Mean Ovulation Rate Research Articles

CRISPR/Cas mediated disruption of BMPR-1B gene and introduction of FecB mutation into the Caprine embryos using Easi-CRISPR strategy

Bone Morphogenetic Proteins play a significant role in ovarian physiology and contribute to the reproductive fitness of mammals. The BMPR-1B/FecB mutation, a loss of function mutation increases litter size by 1–2 with each number of mutated alleles in sheep. Considering demand-supply gap of the meat industry, and low replacement rate of indigenous caprine species, the conservative BMPR-1B locus can be explored, and FecB mutated goats can be produced. The experiment one produced CRISPR/Cas mediated KO transferable caprine embryos, and experiment two generated caprine embryos with desired FecB mutation using Easi-CRISPR strategy. In the KO experiment, Cas9 and BMPR-1B guide RNA (100:100ng/ul) were electroporated into single stage caprine zygotes at 750V, 10 ms and 1pulse using Neon transfection system. In the second experiment, phosphorothioate (PS) modified single-stranded oligodeoxynucleotide (ssODN) was used as an HDR template along with CRISPR components (100:100ng/ul, ssODN 100ng/ul). The precise time and method of electroporation, RNP format of CRISPR components and PS modified asymmetric ssODN were the factors that affected the production of mosaicism free BMPR-1B edited caprine embryos. The editing efficiency of KO and KI experiments was 68.52 and 63.16% respectively, and successful production of goats with higher mean ovulation rate can be realized with addition of embryo transfer technology to these experiments.

Lack of Efect of Short-term Lupin Grain Feeding on Ovulation Rate in Non-prolific Polish Mountain Ewes during the Breeding Season: Ultrasonographic and Endoscopic Assessment of Ovarian Activity.

The specific changes in antral follicle numbers and wave-like development have remained unrevealed in cyclic ewes fed high-protein, high-energy lupin grain for 6 days during the luteal phase of the estrous cycle (i.e., short-term nutritional flushing). This study was mainly conducted to determine ovarian effects of the 6-day lupin grain feeding in non-prolific Polish Mountain ewes, using transrectal ovarian ultrasonography and abdominal videoendoscopy. Estrus and ovulations were synchronized in 24 ewes with progestin-releasing intravaginal sponges for 12 days during the middle portion of the breeding season (September-October; 50.0458°N, 19.8406°E). Twenty-four ewes were assigned to three equal groups (n=8 each), including the Control group being fed the maintenance diet (i.e., hay-only), Treatment 1 receiving 500 g of lupin grain once a day, and Treatment 2 receiving 250 g of lupin grain twice a day, from days 9-14 of the synchronized estrous cycle (day 0=first ovulation of the interovulatory period studied). No differences were observed in the mean ovulation rate among the three groups of Polish Mountain ewes (P>0.05). Ovarian antral follicles emerging in the penultimate wave of the estrous cycle in Treatment 2 ewes had a longer growth phase (p <0.05) and attained a greater diameter (p <0.05) before ovulation, in comparison to those in the other two groups. A final wave of the interovulatory interval emerged ~1 day earlier in Treatment 2 than in Treatment 1 ewes (p <0.05). Nutritional supplementation with lupin grain increased the number of 3-mm follicles in Treatment 2 ewes (p <0.05). The results of this study indicated that short-term nutritional flushing with lupin grain from mid- to late luteal phase did not consistently enhance ovulatory responses in non-prolific genotypes of ewes. Although the administration of lupins altered the timing of wave emergence, ovulatory follicle diameter, or duration of different stages of the follicular lifespan, it failed to increase the number of ovulatory follicles emerging in the penultimate and final waves of the estrous cycle in non-prolific Polish Mountain sheep.

