Verification of the usefulness of Estrophan inj. Spofa in the control of reproductive parameters in sows after weaning of piglets]

Cloprostenol, a prostaglandin F2-alpha analogue, used in the Czechoslovak preparation Oestrophan ing. Spofa was tested by a new nontraditional use. The effect of cloprostenol use on reproductive parameters of sows after piglet weaning was followed in a set of 456 experimental and 434 control sows. The effect of single intramuscular instillation of cloprostenol was tested in five partial observations: to multiparous sows at a dose of 175 micrograms on the day of weaning (experimental group no. 1), on day 1 after weaning (group no. 2), 500 micrograms on day 1 after weaning (group no.3), to primiparous sows at a dose of 500 microgram on day 1 after weaning (group no. 4). The treatment used in group no. 4 was also applied to 42 primiparous sows kept on a farm with regular occurrence of post-weaning anoestria of sows (experimental group no. 5). These parameters were evaluated: dynamics of oestrus onset within five, and/or ten, days after weaning, average length of the weaning--first insemination interval, conception rate after the first insemination in dependence on terminated deliveries and parameters of piglet litter. Cloprostenol application did not have a statistically significant effect on the evaluated reproductive parameters. The percentage of multiparous, and/or primiparous, sows in which the oestrus onset was not detected by the 10th day after weaning, did not show any large differences in the various experimental and control groups (17.09 vs. 16.55%, 23.53 vs. 32.56%, 13.66 vs. 18.13%, 29.54 vs. 30.30%; P > 0.05). On the farm with regular occurrence of post-weaning anoestria there were 73.81% of primiparous sows with oestrus onset after cloprostenol instillation and 71.43% primiparous sows without treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of different hormonal treatments on oestral and ovarian responses in Moroccan Beni Arouss goats during anoestrus and breeding season

The efficacy of eight combinations of fluorogestone acetate (FGA, 20 or 40 mg as intravaginal device during 11 days), equine chorionic gonadotropin (eCG, 300 or 500 UI injected 48 hr before FGA removal) and prostaglandin F_2α (cloprostenol, 0 or 50 μg injected 48 hr before FGA removal) aiming at induction and synchronization of oestrus and ovulation was evaluated during the anoestrus season in spring and during the breeding season in autumn in adult Beni Arouss goats. Oestrous behaviour was recorded between 12 and 60 hr after FGA removal. Blood samplings allowing to assess onset of the pre‐ovulatory LH surge and increase of progesterone as sign of an active corpus luteum were performed, respectively, between 20 and 60 hr and 3, 5, 8 and 15 days after FGA removal. No season‐related differences (spring vs. autumn) were observed for oestrous response (95% vs. 93%), pre‐ovulatory LH surge (94% vs. 84%) and luteal response after 3–8 and 11–15 days post‐treatment (respectively 92% vs. 66% and 92% vs. 98%). The onset of oestrus (21 [13–53] vs. 32 [12–54] hr) and LH surge (26 [20–60] vs. 38 [22–60] hr) occurred significantly later in autumn. FGA (40 vs. 20 mg) in autumn significantly delayed the onset of oestrus (36 [16–54] vs. 23 [12–47] hr) and LH surge (44 [26–58] vs. 33 [22–60] hr). Significant treatment‐related differences were recorded for onset of LH surge (earliest for 20 mg FGA, 300 IU eCG, 50 μg PGF_2α) and onset of luteal phase (latest for 40 mg FGA, 300 IU eCG, 50 μg PGF_2α). In conclusion, the hormone combinations tested appeared equally effective in terms of oestrous and ovulation rates. Season has influenced significantly the onset of oestrus and LH surge, and the high dose regimen of FGA delayed the ovarian response in autumn.     

