS AFTER SUPEROVULATION BY FLUSHING THE OVIDUCTS AND THE UTERINE HORNS

2010 ◽  
Vol 22 (1) ◽  
pp. 363
Author(s):  
V. Havlicek ◽  
A. Kuzmany ◽  
J. F. Beckers ◽  
B. Remy ◽  
G. Brem ◽  
...  

Embryo collection on Day 7 following superovulation is characterized by wide variation in the number of ova/embryos recovered. The differences between the numbers of corpora lutea and recovered ova/embryos provide evidence for incomplete recovery. The aim of this study was to examine the effect of flushing only the uterine horns v. endoscopical flushing of both the oviducts and the uterine horns on embryo recovery rates. A total of 12 superovulated Simmental heifers, aged 18 to 24 months were presynchronized by i.m. administration of PGF2 (500 μg of cloprostenol; Estrumate®, Essex Tierarznei, Munich, Germany) twice within 11 days. Two days after each of the PGF2 treatments, the animals received 0.02 μg of GnRH (Receptal®, Intervet, Boxmeer, the Netherlands). Between Days 9 and 11 of the estrous cycle, the animals got the first of 8 consecutive, twice-daily FSH injections in decreasing doses (in total 300-400 mg of FSH equivalent according to body weight; Stimufol®, ULg FMV PhR, Tilman, Belgium). Two PGF2 treatments were administered 60 and 72 h after the initial FSH treatment. Finally, 48 h after the first PGF2 application, ovulation was induced by injecting 0.02 μg of GnRH simultaneously with the AI. The AI was performed by using 1 straw of semen from a Simmental bull of proven fertility. Seven days after estrus, the heifers were restrained and an epidural anesthesia was performed. The uterine horns of the heifers were first flushed nonsurgically (300 mL of PBS + 1% FCS). Additionally, the oviducts were flushed by a transvaginal endoscopic technique (50 mL of PBS+1% FCS) followed by repeated flushing (250 mL of PBS + 1% FCS) of the uterine horns (combined flushing). In total, 12 animals delivered 132 ova/embryos (mean = 11 ± 6.5; recovery rate = 83%), with 83 developed to blastocysts/morulae (mean = 6.9 ± 6.4). The first flush of the uterine horns gave 3.8 ova/embryos on average with 2.8 being blastocysts/morulae (developmental rate = 75.6%). The following combined flush gave 7.3 ova/embryos with 4.1 developed to blastocysts/morulae (developmental rate = 56.3%). No differences were found between flushing the left and right sides. In conclusion, the present study shows that the additional step involving flushing of oviducts plus uterine horns of superovulated heifers provided recovery of a higher number of ova/embryos. It is assumed that these extra numbers might be caused by the flushing of (1) the uterine horns repeatedly, (2) the region of the utero-tubal junctions, and (3) ova/embryos from the oviducts, probably as a result of incomplete migration.

2014 ◽  
Vol 26 (1) ◽  
pp. 168
Author(s):  
H. W. Vivanco-Mackie ◽  
M. D. Ponce Salazar ◽  
M. M. Gonzales ◽  
M. A. Tapia