Ovarian activity in dairy Saanen goats subjected to a short-term ovulation induction protocol and a single injection of lecirelin (GnRH analog) given 28 h or 34 h after progestin pre-treatment

Abstract Fixed-time artificial insemination (FTAI) and hormonal superovulation (SOV) are instrumental in enhancing genetic gain and productivity of commercial goat herds. The goal of this study was to document changes in antral follicle populations and ovulation in dairy Saanen does. Fifty-six animals received MAP sponges that were left in place for 6 days as well as 200 IU of eCG and 120 μg of cloprostenol i.m. 24 h before sponge withdrawal. Does were randomly divided into three groups: Gcon (n = 18) received 1 mL of saline 28 h after, whereas G28h (n = 19) and G34h (n = 19) received 25 μg of lecirelin i.m. 28 h or 34 h after sponge removal. Estrus was detected with intact bucks every 12 h and transrectal ovarian ultrasonography was carried out from the time of sponge removal until ovulation detection (8/8 h – 60 h after sponge removal) and then until 156 h after sponge withdrawal (12/12 h). There were no differences (P > 0.05) among GnRH-treated and control goats in estrus responses (G28h–57.9%; G34h–84.2%; Gcon–83.3%) and mean ovulation rates (G28h–100%; G34h–91.7%; Gcon–81.8%), but the intervals from MAP sponge withdrawal to ovulation and from the estrus onset to ovulation were less variable (P

Effect of PUFA Enriched Diet on Superovulatory Response, Embryo Quality, Embryo Recovery and Conception Rate in Cattle

The present study was designed to observe the effect of supplementation of PUFA enriched diet on superovulatory response, embryo quality, embryo recovery and conception in cattle. Donor (n=6) and crossbred recipient cows (n=24) were selected and divided into four groups viz; control (no treatment), T-1 (treatment given to recipient only), T-2 (treatment given to donor only) and T-3 (treatment given to both recipient and donor). The superovulatory response, mean ovulation rate ,mean embryo/ova recovered, recovery rate and average transferable embryos was found to be 75% v/s 100%, 12.25 ± 2.70 v/s 12 ± 0.71,3.5 ± 1.54 v/s 7.5 ± 1.60, 28.57% v/s 62.5 % and 50 % v/s 80 % in non-treated (control + T-1) and treated (T-2 + T-3) groups respectively. On the basis of our results, it can be concluded that flax seeds supplementation is effective in increasing above measured parameters following embryo transfer.

Early embryo development, number, quality, and location and the relationship with plasma progesterone in dogs

This research assessed the developmental stages and morphological quality of dog embryos collected during different stages of pregnancy as well as the relationship with serum progesterone recorded at insemination and embryo collection. Embryos were collected from 23 young mature bitches, that had been inseminated with fresh semen 3–6 days after the LH surge (day 0). Embryo flushing was performed on pregnancy days 8–11 (Group 1), 12–15 (Group 2), or 16–20 (Group 3). The location, number and morphological characteristics of the embryos were evaluated. A total of 120 embryos and 25 unfertilized oocytes were collected from bitches with a total of 156 corpora lutea (CL). The mean total embryo yield (total of embryos/CL) was 76.7 ± 5.9%, and the mean embryo recovery rate (number of flushed embryos/number of CL) was 70.6 ± 6.6%. The mean ovulation rate was 6.8 ± 0.5 and the mean number of embryos per bitch was 5.2 ± 0.6. Oocyte fertilization occurred following oocyte maturation. Most embryos in Group 1 (70.0 ± 18.6%) were collected at the 2 to 16 cell stage. The morula stage was first observed on day 11. Expanded blastocysts (EBLs) and hatched blastocysts were first flushed from the uterus on days 13 and 14, respectively. The EBL was the most abundant stage in Groups 2 and 3. After day 19, some embryos (n = 8) had already adhered to the endometrium. Although most recovered embryos were classified as very good, a greater number of low quality embryos was collected in the later gestational periods. A significant variation in the embryonic stages and location of embryos in early canine pregnancy was observed, as embryos entered the uterus independently of their developmental stage. Embryo yield and quality were independent of the serum progesterone concentration at insemination and recovery.

The use of multiple ovulation, embryo cryopreservation and embryo transfer techniques to facilitate movement of genetic material between countries

