108 COMPARATIVE EFFICIENCY OF GONADOTROPIN-RELEASING HORMONE AND LUTEINIZING HORMONE IN THE INDUCTION OF OVULATION IN SUPEROVULATED ALPACAS

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).

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227 Is the antral follicle count on a random day of the oestrous cycle correlated with superovulatory responses in Santa Inês ewes?

Reproduction Fertility and Development ◽

10.1071/rdv32n2ab227 ◽

2020 ◽

Vol 32 (2) ◽

pp. 241

Author(s):

M. Pupin ◽

G. Vergani ◽

M. Lima ◽

K. Silva ◽

A. Monteiro ◽

...

Keyword(s):

Pearson Correlation ◽

Animal Health ◽

Antral Follicle ◽

Antral Follicle Count ◽

Oestrous Cycle ◽

Corpora Lutea ◽

Embryo Recovery ◽

Flunixin Meglumine ◽

Santa Inês ◽

Synchronization Protocol

Antral follicle count (AFC) performed after an oestrus synchronization protocol has been studied as a tool to select ewes with high potential for invivo embryo production (Pinto et al. 2018 Theriogenology 113, 146-152). However, it would be interesting to know whether AFC assessed on a random day of the oestrous cycle correlates with the superovulatory response. The present study was conducted to evaluate the correlation between AFC at the beginning of progesterone (P4)-based oestrus synchronization protocol used as basis of superovulatory treatment and the number of corpora lutea (CL) 12h before recovery of embryos in Santa Inês ewes. The study was conducted during September and October in northeast Brazil (03°40′26″S and 40°14′20″W) using 8 adult Santa Inês ewes. On a random day of oestrous cycle (Day 0) all ewes received an intravaginal device (CIDR) of progesterone (0.3g, Eazi-breed, Zoetis), which remained for 9 days. On Day 7, the pFSH (133mg, Folltropin V, Vetoquinol) treatment began, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) injected IM at 12-h intervals. On Day 9, 2 equal doses of D-cloprostenol were injected at a 12-h interval (37.5µg, Prolise, Agener União). All ewes showed oestrus and were mated by fertile rams. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was administered IM on Days 12, 13, and 15. On Day 16, non-surgical embryo recovery (NSER) was performed after cervical dilation using D-cloprostenol and oestradiol benzoate at 16h and oxytocin 20min before. Transrectal B-mode ultrasound evaluations (Z5 Vet, Mindray), frequency 7.5MHz, were performed on Day 0 and 7 and 12h before NSER to evaluate the ovarian population present. Pearson correlation analysis (P<0.05) was performed using Bioestat 5.3 software. The number of AFC per ewe at the beginning of the protocol and on Day 7 were 9.9±2.7 and 11±3.2, respectively. The numbers of CL, recovered embryos, and viable embryos were 14.0±3.5, 8.2±10.9, and 6.0±11.0, respectively. There was no correlation of AFC on a random day of oestrous cycle with the number of AFC on Day 7 (P=0.42), number of corpora lutea (P=0.44), number of recovered embryos (P=0.18), or number of viable embryos (P=0.11) in superovulated ewes. In conclusion, we did not find significant correlations between AFC on a random day of oestrous cycle and the superovulatory/embryos response in Santa Inês ewes. Financial support for this study was provided by Embrapa (02.13.06.026.00.02 and 02.13.06.026.00.04) and FAPEMIG (PPM 00201-17).

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225 Evaluation of superovulatory response in Brazilian native sheep by B-mode ultrasonography

Reproduction Fertility and Development ◽

10.1071/rdv32n2ab225 ◽

2020 ◽

Vol 32 (2) ◽

pp. 240

Author(s):

G. B. Vergani ◽

M. S. D. Lima ◽

K. M. Silva ◽

A. W. U. Monteiro ◽

A. F. Ramos ◽

...

Keyword(s):

Recovery Rate ◽

Pearson Correlation ◽

Animal Health ◽

Device Removal ◽

Embryo Recovery ◽

Flunixin Meglumine ◽

Ultrasound Evaluation ◽

Release Device ◽

Linear Probe ◽

Santa Inês

The objective of this study was to evaluate the correlation between the number of corpora lutea (CL), as determined by B-mode ultrasonography, and the total number of structures recovery by non-surgical embryo recovery (NSER) from superovulated ewes. Somali (n=18), Santa Inês (n=18), and Morada Nova (n=16) ewes received an intravaginal device with progesterone (0.33g, controlled internal drug release device, CIDR, Zoetis), which was maintained for 9 days. The superovulatory protocol started 60h before device removal, with 6 decreasing doses (25, 25, 15, 15, 10, and 10%) of p-FSH (IM 133mg, Folltropin V, Vetoquinol) injected every 12h. D-Cloprostenol (IM 37.5μg, Prolise, Agener Union) was injected 12h before and at the moment of device removal. Ewes in oestrus were mated by fertile male rams three times after the onset of oestrus with a 12-h interval. Flunixin meglumine (24.9 mg; Banamine, MSD Animal Health) was injected IM on Days 12, 13, and 15. One day before NSER, B-mode ultrasound evaluations were performed using portable equipment (Z5 Vet, Mindray) with a stiffened multifrequency linear probe to evaluate the number of structures present in the ovaries. Embryo recovery was performed 7 days after progesterone CIDR removal (Day 16). The number of CL and the number of recovered structures were determined and their association evaluated using the Pearson correlation test (P<0.05). Only 17 Somali, 16 Santa Inês, and 15 Morada Nova ewes were submitted to NSER; the other 4 ewes could not be flushed because of low cervical dilation or cervical puncture. After B-mode ultrasound evaluation, 168, 217, and 131 CL were observed, with an average of 9.9 (range: 1 to 12), 13.5 (range: 2 to 47), and 8.7 (range: 3 to 18) CL per donor for Somali, Santa Inês, and Morada Nova ewes, respectively. The recovery rates (i.e. structures recovered by the number of CL counted) were 60.1% (101/168), 96.3% (209/217), and 103.5% (135/131) for the 3 breeds, respectively. There was a positive correlation (r=0.69; P<0.01) between the number of recovered structures and number of CL. Those findings confirm results from other studies, in which the recovery rate varied from 35 to 91%. In some cases, recovery rate can be overestimated because of the difficulty in quantifying CL. In conclusion, B-mode ultrasonography can be used to estimate superovulatory response in ewes and thus as a criterion to decide whether a donor will undergo embryo flushing. Financial support for this study was provided by Embrapa (02.13.06.026.00.04) and Fapemig (CVZ-PPM 00201-17).

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