Alpacas are induced ovulators, responding to copulation and (or) exogenous application of ovulation-inducing hormones. The objective of this study was to determine the efficiency of the injection of a gonadotropin-releasing hormone (GnRH) agonist versus LH in the induction of ovulation and the presence and size of non-ovulated follicles at the time of embryo collection and its relationship to the yield of transferable embryos in superovulated alpacas. Twenty-one adult (3 to 7 years old) female alpacas under extensive grazing at 4300 m elevation in the Peruvian Andes that had been synchronized and treated for superovulation were induced to ovulate 6 days after the application of the superovulatory hormone (1000 IU of eCG, Folligon®, Intervet International BV, Boxmeer, the Netherlands) by mating with fertile males and injection immediately after copulation of either an IM dose of 0.0084 mg of buserelin acetate (Buserelina Zoovet®, Laboratorio Zoovet, Santa Fe, Argentina) to 10 alpacas (T1) or an IM dose of 5-mg Armour standard of LH (Lutropin®, Bioniche Animal Health, Belleville, ON, Canada) to 11 alpacas (T2). All alpacas had a second mating 12 h after the first mating and were subjected to ovarian inspection by ultrasonography and previous embryo collection by nonsurgical transcervical embryo flushing 6.5 days after the first mating. On average, the embryo recovery rate for T1 was 34.6% and there were 7.8 ± 3.99 corpora lutea (CL), 2.7 ± 4.08 collected embryos, and 3.6 ± 2.95 total, 0.5 ± 0.85 small (<6 mm), 1.8 ± 1.99 medium (≥6 but ≤14 mm), and 1.3 ± 2.11 large (≥15 mm) non-ovulated follicles. For T2, the embryo recovery rate was 59.4% and there were 6.73 ± 1.49 CL, 4.0 ± 2.57 collected embryos, and 0.64 ± 0.81 total, 0.0 ± 0.0 small, 0.36 ± 0.67 medium, and 0.27 ± 0.47 large non-ovulated follicles. The differences between treatments were nonsignificant (P > 0.05) for all the parameters; however, there was a clear tendency for a better recovery rate, more embryos collected, and lower number of non-ovulated follicles in T2. The Pearson correlation coefficient between the presence of large follicles in the ovaries at the time of embryo collection and the total number of embryos collected was negative (r = –0.26) and highly significant (P ≤ 0.001). The use of LH for ovulation induction of superovulated alpacas seems to be more advisable than the use of GnRH agonist; further comparisons with larger number of observations per treatment are recommended. This study was financed by the Peruvian Fund for Innovation, Science and Technology (FINCYT).


2010 ◽  
Vol 22 (1) ◽  
pp. 360
Author(s):  
M. I. Cueto ◽  
F. Pereyra-Bonnet ◽  
P. Silvestre ◽  
A. E. Gibbons

The aim of the study was to assess possible variations in superovulatory yields due to different FSH treatments at 2 times of the year. Superovulation and embryo recovery were performed during the breeding (n = 63) andnonbreeding (n = 46) seasons in Merino ewes located at 41°S latitude. Animals were kept under the same conditions, housed outdoors in a sheltered and covered pen, and were fed a liveweight maintenance ration. All animals received 60-mg medroxyprogesterone acetate intravaginal sponges (Progespon®, Syntex, Buenos Aires, Argentina) for 14 days. Ewes were then randomly assigned to 2 different superovulatory treatments: classic (n = 74) and one shot (n = 35) in both seasons. Classic superovulatory treatment consisted of 7 decreasing doses (2 × 48 mg, 2 × 24 mg, 2 × 20 mg, and1 × 16 mg NIH-FSH-P1)ofFSH (Folltropin®-V, Bioniche, Belleville, Ontario, Canada), administered twice daily from 48 h before to 24 h after pessary removal. A dose of eCG (300 IU; Novormon®, Syntex) was administered at progestagen removal. One shot superovulatory treatment consisted of a single dose of FSH (70 mg NIH-FSH-P1) plus 300 UI of eCG injected at pessary withdrawal. Embryo donors were inseminated by laparoscopy with frozen-thawed semen (100 × 106 spz) 12 h after the onset of estrus. Surgical embryo recovery was done on Day 7 after sponge withdrawal and embryos were graded for quality according to morphology (Grade 1 = excellent or good; Grade 2 = fair; Grade 3 = poor; and Grade 4 = dead or degenerated; IETS 1998). A 2 × 2 factorial ANOVA was used to test the main effects (season and superovulatory treatment) and interactions. There were no significant differences in the proportion of responding ewes (>3 corpora lutea), ovulation rate, and recovered Grades 1 to 2 embryos between the breeding and nonbreeding season (Table 1; P > 0.05). However, number of recovered ova/embryos and ova/embryo recovery rate were higher during the breeding season compared with the nonbreeding season, whereas the percentage of nonfertilized ova was lower in the breeding season than in the nonbreeding season (P < 0.05). Analysis of data comparing superovulatory treatments showed that the proportion of responding ewes, ovulation rate, recovered embryos, and recovered Grades 1 to 2 embryos were lower for the one shot treatment than for the classic treatment (P < 0.05). Embryo recovery rate and nonfertilization rate did not differ between treatments (P > 0.05). It was concluded that there was an increase in the number of total recovered ova/embryos during the breeding season compared with the nonbreeding season, although the number of recovered good-quality embryos was not affected. The use of multiple FSH injections produced a higher number of total recovered and viable embryos in Merino sheep than the one shot superovulatory treatment. Table 1.Embryo yields in ewes submitted to superovulation