The objective of the study was to evaluate the use multiple ovulation and embryo transfer techniques in an indigenous Greek dairy breed of sheep. We stimulated selected donor ewes of the Karagouniko breed to produce large numbers of embryos after the induction of multiple ovulations by gonadotropin treatment (superovulatory response). A total of 50 Greek Karagouniko ewes were synchronised into oestrus using progestagen pessaries and superovulated for embryo transfer using ovine FSH. Six days following laparoscopic insemination with fresh semen ewes were flushed surgically and embryos collected. Subsequently, the embryo recovery, along with embryo cryopreservation, embryo survival and quality were assessed. The Karagouniko donor ewes achieved a mean ovulation rate of 11.9 (SE. 0.89). The ova Recovery rate was 80,9% and 87,6% of the ova recovered being fertilised. A total of 327 (77,5%) of the viable embryos were assessed as being of sufficient quality for cryopreservation. The embryos ranged from late morulae to expanded blastocyst and were frozen via a 3-step process in 1.5 M ethylene glycol following repeated washing and trypsination. Cryopreserved embryos were frozen and then transported to Scotland, UK. There, embryos were thawed rapidly and re-hydrated via a 2 step sucrose/ethylene glycol gradient. A total of 92.4% of embryos frozen remained suitable for transfer semi-surgically into synchronized Scottish Blackface ewes. 183 embryos were transferred in total with a 66.1% survival rate. The survival rate of frozen thawed blastocysts(75%) was significantly greater than (P<0.01) that for morulae (48%). It was concluded that MOET could be successfully applied in Greek dairy breeds of sheep as a means for genetic improvement. Frozenembryos could be a successful medium for the transportation of ovine genetic material from and to Greece, however, most likely the choice of embryonic stage for cryopreservation is crucial.

The influence of azaperone treatment at weaning on reproductive function in sows: ovarian activity and endocrine profiles during the weaning-to-ovulation interval

Azaperone can reduce stress caused by weaning and relocation of breeding sows, but its effects on reproductive processes are still poorly understood. The primary aim of this study was to describe and compare the endocrine and ovarian activity in ultrasonographically monitored second parity sows, with or without azaperone treatment at weaning (2 mg/kg BW i.m.). The intervals from weaning to the onset of estrus and ovulation were both greater (P<0.05) in azaperone-treated (n=12) than in control sows (n=12) by ~12 h. Mean daily growth rates of identified antral follicles were less (P<0.05) in azaperone-treated than in control sows (1.08±0.17 v.1.23±0.18 mm/day; mean±SD) and treated animals exceeded (P<0.05) controls in the mean ovulation rate (13.7±1.3 v. 12.6±1.2). A transient suppression of cortisol release was observed in the treatment group (at 10 and 30 min after azaperone injections) but circulating cortisol concentrations were variable in both groups of sows for the remainder of the study. The preovulatory rise in LH and estradiol secretion was delayed (P<0.05), and the duration of the LH surge was greater (P<0.001) in azaperone-treated sows compared with their control counterparts. The amplitude of episodic fluctuations in serum cortisol concentrations was correlated with the number of stillborn piglets in control sows (r=0.63, P=0.04). The amplitude and concentration of the preovulatory rise in estradiol secretion were negatively correlated with ovulatory response and litter size (r=−0.63 to −0.82, P<0.05), whereas the time at which the LH surge ended was directly related to the number of live-born piglets (r=0.82, P=0.002) in azaperone-treated animals. The present results indicate that administration of azaperone at weaning had a profound effect on preovulatory LH secretion as well as growth kinetics and estrogenicity of ovarian antral follicles. However, the causative associations among various characteristics of the preovulatory LH discharge, ovarian and adrenal steroid secretion post-weaning, and reproductive variables in sows remain equivocal.

Ovulation rate, antral follicle count, and circulating anti-Müllerian hormone in Trio allele carriers, a novel high fecundity bovine genotype