Responsiveness to Progestagen-eCG-Cloprostenol Treatment in Goat Food Restricted for Long Period and Refed

For 6 months, 10 adult Saanen crossbred goats were fed undernutrition diet (70% maintenance), and finally five goats were refed for 6 weeks with 150% maintenance. In all animals oestrus was synchronized using 45 mg FGA vaginal sponge for 11 days, 300 IU eCG and 50 microg cloprostenol 48 h prior to sponge removal. From oestrus onset, during a 24-h period, blood samples were collected for oestradiol and NEFA assay. Ovulation was verified by laparoscopy 3 days after sponge removal. Body mass loss was 18.62 +/- 3.03% of initial weight and in refed goats body weight recovery was 90.63 +/- 3.56%. NEFA level was higher in restricted goats (p < 0.05). Fifty per cent of underfed goats (2/4) and all refed goats (4/4) exhibited oestrus and ovulation. Significant relationship (p < 0.05) was found between weight loss and the interval sponge removal-oestrus onset (r = 0.91) or ovulation rate (r = 0.70). Only in the refed group was the ovulation rate related to the oestradiol amount (r = 0.99) (p < 0.05). Collectively results showed that a short period of improved feeding re-established the responsiveness of oestrus synchronization in chronically fasted goats.     

Effect of parity and progesterone priming on induction of reproductive function in Saanen goats by buck exposure

The response to the buck effect and the use of progesterone priming was studied in Saanen goats during the non-breeding season (April and May) in northern Mexico (26° N). Forty goats were assigned randomly in equal numbers (n = 10) to four treatment groups in a 2 × 2 factorial arrangement. Treatment consisted of two dosages of progesterone (P4) (0 or 5 mg) and two categories of goats, nulliparous and multiparous. Both parity groups were exposed to sexually active bucks previously exposed to a long-day photoperiodic scheme (16 h light day^− 1). All multiparous goats (20/20) displayed estrous behavior within the first 10 days of buck exposure, while 70% (14/20) of the nulliparous goats showed estrus (P > 0.05). During the first five days of buck exposure, the percentage of unprimed goats in estrus was 70% points lower than the primed goats, although progesterone priming did not affect the occurrence of estrus (90% vs 80%; P > 0.05) after 10 days of buck stimulus. The time to onset of estrus was four days shorter (P < 0.05) in P4-treated goats compared with controls. Pregnancy rate did not differ between primed and unprimed goats (80 vs 60%; P > 0.05), but this variable was higher (P < 0.05) in multiparous than nulliparous goats (95 vs 45%). It was concluded that it is possible to induce fertile estrus in Saanen goats during the non-breeding season in northern Mexico using sexually active bucks. The use of progesterone priming can accelerate the response of goats to the buck stimulus although it was ineffective in improving the pregnancy rate of goats. Additionally, a higher proportion of the multiparous goats got pregnant compared with the nulliparous goats induced to estrus by the buck stimulus.     

Effect of delaying the time of insemination with sex-sorted semen on pregnancy rate in Holstein heifers

The objective of the study was to evaluate the interval from onset of oestrus to time of artificial insemination (AI) to obtain the optimum pregnancy rate with sex-sorted semen in Holstein heifers. Heifers in oestrus were detected and inseminated only by using heat–rumination neck collar comprised electronic identification tag at the age of 13–14 months. Heifers (n = 283) were randomly assigned to one of three groups according to the timing of insemination at 12–16 hr (G1, n = 97), at 16.1–20 hr (G2, n = 94) and at 20.1–24 hr (G3, n = 92) after reaching the activity threshold. The mean duration of oestrus was 18.6 ± 0.1 hr, and mean peak activity was found at 7.5 ± 0.1 hr after activity threshold. The mean interval from activity threshold to ovulation was 29.4 ± 0.4 hr. The overall pregnancy per AI (P/AI) was 53.0% at 29–35 days and 50.9% at 60–66 days after AI. There was a significant reduction between G1 (13.8 ± 1.4 hr) and G3 (7.9 ± 1.4 hr) related to the intervals from AI to ovulation time. Sex-sorted semen resulted in significantly higher P/AI at 29–35 days when heifers inseminated in G3 (60.9%) after oestrus than those inseminated in G1 (49.5%) and G2 (48.9%). In terms of fertility, when the temperature–humidity index (THI) was below the threshold value (THI ≤65) at the time of AI, there was a tendency (≤65; 57.2% vs. > 65; 47.1%) for high pregnancy rate. There was no effect of sire on P/AI. In addition, the interaction of the technician with the time of AI was found significant, and three-way interaction of technician, sire and time of AI was tended to be significant on pregnancy rate. Thus, in addition to delaying the time of insemination (between 20.1 and 24 hr) after oestrous detection, THI and experienced technician were also found to be critical factors in increasing fertility with the use of sex-sorted semen in Holstein heifers.     