2014 ◽  
Vol 54 (10) ◽  
pp. 1605 ◽  
Author(s):  
B. F. Zohara ◽  
Azizunnesa ◽  
M. F. Islam ◽  
M. G. S. Alam ◽  
F. Y. Bari

The effects of two doses of cloprostenol and two doses of flurogestone acetate sponge on the onset of oestrus, and embryo recovery and quality were evaluated. Thirty-two indigenous ewes (Wera breed) were allocated into four groups of eight. All ewes were synchronised with 100 µg (Group I) or 175 µg (Group II) cloprostenol injection, 9 days apart, or insertion of intravaginal sponges containing 30 mg (Group III) or 45 mg (Group IV) flurogestone acetate (FGA) for 12 days. The ewes were superovulated with 600 IU PMSG intramuscularly 10 days after the second cloprostenol injection or immediately after sponge removal on Day 12. After the detection of oestrus, the ewes were mated naturally at 6 and 12 h, and some ewes were inseminated laparoscopically. Embryos were recovered surgically 5 or 6 days after service. All ewes exhibited oestrus. The onset of oestrus occurred significantly (P < 0.05) earlier in FGA-treated (50.0 ± 1.5 and 48.0 ± 0.00 h) than in cloprostenol-treated groups. There were no significant differences (P > 0.05) in the mean time of onset of oestrus (50.0 ± 1.5 and 48.0 ± 0.00 h) between the two doses of cloprostenol. The mean number of corpora lutea (8.1 ± 1.26) and embryos recovered (6.1 ± 1.00) was significantly (P < 0.05) higher in ewes treated with 45 mg FGA than in ewes treated with cloprostenol. Embryo recovery rate was significantly (P < 0.05) higher in ewes treated with 45 mg FGA (75.4%) than in other groups (41.7% and 51.6% in 100 μg and 175 μg cloprostenol- and 52.7% in 30 mg FGA-treated groups, respectively). Fertilisation rate was 93.3% in ewes given 100 µg cloprostenol, whereas other groups showed 100% fertilisation rate. The highest percentage (100%) of Grade 1 embryos was in FGA groups. In conclusion, despite FGA protocol presenting superior results, cloprostenol protocol was equally efficient in synchronising oestrus. The embryo recovery rate was better after 45 mg FGA than 30 mg FGA or after either dose of cloprostenol.


2005 ◽  
Vol 17 (2) ◽  
pp. 225 ◽  
Author(s):  
M. Schmidt ◽  
B. Avery ◽  
T. Greve