High fecundity genotypes in sheep are a valuable model to study the physiological mechanisms underlying follicle selection and the control of ovulation rate. Similar genotypes in cattle had not been described until the recent identification of a major bovine allele, termed Trio, which had a large effect on ovulation rate. The present study was designed to evaluate ovulation rate, antral follicle count (AFC), circulating ant-müllerian hormone (AMH), and the association among these measures in unstimulated and superstimulated Trio carrier cattle. We hypothesized that AFC and AMH would be variable among individual cows but would be similar between Trio carriers and non-carrier control cows and that there would be no association between these measures of follicle numbers and ovulation rate. In experiment 1, ovulation rate was determined during 4 consecutive estrous cycles in Trio carriers (n = 34) and non-carrier controls (n = 27). Ovulation rate, on average, was greater (P < 0.01) in Trio carriers (3.5 ± 0.2) compared to non-carrier controls (1.1 ± 0.1) with ∼70% of carrier cycles (n = 136) having 3–4 ovulations while only ∼5% had single ovulations. In contrast, non-carrier cycles (n = 108) were mostly single ovulation (89%) with none having more than two ovulations. In experiment 2, AFC, determined at wave emergence, was not different (P = 0.54) between Trio carriers (24.5 ± 1.3; n = 45) and non-carrier controls (23.1 ± 0.9; n = 37), and no correlation was found between AFC and mean ovulation rate in either genotype (r = −0.009 and r = −0.07; P > 0.70, respectively). In Experiment 3, circulating AMH was also not different between genotypes (P = 0.65) while correlations were found between AFC and AMH in Trio carriers (r = 0.43; P = 0.05; n = 27) and non-carrier controls (r = 0.78; P < 0.01; n = 19). In experiment 4, AFC and AMH were determined in Trio-carriers (n = 9) in relation to a synchronized follicular wave which was unstimulated or stimulated with exogenous FSH. Stimulation with FSH increased ovulation rate, compared to unstimulated Trio carriers, however no association was found between AFC or AMH and ovulation rate regardless of whether superstimulation with exogenous FSH was used. In conclusion, the novel high fecundity bovine genotype Trio, results in consistent multiple ovulations despite having similar AFC and AMH. Therefore, our results suggest that differences in antral follicle numbers during the final stages of follicle development are not a key component of the mechanism underlying multiple ovulations in Trio carriers.

Is progesterone the key regulatory factor behind ovulation rate in sheep?

Ovarian antral follicles in the ewe grow in an orderly succession, producing 3 to 4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH or LH pulsatility at proestrus. Prolific sheep tend to have a shorter luteal phase than nonprolific ewes and there is a great deal of evidence that luteal progesterone (P4), in addition to regulating LH release, may govern the secretion of FSH heralding the emergence of follicular waves. The specific purpose of this study was to determine whether or not extending the duration of the luteal phase in prolific sheep to that typically seen in nonprolific breeds would alter the follicle wave dynamics and ovulation rate. In 2 separate experiments, exogenous P4 (7.5 mg per ewe intramuscularly) was administered on day 11 at PM and day 12 at AM (day 0 = first ovulation of the interovulatory interval studied) in moderately prolific Rideau Arcott × Polled Dorset ewes (experiment 1, n = 8) and highly prolific Olkuska ewes (experiment 2, n = 7; TRT), whereas the equinumerous groups of animals served as controls (CTR). Transrectal ovarian ultrasonography was performed daily, and jugular blood samples were drawn twice a day from day 9 until the next ovulation. Progesterone injections resulted in relatively uniform increments in serum P4 levels, but the mean duration of the interovulatory interval did not differ (P > 0.05) between TRT and CTR groups of ewes in either experiment. The mean ovulation rate post-treatment was 1.6 ± 0.2 vs 3.2 ± 0.4 (experiment 1, P < 0.001) and 3.2 ± 0.8 vs 4.0 ± 1.0 (experiment 2, P > 0.05) in TRT vs CTR, respectively. The number and percentage of ovulating follicles from the penultimate wave of the interovulatory interval studied was 0.25 ± 0.16 vs 1.75 ± 0.45 (P < 0.01) and 25.0 ± 16.4% vs 75.0 ± 16.4% (P < 0.05) in experiment 1, and 0.50 ± 0.30 vs 1.60 ± 0.40 (P < 0.05) and 13.8 ± 9.0% vs 53.4 ± 16.7% (P < 0.05) in experiment 2, for TRT vs CTR, respectively. In summary, administration of P4 at the end of diestrus decreased the incidence of ovulations from the penultimate wave of the estrous cycle in both the moderately and highly prolific strains of sheep, but it reduced the ovulation rate only in moderately prolific ewes.

Effects of season and ovarian status on the outcome of long-term progesterone-based estrus synchronization protocols and ovulatory follicle development in Santa Inês ewes under subtropical conditions