Pregnancy and offspring sex ratio following insemination with SexedULTRA and conventional semen in cows in a commercial beef operation

Pregnancy rate per AI (PR/AI) and breeding season pregnancy rates between insemination with sexed semen (SS; at 18 hr after the onset of oestrus) and conventional semen (CS; at 12 hr after the onset of oestrus,) and offspring gender ratio between two groups were compared. Angus cross cows (n = 686, during 2019 and 2020 breeding seasons) were oestrus-synchronized using Select-Synch + CIDR protocol and were observed thrice daily for oestrus until 72 hr after PGF2α administration. Cows expressed oestrus (n = 513) were inseminated with either SS (n = 246; SexedULTRA 4M™; y chromosome-bearing sperm) or CS (n = 267). Cows (n = 173) that failed to express oestrus at 72 hr after PGF2α received 100 μg of GnRH and CS insemination concomitantly. Two weeks later, cows were penned with natural service sires (bull:cow ratio 1:25) for 45 days. Pregnancy was diagnosed 30 days after bull removal. Calves' gender was determined at birth. For cows that expressed oestrus, PR/AI did not differ (p > .1) between SS (65.0%) and CS (66.7%) groups. The overall PR/AI differed (p < .05) between SS (65.0%) and CS (56.4%) groups. The natural service PR differed (p < .001) but breeding season PR (p > .05) did not differ between SS vs. CS groups. Bull:heifer gender ratio following AI was 88:12 and 52:48 for SS and CS groups, respectively, with an overall 66:34 ratio. Bull:heifer gender ratio for the two breeding seasons was 79:21 and 52:48 for SS and CS groups, respectively, with an overall 62:38 ratio. In conclusion, the fertility of SS insemination at 18 hr after onset of oestrus was 97% of CS insemination at 12 hr after onset of oestrus. Though breeding season pregnancy did not differ between SS and groups, preferred calf gender was 25 percentage points greater for SS over CS application. The gender accuracy was 88%.     

Ovarian Response to Oestrous Synchronization Protocol Based on Use of Reduced Doses of Cloprostenol in Cyclic Goats

The objective of this study was to assess the efficacy of two reduced doses vs a high/luteolytic dose of cloprostenol on luteolytic activity and synchronization of oestrus in cyclic goats. Experiment 1, included 24 goats randomly allocated to three groups: control group (group H) received a single high dose of cloprostenol (87.5 μg; 1.0 ml; i.m.) and M and L groups, which received half (43.75 μg; 0.5 ml) and a third (26.25 μg; 0.3 ml) of the highest dose, respectively. Experiment 2, included 24 goats randomly assigned to the same experimental groups. Each group was treated using two injections of cloprostenol administered 10 days apart to synchronize oestrus. Transrectal ultrasonographic scanning (US) was performed to detect the presence, size and development of corpora lutea and ovarian follicles. Furthermore, detection of oestrus was performed every 12 h between 24 and 72 h after the second injection of cloprostenol, and the luteolytic effect was verified by US. In Experiment 1, all goats that had corpora lutea at timing of treatment regressed their corpora lutea. In Experiment 2, the occurrence of oestrus and the interval between treatment to onset of oestrus were: 100%, 49.5 ± 3.0 h; 100%, 51.0 ± 3.0 h; and 75%, 56.0 ± 3.5 h for H, M and L groups, respectively. The development of preovulatory follicles and occurrence of subsequent corpora lutea were similar among groups. In summary, the use of 26.25 μg of cloprostenol is effective for the synchronization of oestrus in cyclic goats.     