For stem cell production and detailed morphological analysis 12–14-day-old bovine embryos are suitable. However, it has been proven to be difficult to extend the in vitro culture period beyond Days 8–9, and it was the aim of the present experiment to examine whether it might be possible to culture 6–7-day-old in vitro-produced (IVP) embryos for a period of 5–7 days in the uterine horns of heifers. The IVP embryos were produced by standard procedures. Briefly, IVM took place in DMEM medium supplemented with 5% serum, EGF, and eCG/hCG, and IVF was carried out in TALP medium under 5% CO2 in humidified air and at 38.5°C. IVC took place in SOFaaci supplemented with 10% serum under 5% CO2, 5% O2 and 90% N2 at 38.5°C .The embryos were cultured in vitro to Days 6–7 post insemination, when morulas and blastocysts of excellent quality were placed in HEPES-buffered TCM199 with 10% serum, loaded in numbers of 10–30 into 0.25 mL straws, and then transported to the place of transfer in a portable incubator at 38.5°C. The embryos were transferred nonsurgically to the mid or distal part of the uterine horns of 28 dairy heifers which were heat synchronized with injections of cloprostenol (Estrumat Vet, Schering-Plough, Farum, Denmark) to a cycle stage of embryo age +1 day. In 16 heifers, embryos were transferred into both sides and for the remaining ones only into the horn ipsilateral to the ovary bearing the corpus luteum. After 5–7 days, the heifers were flushed nonsurgically by standard method, using a flushing catheter of large caliber (Minitab® 18 G) and slow infusion and evacuation of the fluid. The differences in recovering rate among horns were identified by Fisher's Exact test. Data are given as LS means ± SEM values and statistical differences assigned at the P < 0.05 level. In 6 of the 28 heifers no embryos were obtained; in these 6 cases, the quality of the transferred embryos, the transfer procedure, the heifers, and the flushing procedures did not differ in any obvious way from those of the successful flushings, which numbered 22 (79%). The mean embryo recovery rate was 40 ± 3% with a variation from 7% to 93%. There was a minor but not statistically significant difference between the overall recovery rate of embryos from the ipsi- versus contralateral horn, respectively (44 ± 5% vs. 38 ± 6%). In only 4 of the 16 heifers where transfer occurred to both horns was the recovery rate higher in contralateral side, compared to 9 heifers where the highest recovery rate was seen in the ipsilateral side. The oldest elongated embryos were in one occasion damaged and in another tangled, making it difficult to isolate the individual embryo; apart from that, all of the embryos seemed of excellent quality making it possible to isolate the embryonic discs. It can be concluded that it is possible to culture in vitro produced Day 6–7 bovine blastocysts in the uterus of synchronized heifers and to achieve an acceptable recovery of Day 12–14 embryos.


2015 ◽  
Vol 27 (1) ◽  
pp. 168
Author(s):  
K. Karakas ◽  
H. Alkan ◽  
G. Onur ◽  
D. Ozen ◽  
M. Kaymaz ◽  
...  

The aims of this study were to compare the embryo recovery rate in Angora goats based on application timing; at the beginning (September – October; Group 1) and end (December; Group 2) of the breeding season and to evaluate the viability and survivability of fresh or vitrified-thawed embryos when transferred. For this purpose, nine Angora goats were used as donors and thirthy Angora goats were used as recipients. Donor goats were synchronized and superovulated with traditional protocol and were mated with fertile bucks. At the 156th hour of the mating, embryos were collected surgically and evaluated under a stereo microscope. In group 1, 103 embryos and in group 2, 63 embryos were collected from nine goats. Fresh or vitrified-thawed embryos were transferred surgically to synchronized recipients. In Group 1 fresh/thawed embryos were transferred to 15/15 goats and in group 2, fresh/thawed embryos were transferred to 8/8 goats, respectively. Each recipient received 1 or 2 embryos ipsilateral to the ovary containing one or more corpora lutea. On day 30 of the transfer, goats were examined by transrectal ultrasonography, pregnancy rates of fresh/thawed embryos were 66.6%/26.6% for group 1 and 62.5%/62.5% for group 2. On day 100 of the transfer, goats were examined again by ultrasonography, and pregnancy rates were 46.6%/0% for group 1 and 37.5%/0% for group 2, respectively. After about 50 days, goats were kidded. In group 1, 3 twins and 4 single kids were born; in group 2, 2 twins were born. The total number of collected embryos and pregnancy rates among the groups were analysed using SPSS® (version 14.01, Chicago, IL, USA) and for all comparisons, differences were considered with a minimum of 5% significance level. After statistical analyses, the numbers of collected embryos at the beginning and at the end of the breeding season were compared. There was no difference in freezable/transferable embryo quality. As a result, embryos could be collected after superovulation protocols in Angora goats both at beginning and end of the breeding season, however there might be a decrease in numbers of collected embryos and the reasons for this might not be only the seasonal factors but also the environment, care, nutrition and previous superovulation protocols. The pregnancy rate following transfer of fresh embryos was satisfactory but not all does confirmed pregnant kidded; hence, reducing the number of recipients kidding. The pregnancy rate following transfer of vitrified-thawed embryos was generally low and unsatisfactory. Further research is warrented in improving the cryopreservation techniques and thus the embryo survival rate of Angora goat embryos. This study was financed with the University of Ankara Grant.