This study set out to investigate the efficiency of long-term estrus synchronization protocols and ovulatory follicle dynamics in ultrasonographically monitored Santa Inês ewes during lengthening (LD; September−October) and shortening photoperiods (SD; April−May), and the transitional period (TP; January). In addition, the influence of ovarian status (e.g., size of antral follicles and/or presence of corpora lutea) at the outset of the estrus synchronization protocols on the ensuing development of ovulatory follicles was examined. Seventy sexually mature Santa Inês ewes were subjected to one of the two estrus synchronization regimens; on Day 0 (random day of the estrous cycle or anovulatory period), the ewes were fitted with an intravaginal progesterone (P4)-releasing (controlled intrauterine drug release [CIDR]) device, which was left in place for 14 days (G-1CIDR, n = 35) or replaced on Day 7 (G-2CIDR, n = 35), and received an intramuscular injection of 10 mg of PGF2α. The ewes allocated to the G-1CIDR group had mean serum P4 concentrations less than 2 ng/mL during the last 4 days of the synchronization protocol. There were no differences (P > 0.05) in mean ovulation rates between the two protocols tested nor among the ewes varying in ovarian status or studied at different times of the year, but ovulations occurred ∼12 hours later in the TP compared with the SD period (P < 0.05). Ovulatory follicles emerged earlier (P < 0.05) in the G-1CIDR group than in the G-2CIDR group (Day 8.3 ± 0.5 vs. 9.2 ± 0.4) and during LD (Day 7.1 ± 0.6) compared with the TP (Day 9.1 ± 0.6) and SD (Day 9.9 ± 0.5 of the protocol). In conclusion, the replacement of CIDR devices prevented the occurrence of lower-than-normal luteal phase levels of P4 at the end of the 14-day estrus synchronization protocol. However, although this procedure and seasonal influences altered certain growth characteristics of ovulatory follicles, there were no effects of these factors on the mean ovulation rate.

Ovarian function in captive owl monkeys (Aotus nancymaae and A. vociferans).

Ovarian function and morphology of owl monkeys (Aotus spp.) is inadequately known, but it is essential to describe this organ in detail to better understand reproductive patterns of the species. This study reports the anatomical and histological features of the ovaries from 41 owl monkeys, considering their reproductive status and parity. The corpora lutea (CL) and reproductive state had a significant effect on ovarian volume. Follicles were observed in both pregnant and non-pregnant subjects. All females in the luteal phase and pregnant females showed at least one cyclic or pregnancy CL. Mean ovulation rate was 1.89 CL/female, and the mean ovum mortality was 37.5%. There were no significant differences in ovarian volume related to parity. These results contribute to the scarce information available on the reproductive biology of owl monkeys and can aid in the development of biotechnologies involved in assisted reproduction.

178 IS PROGESTERONE THE DETERMINING REGULATORY FACTOR BEHIND OVULATION RATE IN EWES?

Ovarian antral follicles in the ewe grow in an orderly succession, producing 3–4 waves per oestrous cycle. In prolific sheep, some large antral follicles from the second-last wave of the oestrous cycle are added to the ovulatory follicles emerging just before oestrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH and/or LH pulsatility at pro-oestrus. Prolific sheep tend to have a shorter luteal phase than non-prolific breeds and there is a great deal of evidence that luteal progesterone (P4), in addition to regulating LH release, may govern the secretion of FSH heralding the emergence of follicular waves. The specific purpose of the present experiments was to determine whether or not extending the duration of the luteal phase would alter the ovulation rate in prolific sheep. In both studies, exogenous P4 (7.5 mg ewe–1 IM) was administered on Days 11 and 12 (Day 0 = ovulation) in moderately prolific Rideau Arcott x Polled Dorset (Exp. 1, n = 8) and highly prolific Olkuska ewes (Exp. 2, n = 7), while the equinumerous groups of animals served as controls (CTR). Transrectal ovarian ultrasonography was performed daily and jugular blood samples were drawn twice a day from Day 9 until ovulation. All single-time point observations were compared between groups by Student t-test. Progesterone injections resulted in uniform increments in serum P4 levels in all animals allocated to the treatment (TRT) groups. However, the mean duration of the interovulatory interval did not differ (P &gt; 0.05) between TRT and CTR groups of ewes in both experiments. The mean (± s.e.m.) ovulation rate was 1.6 ± 0.2 v. 3.2 ± 0.4 (Exp. 1; P &lt; 0.001) and 3.2 ± 0.8 v. 4.0 ± 1.0 (Exp. 2; P &lt; 0.05) in TRT v. CTR ewes, respectively. There were no differences in terms of the timing of penultimate and final wave emergence between the two subsets of animals studied in either experiment. The number/percentage of ovulating follicles from the penultimate wave of the interovulatory interval studied was 0.25 ± 0.16 v. 1.75 ± 0.45 (P &lt; 0.01)/25.0 ± 16.4% v. 75.0 ± 16.4% (P &lt; 0.05) in Exp. 1 and 0.50 ± 0.30 v. 1.60 ± 0.40 (P &lt; 0.05)/13.8 ± 9.0% v. 53.4 ± 16.7% (P &lt; 0.05) in Exp. 2, in TRT v. CTR animals, respectively. In summary, administration of P4 at the end of diestrus reduced the incidence of ovulations from the penultimate wave of the oestrous cycle in moderately and highly prolific strains of sheep. Therefore, progesterone appears to be a key endocrine signal governing the ovulation rate in cyclic sheep, presumably by acting directly at the level of the ovary. The present results may pave a way to devising a simple and inexpensive method of controlling lamb productivity in commercial flocks of sheep and fertility in other polyovulatory species.