First Service Pregnancy Rates Following Post‐AI Use of hCG in Ovsynch and Heatsynch Programmes in Lactating Dairy Cows

Lactating dairy cows (n = 667) at random stages of the oestrous cycle were assigned to either ovsynch (O, n = 228), heatsynch (H, n = 252) or control (C, n = 187) groups. Cows in O and H groups received 100 μg of GnRH agonist, i.m. (day 0) starting at 44 ± 3 days in milk (DIM), and 500 μg of cloprostenol, i.m. (day 7). In O group, cows received 100 μg of GnRH (day 9) and were artificially inseminated without oestrus detection 16–20 h later. In H group, cows received 1 mg oestradiol benzoate (EB) i.m., 24 h after the cloprostenol injection and were artificially inseminated without oestrus detection 48–52 h after the EB injection. Cows in C group were inseminated at natural oestrus. On the day of artificial insemination (AI), cows in all groups were assigned to subgroups as follows: human Chorionic Gonadotrophin (O‐hCG) (n = 112), O‐saline (n = 116), H‐hCG (n = 123), H‐saline (n = 129), C‐hCG (n = 94) and C‐saline (n = 93) subgroups. Cows in hCG and saline subgroups received 3000 IU hCG i.m. and or 10 ml saline at day 5 post‐AI (day 15), respectively. Pregnancy status was assessed by palpation per rectum at days 40 to 45 after AI. The logistic regression model using just main effects of season (summer and winter), parity (primiparous and pluriparous), method₁ (O, H and C) and method₂ (hCG and saline) showed that all factors, except method₁, were significant. Significant effects of season (p < 0.01), hCG and parity (p < 0.01), and a trend of parity and season (p < 0.1) were detected. A clear negative effect of warm period on first service pregnancy rate was noted (p < 0.01). The pregnancy rate was the lowest in the H protocol during warm period (p < 0.05). Treatment with hCG 5 days after AI significantly improved pregnancy rates in those cows that were treated with the H protocol compared with saline treatments (41.5% vs 24.8%; p < 0.01). O and H were more effective in primiparous than in pluriparous cows (46.1% vs 29.9%; p < 0.1 and 43.6% vs 24.6%; p < 0.01). First service pregnancy rates were higher in primiparous hCG‐treated than in pluriparous hCG‐treated cows (57.9% vs 32.3%; p < 0.01). The pregnancy rate was higher for the hCG‐treated cows compared with saline‐treated cows during warm period (37.9% vs 23.6%; p < 0.001).     

Timing of Ovulation and Conception Rate in Primiparous and Multiparous Cows after Synchronization of Ovulation with GnRH and PGF2α

Conception rates after Ovsynch have been higher in primiparous than in multiparous cows. The objective of this study was to investigate whether this difference might be due to differences in ovulation rate or follicular size. The experiment was conducted with 136 Holstein Frisian cows from a commercial herd in Brandenburg, Germany. All cows were synchronized using Buserelin (GnRH analogue) at day ?10, Tiaprost (PGF_2α analogue) at day ?3 and again GnRH at day ?1. Timed artificial insemination (TAI) was carried out 16–20 h after the second dose of GnRH on day 0. Milk samples for analysis of milk progesterone were obtained on days ?17, ?10, ?3 and at TAI. Progesterone concentrations were used to determine the stage of oestrus cycle at the start of the synchronization protocol and to investigate the presence of functional luteal tissue before treatment with PGF_2α and TAI. All animals were examined by ultrasound at the second treatment with GnRH, at AI, 8 and 24 h after AI. Overall synchronization rate (proportion of cows with an ovulation within 40 h after GnRH) was 86.8% in primiparous and 88.2% in multiparous cows, respectively. Ovulation occurred earlier in primparous than in multiparous cows (p < 0.05) and ovulatory follicles were smaller. Conception rates were numerically higher in primiparous cows but the difference was not significant. Cows that displayed signs of oestrus on day ?1 and received an additional AI on this day were more likely to conceive than cows that only received TAI 16 to 20 h after GnRH2. It is concluded that ovulation occurs earlier in primiparous than in multiparous cows after Ovsynch. However, a significant relationship between these differences and the probability of conception could not be established.     