2009 ◽  
Vol 21 (1) ◽  
pp. 153 ◽  
Author(s):  
E. Østrup ◽  
M. Vejlsted ◽  
M. B. Nielsen ◽  
M. T. Madsen ◽  
P. Maddox-Hyttel

It is generally accepted that 30% of the embryos in a porcine litter die within the first 40 days of pregnancy (Pope WP and First NL 1985 Theriogenology 23, 91–105). The aim of the study was to investigate the dynamics of embryonic mortality from the 2nd to the 7th week of pregnancy in a homogeneous pig population in order to test whether this dogma holds true. A total of 141 pregnant Danish Landrace × Yorkshire gilts were divided into three groups dependent on gestational length: Group 1 (Days 9 to 24 post insemination (p.i.)): At Days 9 to 18 p.i., embryos were collected by flushing the uterine horns with PBS containing 1% serum. At Days 19 to 24, embryos were identified in situ by opening of the horns along the anti-mesometrial side. All embryos were staged according to the morphological appearance of embryo proper. Pre-somite stage embryos were categorized as either: Hatched blastocysts, pre-streak 1, pre-streak 2, primitive streak, or neural groove stage embryos (Vejlsted M et al. 2006 Mol. Reprod. Dev. 73, 709–718). Somite stage embryos were staged according to the number of somites. All embryos in Group 2 (Days 24.5 to 33 p.i.) and Group 3 (Days 40.5 to 47 p.i.) were identified in situ by opening the uterine horns as described above. The localization in the uterus and the Crown Rump Length (CRL) was recorded for all embryos in these groups. The average embryo recovery rate, (i.e. the ratio between the numbers of recovered embryos and the CL numbers) was 82%. Moreover, there were no significant differences between the groups with respect to the embryo recovery rate, signaling the absence of continued embryonic mortality. No significant correlations were obtained between the location of the embryos in the uterus and the CRL (only measured for Groups 2 and 3). Our data indicate that (1) the level of embryonic mortality was less than 10 to 15% and (2) there was no continued embryonic mortality occurring between Days 9 to 47 p.i. This is in great contrast to previous reports. Furthermore, there is no evidence that the location in the uterine horn has any influence on the embryonic development. Table 1.The average numbers of corpora lutea (CL), embryos, and the embryo recovery rates in gilts at different time points after insemination The Danish Research Council for Technology and Production Sciences.


2021 ◽  
Vol 33 (2) ◽  
pp. 182
Author(s):  
M. Hussain ◽  
K. Ahmed ◽  
P. Chakravarty ◽  
V. Paul ◽  
B. C. Deka ◽  
...  