Efficiency of oestrous synchronization by GnRH, prostaglandins and socio-sexual cues in the North African Maure goats.

This study aims to develop at different seasons, for local North African Maure goats, synchronizing protocols simultaneously to the standard 'S' protocol using progestagens in association with prostaglandins and gonadotropin. In late May, 40 goats were assigned to either the 'S' protocol or to a protocol where oestrus and ovulation were induced by the buck effect in single-injection progesterone-treated goats and provoking early luteolysis using prostaglandin 9days after exposure to bucks 'B'. During the 72h after the treatments ended, 15 and 5 goats expressed oestrus in the 'S' and 'B' protocols (p<0.01). Mean time to oestrus was shorter for 'S' than for 'B' goats. Ovulation rate averaged 2.1±0.22 and 1.60±0.35 for, respectively, 'S' and 'B' goats (p>0.05). During mid-September, 60 goats were assigned to either 'S' treatment, 'PGF' treatment where oestrus and ovulation were synchronized using two injections of prostaglandin 11days apart or to 'GnRH' treatment where the goats had their oestrus and ovulation synchronized with a GnRH (day 0)-prostaglandin (day 6)-GnRH (day 9) sequence. More 'S' goats were detected in oestrus over the 96-h period after the end of the treatments (88.8, 73.7 and 55% in 'S', 'PGF' and 'GnRH' treatments, respectively; p<0.05). Mean ovulation rates were 2.3±0.27, 1.33±0.27 and 1.33±0.27 for, respectively, 'S', 'PGF' and 'GnRH' goats (p<0.001). Despite a similar ovulatory response to 'S' protocol, efficiency of prostaglandin and GnRH-based treatments should be tested in mid-breeding season.

Comparing two different superovulation protocols on ovarian activity and fecal glucocorticoid levels in the brown brocket deer (Mazama gouazoubira)

BackgroundStress is a limiting factor in assisted reproduction in wild animals maintained in captivity. However, the knowledge of assisted reproduction techniques for wild animals is useful for future in situ and ex situ conservation programs. Thus, this study evaluated the ovulation rate, presence of functional corpora lutea and fecal glucocorticoid levels following treatments promoting superovulation in captive brown brocket deer.MethodsThe crossover design used six hinds, allocated to two groups (n = 6): eCG Treatment, CIDR for 8 days, followed by 0.25 mg of EB on day 0, 700 IU of eCG on day 4 following device insertion and 265 mug of PGF2alfa on day 8; and FSH Treatment, CIDR for 7.5 days, followed by 0.25 mg of EB on day 0, 130 mg of FSH in 8 equal doses and 265 mug of PGF2alfa on day 7.5. Induced adrenal activity and treatment efficacy were evaluated by corpora lutea (CL) counts and fecal glucocorticoid and progestin concentration (ng/g feces) analyses for five different phases: Pre, two days before treatment; Early, first four days of treatment; Late, last four days of treatment; Total, entire treatment period; and Post, five days posttreatment.ResultseCG Treatment resulted in the highest number of CL (P lower than 0.05). There was no significant difference for fecal glucocorticoid concentrations in five different time periods between the treatments; however Pre fecal glucocorticoid concentrations (90.06+/−19.64) were significantly different from Late (200.76+/−26.39) within FSH Treatment. The mean fecal progestin concentration and mean ovulation rate were higher in eCG Treatment (4293.69+/−769.47, 7.0+/−1.8) than in FSH Treatment (1571.26+/−240.28, 2.6+/−0.8) (P lower than or equal to 0.05).ConclusionsAlthough the eCG Treatment induced a good superovulatory response, with the formation of functional corpora lutea, we cannot yet affirm that we have established a suitable protocol for induction of SOV in the species M. gouazoubira because approximately 65% of the deer showed premature regression of the corpora lutea. Moreover, multiple FSH applications in FSH Treatment resulted in a low ovulation rate and induced an increase in fecal glucocorticoid levels.

Seasonality of oestrus, ovulation and ovulation rate of Sicilo-Sarde sheep

This study aimed to investigate monthly changes in oestrus and ovulatory activity of Sicilo-Sarde sheep. Experimental animals comprised 25 adult and 10 maiden ewes at the start of the experiment. For 12 consecutive months (September-August), the females were exposed to natural photoperiod and permanently kept in presence of seven aproned rams. Oestrus was checked daily and ovarian activity was monitored by monthly endoscopies during the last week of each month. Ovulation rate for a particular month was assessed as the sum of corpora lutea or corpora albicans present on both ovaries at the time of endoscopy. Proportions of ewes observed in oestrus at least once a month were lowest in March (24.3%) and highest in June and October (100%). They tended (p<0.06) to be different according to age, dropping during summer from a common value of 100% in June to 85.7% and 90% in July and then to 57.1% and 70% in August for, respectively, the Adults and Maiden females. Overall, the experimental period, 92.5% and 83.8% of Adult and Maiden ewes ovulated at least once per month (p<0.01) respectively. Least proportions ovulating, attained 60% and 30% in April for, respectively, Adult and Maiden ewes before peaking up at 100% again in May (p<0.05). Mean (±SD) ovulation rate of Sicilo-Sarde sheep is 1.40±0.503. Adult females had a higher (p<0.001) ovulation rate than Maiden sheep with respective average values of 1.51±0.516 and 1.16±0.373. It varied little between months and decreased in Adults from a maximum value of 1.95 in October to a minimum value of 1.16 in April. It is concluded that benchmarking seasonal variations of reproductive activity in Sicilo-Sarde breed would be valuable in designing improved management calendars for this breed.

Functional morphology of the female genital organs in the wild ring-tailed coati (Nasua nasua) in the northeastern Peruvian Amazon

This study examines the functional morphology of genital organs of 45 wild female ring-tailed coatis (Nasua nasua (L., 1766)) in the Peruvian Amazon. The coati shows a seasonal reproductive pattern, with a concentration of births between January and March. The pregnancy rate during the reproductive season was 64.7%. Mean litter size was 4.2 fetuses and mean ovulation rate was 4.5 follicles per pregnant female, resulting in a low rate of embryo or oocyte mortality of 9.8%. The observed vaginal pattern in our study suggests that vaginal cytology could be a useful indicator for the phase of estrus. The present evaluation provides reproductive information that may be a key component in the development of management strategies for both captive and wild coati populations.

Functional morphology of the genital organs in the wild paca (Cuniculus paca) female

Functional morphology of the genital organs is a key knowledge component for enhanced understanding of physiological patterns and for the determination of the reproductive performance in wild species. This study examines the morphology of genital organs of 133 paca females in the wild. Estimated conceptions and parturitions were mostly (83.7% and 75.5%, respectively) localized in the wet season. The pregnancy rate between 57.1% and 61.4% suggests an estimated yearly production of 1.37–1.48 parturitions and a long estimated farrowing interval of 247–266 days. Although large antral follicles were observed in all females, pregnant females had a greater number of antral follicles than females in the luteal phase. The average litter size was 1.03 foetuses per pregnant female, and mean ovulation rate was 1.33 follicles, resulting in a rate of reproductive wastage of 28.7%. The constituent active luteal tissues of the ovary were oestrous cyclic, pregnancy and accessory CL. The 50% of pregnant females in the late pregnancy stage lacked pregnancy CL, suggesting that placenta may become the mean source of progesterone during late stages of pregnancy. Results of the present study suggest that the observation of the vaginal closure membrane should not be an accurate tool for diagnosing oestrus in the paca female.