The Arunachali breed of yak is reared by the Monpa pastoral community of Arunachal Pradesh in India for their livelihood and nutritional security on highland pastures. In addition to fulfilling the basic needs of highlanders, this animal is associated with poor production potential linked to its inherent reproductive problems, including silent oestrus, seasonality, and inbreeding, making yak rearing a less-profitable venture. In the recent past, efforts have been made to improve reproductive efficiency of Arunachali yak through assisted reproductive techniques. However, a few regimens for superovulation have been tried to date with limited success in terms of superovulatory response and embryo recovery. Therefore, the present study was undertaken to evaluate the efficacy of two different doses and regimes of superovulation: Stimufol (400 and 200µg per animal) and Folligon (1500 and 1000IU per animal) in Arunachali yak. Twenty-four yaks were allotted in 4 groups (of 6 animals each) and subjected to respective superovulation treatment. Thereafter, the treatment response was assessed in terms of expression of oestrus, interval between treatment and oestrus onset, duration of oestrous, number of corpora lutea and embryos recovered, and analysed using two-way statistical analysis between treatment groups. The results (Table 1) showed a significant (P&lt;0.01) variation in onset of oestrus after the treatment, whereas other responses did not differ among the groups. Further, the recovered embryos were categorized as excellent, good, fair, and poor according to cell size, shape, texture, and number of vesicles present in the blastomeres; 58.33, 20.83, 8.33, and 12.5% embryos in these categories were recovered, respectively. The overall embryo recovery rate was 30.77%, ranging from 10.53 to 52.38% in different treatment groups. The numbers of embryos recorded were less than the numbers of CL present, showing the possibility of non-availability of all ovulated oocytes for fertilization in the oviduct due to untrapping by the fimbriae. The effectiveness of treatments depended upon the precision of oestrus detection and the time of ovulation. In our study, the variation in onset of oestrus might be associated with poor expression of behavioural oestrus in the treated animals. Based on the present findings, we conclude that all the treatments are effective in superovulation and embryo recovery. However, the use of Folligon at 1500IU seemed to be comparatively more effective in Arunachali yak. Table 1. Mean (n=6) average of treatment responses in yak following different superovulatory treatment Variable Treatment Stimufol Folligon 400 µg/animal 200 µg/animal 1500 IU/animal 1000 IU/animal Oestrus response (%) 100 100 100 100 Interval between treatment and oestrus onset (h) 17.67±0.56a 20.83±0.79b 21.17±0.79bc 23.67±1.43c Duration of oestrous (h) 30.33±1.09 28.50±0.99 31.50±1.50 28.83±1.25 Corpora lutea (n) 2.83±1.22 3.50±1.18 3.50±0.67 3.17±0.87 Embryo recovered (n) 0.83±0.83 1.00±0.81 1.83±0.98 0.33±0.21 Recovery rate (%) 29.41 28.57 52.38 10.53 a–cMeans within a row with different superscripts differ P&lt;0.05.


2004 ◽  
Vol 47 (6) ◽  
pp. 585-594 ◽  
Author(s):  
K.-P. Brüssow ◽  
I. Egerszegi ◽  
J. Rátky ◽  
F. Soós ◽  
P. Garcia Casado ◽  
...  

Abstract. Since the morphology of the reproductive organs could be a wherefore of reproductive performance of Mangalica, this study was conducted to get some more information about the number of corpora lutea and the size of reproductive tract both in cycling and pregnant Mangalica pigs. Two experiments were carried out to investigate the reproductive tract of Mangalica gilts. In Experiment 1, reproductive organs of 66 gilts (12–15 month of age) were recovered immediately after slaughter to determine the number of ovarian features, the weight and diameter of the ovaries, and the weight and length of oviducts and uteri, respectively. In Experiment 2, 22 puberal Mangalica (M) gilts and 34 German Landrace (L) gilts were used following estrus synchronization and artificial insemination. Genital tracts were recovered by ovario-hysterectomy on day 1 (n = 8 M; 10 L), day 12 (n = 8 M; 22 L) and day 24 (n = 6 M; 2 L) of pregnancy and the number of corpora lutea, ovarian weight and diameter, and the weight and length of oviducts and uteri evaluated. Oviducts and uterine horns (day 1 and 12, respectively) were flushed or uterine horns were opened (day 24) for embryo recovery. In Experiment 1, 58 gilts (88 %) were cycling ones with mean number of ovulation of 10.6 ± 3.1. In first estrous gilts (n = 8) it was 11.1± 2.5. No differences were observed both between left and right ovaries, and first estrous and cycling gilts. The number of corpora lutea were correlated with ovarian weight (r = 0.35, p<0.05). Oviduct length (24.4 ± 1.4 and 24.3 ± 0.5 cm) and weight (4.3 ± 0.4 and 3.2 ± 0.2 g), and uterine horn length (143 ± 13 and 143 ± 5 cm) were not different in first estrous and cycling gilts. Uterine weight was higher in first estrous compared to cycling gilts (358 ± 32 vs. 250 ± 12 g, p < 0.05). In pregnant Mangalica (M) and Landrace (L) gilts no breed*day of pregnancy interaction regarding the number of ovulation was found. Mean number of corpora lutea was 17.2 ± 1.2 (M) and 18.6 ± 1.3 (L). Length of uterine horns was reduced in pregnant M compared to L gilts (124 ± 5 vs. 188 ± 6 cm, p < 0.01). Uterus grows in length continuously between day 1 and 24 of pregnancy in Landrace but not in Mangalica sows (p < 0.01). Uterine weight as well increased earlier (day 1 to day 12) in Landrace in comparison to Mangalica (day 12 to day 24). Results of this study support the concept that in Mangalica besides diminished ovarian and oocyte development, uterine conditions, especially growth restricted uterine development, may influence the initial process of early pregnancy and can be another reason of lower fecundity.