Prolific strains of Barbarine sheep are characterized by increased ovulation rate due to extended period of ovulatory follicle recruitment and co-dominance effects

Preovulatory follicle dynamics and plasma oestradiol around the time of onset of oestrus as well as ovulation rate were assessed, during non-breeding season, in prolific (W; n=20) and non prolific (AB; n=20) strains of the Barbarine sheep. Oestrus cycles were synchronized with progestagen sponges for 14 days followed by introduction of rams. Transrectal ultrasonographic monitoring of the ovaries was carried out from the day of pessaries removal up to oestrous exhibition. Blood samples were collected every 4h and were analyzed for plasma concentrations of oestradiol by radioimmunoassay. Laparoscopy was performed 11 days after introduction of rams to assess number of corpora lutea (CL). Results indicate that along the first 5 days after introduction of rams, 20 and 14 ewes of respectively the AB and W ewes exhibited oestrus (P<0.01). Ewes of the W strain had more medium (3.5–5.4mm) follicles than AB ones during the follicular phase; the difference being significant (P<0.01) 24h before oestrus. The number of medium follicles prior to oestrus changed little in AB ewes but declined rapidly from 5.8±0.7 to 4.0±0.6 in W females (P<0.05). Differences in medium follicles between strains were not reflected in the number of large (≥5.5mm) or the growing large follicles during the follicular phase. Around oestrus, plasma oestradiol concentrations were higher for W in comparison to AB ewes (22.3±12.6 vs. 11.8±6.2pg/ml; P<0.01) and mean ovulation rates were 1.8±0.8 and 1.1±0.3 for respectively W and AB ewes (P<0.01). In conclusion, the increased ovulation rate in the W strain is related to an extended period of follicle recruitment with appearance of co-dominance effects.

Functional Morphology of the Female Genital Organs in the Peruvian Red Uakari Monkey (Cacajao Calvus Ucayalii)

Functional morphology may provide important information that could improve methodologies for the diagnosis of the reproductive phase of females, and develop assisted breeding techniques for wildlife. This study examined features of genital organs in 19 Peruvian red uakari monkey (Cacajao calvus ucayalii) females in different reproductive stages, collected from wild animals hunted for food by rural communities in the North-eastern Peruvian Amazon, in order to provide knowledge on the reproductive physiology of this species. The observed mean ovulation rate was 1.4 follicles, and the observed maximal follicle diameter was 0.8 cm. After ovulation, the matured follicle luteinizes resulting in functional CL. In case of oocyte fertilization, the pregnancy CL grows to a maximum of 1.2 cm in diameter, and luteal volume per female decreases related to the advance of pregnancy. Pregnant females also present follicular activity until late pregnancy, but non-ovulated follicles do not undergo atretic processes and apparently transform to accessory CL, resulting in a contribution of 30% of the total luteal volume. All pregnant females delivered a single fetus at term, resulting in a rate of reproductive wastage of 20% of oocytes or embryos. The endometrium and the endometrial glands in non-pregnant females in the follicular phase show a significant increase related to the follicular growth, reaching a high proliferation in non-pregnant females in the luteal phase. The red uakari monkey showed different vaginal epithelium features in accordance with the reproductive state of the female, suggesting that vaginal cytology could be a successful methodology with which to characterize the estrous cycle of this species. The present reproductive evaluation of the Peruvian red uakari monkey provides important information that could improve the development of assisted reproductive techniques in non-human primates.

Ovarian functionality in Poeppig's woolly monkey (Lagothrix poeppigii)

This study examined ovarian features of 60 Poeppig's woolly monkey females in different reproductive stages, collected from wild animals hunted by rural communities in the North-eastern Peruvian Amazon, to provide knowledge on the reproductive physiology of this species. The observed mean ovulation rate was 1.73 follicles, reaching a maximum diameter of 1.0cm. After ovulation, the matured follicle luteinizes resulting in functional corpora lutea (CL). In case of oocyte fertilization, the “pregnancy” CL grow to a maximum of 2cm in diameter, and luteal volume decreases related to the advance of pregnancy. Pregnant females have waves of follicular activity until late pregnancy, but dominant follicles do not attain the maximum diameter of pre-ovulatory follicles. Some non-ovulated follicles of 1mm maximum diameter do not undergo atretic processes and transform to accessory CL by luteinization of the membrane granulosa, resulting in a contribution of up to 7% of the total luteal volume. All pregnant females delivered at term only 1.00 foetus, resulting in a rate of reproductive wastage of 33.3% of embryos.