2020 ◽  
Vol 60 (4) ◽  
pp. 497 ◽  
Author(s):  
Pedro Henrique Nicolau Pinto ◽  
Mario Felipe Alvarez Balaro ◽  
Helena Fabiana Reis de Almeida Saraiva ◽  
Viviane Lopes Brair ◽  
Vivian Angélico Pereira Alfradique ◽  
...  

Context In vivo embryo production, also called multiple ovulation and embryo transfer, can accelerate genetic gain, and thus improve animal production. However, there are issues limiting a wider use of this biotechnology in sheep livestock. Aims This study aimed to determine (1) whether a previous response to superovulation (SOV) can be used as a criterion to select ewes for in vivo embryo production, (2) whether the intensity of the SOV response (number of corpora lutea, CL) can affect the embryo recovery rate, and (3) whether the number of CL quantified by colour Doppler ultrasonography can be used to calculate the recovery rate. Methods Twenty-five Santa Inês ewes underwent SOV three times (SOV1, SOV2 and SOV3), with 200 mg FSH and natural mating. The number of CL after each SOV was determined by laparoscopy and by colour Doppler ultrasonography. Key results The number of CL significantly decreased (P &lt; 0.05) after SOV1 (7.5 ± 4.8) to 3.0 ± 5.0 at SOV 2 and 2.2 ± 3.5 at SOV3. Strong correlations were observed between SOV2 and SOV3 in terms of numbers of CL (r = 0.86, r2 = 0.74; P &lt; 0.0001) and viable embryos (r = 0.79, r2 = 0.63; P &lt; 00001). However, no correlations were observed between SOV1 and SOV2 or between SOV1 and SOV3. Recovery rate did not differ with the intensity of the SOV response (≤6, 7–10, &gt;10 CL) or between the methods used to quantify CL. Conclusions Ewes did not show the same pattern of response when submitted to successive FSH-based SOV. The intensity of the SOV response did not affect the recovery rate, and the number of CL estimated by colour Doppler ultrasonography can be used to calculate the recovery rate. Implications Selecting sheep embryo donors by a previous SOV response is not always feasible. The recovery rate is homogeneous and it is not affected by the intensity of the SOV response. A nonsurgical technique can be used to assess the recovery rate, improving animal welfare in MOET programs.


1985 ◽  
Vol 107 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
Y. Chabi

ABSTRACT In mink, termination of the delayed implantation period, following reactivation of the corpora lutea, and onset of the spring moult are associated with a rise in prolactin secretion triggered by increasing daylength, while decreasing daylength induces the autumn moult. To establish whether suppression of the function of the pineal rendered the mink unresponsive to daylength changes, the superior cervical ganglion was removed bilaterally 2–4 weeks before mating. Intact and operated females were then left outdoors or were put under a lighting regime of either 15 h light: 9 h darkness (15L: 9D) or 8L: 16D. In July, at the end of the spring moult, the 15L: 9D lighting regime was changed to one of 8L: 16D. Under artificial photoperiods ganglionectomy suppressed the stimulatory role of long days and the inhibitory role of short days on prolactin secretion, and consequently on progesterone secretion and spring moult. Neither was the autumn moult, induced early in intact females by the change to a short photoperiod, advanced in ganglionectomized females, showing that the latter were unresponsive to the artificial modification of the photoperiod. However, in animals kept outdoors, prolactin and progesterone secretion and spring moult were not changed by ganglionectomy. Increase in body weight and autumn moult were only slightly delayed by the operation suggesting that other environmental factors had replaced the synchronizing effect of the daylength changes. Alternatively the desynchronization between intact females responsive to photoperiodism and those rendered unresponsive may be too slow to be observed soon after ganglionectomy. J. Endocr. (1985) 107, 31–39


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