Combined treatment with oestradiol benzoate,d‐cloprostenol and oxytocin permits cervical dilation and nonsurgical embryo recovery in ewes

This study examined the feasibility of transcervical embryo recovery after the hormonal treatment to induce cervical dilation, following the 7‐day oestrous synchronization protocol in multiparous Santa Inês ewes. A total of 23 cyclic ewes received two doses of 37.5 μg of d‐cloprostenol by latero‐vulvar route 7 days apart. After the second injection of d‐cloprostenol, the ewes were checked for oestrus (every 12 hr) and then mated by fertile rams throughout the oestrous period. All ewes received 37.5 μg of d‐cloprostenol (latero‐vulvar) and 1 mg of oestradiol benzoate by either intramuscular (EBim group; n = 12) or intravaginal (EBivg group; n = 11) route 16 hr before embryo flushing. Twenty minutes before the flushing, 50 IU of oxytocin were administered intravenously. The oestrous response (i.e., the percentage of ewes that showed signs of oestrous behaviour after the second d‐cloprostenol injection) was 91.3% (21/23). The proportion of successfully penetrated ewes (81.8% compared with 80.0%), the mean duration of embryo flushing (24.7 ± 2.0 min compared 26.2 ± 1.9 min), the flushing fluid recovery rate (94.8 ± 1.3% compared with 91.0 ± 2.9%) and the average number of structures recovered per ewe (0.5 ± 0.4 compared with 0.8 ± 0.4) did not vary (p > 0.05) between the EBim and EBivg groups. Viable embryos were recovered from 41.2% (7/17) of successfully penetrated ewes. It can be concluded that nonsurgical (i.e., transcervical) embryo collection can be performed in oestrous‐synchronized Santa Inês ewes pretreated with d‐cloprostenol, oxytocin and oestradiol benzoate, with the latter hormone administered by either the intramuscular or intravaginal route.     

Subtropical goats ovulate in response to the male effect after a prolonged treatment of artificial long days to stimulate their milk yield

The objectives of this study were to determine (i) if in subtropical goats that gave birth during mid‐December, the exposition to an artificial long‐day photoperiod consisting in only 14 hr of light per day can increase the milk yield and (ii) to test whether these females can respond to the male effect at the end of the prolonged photoperiodic treatment. In experiment 1, 17 lactating goats were maintained under natural short days (control group), while another 22 goats were maintained under artificial long days (treated group) consisting in 14 hr light and 10 hr darkness starting at day 10 of lactation. The continuous exposition to an artificial long‐day photoperiod produced an increase in the milk yield level during the first 110 days of lactation (time × treatment interaction; p = .01), while none of the milk components were modified due to the photoperiodic treatment (p > .05). In experiment 2, all control and treated anovulatory goats were submitted to the male effect using photostimulated males. All females showed oestrous behaviour within the first 10 days that were in contact with males (100% in both groups; p > .05). Thus, the latency to onset of oestrus did not differ between females from control (58.2 ± 3.0 hr) and treated (62 ± 4.6 hr) groups. Male exposition provoked ovulation independently if females were previously under long days or natural photoperiod (96 vs 100%, respectively; p = .79). It was concluded that exposure to 14 hr of light per day in subtropical goats that gave birth in late autumn stimulates milk yield without preventing the ovulation in response to the male effect at the end of the prolonged photoperiodic treatment.     

Pronuclear Embryo Yield in Canindé and Saanen Goats for DNA Microinjection

The objective of this study was to examine the effect of donor breed on pronuclear‐stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen‐cloprostenol treatment. Forty‐eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH‐FSH‐P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 μg of GnRH and they were hand‐mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction.     

Administration of hCG 5 days after Breeding and Reproductive Performance in Nulliparous Dairy Goats

The objective of this study was to investigate the effect of hCG administration 5 days after breeding on plasma progesterone (P4) concentration and reproductive performance of oestrous-induced nulliparous dairy goats. A total of 59 nulliparous goats (36 Alpine and 23 Saanen) received intravaginal sponges with 60 mg medroxyprogesterone acetate for 9 days plus 200 IU equine chorionic gonadotrophin (eCG) and 22.5 microg d-cloprostenol 24 h before sponge removal. After detection of oestrus (day of oestrus = day 0) and breeding, 49 females were randomly assigned, according to the breed, into two treatments (T1 and T2). In T1 (n = 25) and T2 (n = 24), animals received intramuscular injection of 1 ml of saline solution (control) or 250 IU hCG, respectively, 5 days after breeding. Plasma P4 concentration (ng/ml) was determined from blood sampled on days 0, 5, 7, 13, 17, 21, 28 and 45 after breeding. Animals were scanned by transrectal ultrasound (5 MHz probe) on days 35 and 70 after breeding for detection of pregnancy. Plasma P4 concentration did not differ (p > 0.05) between treatments in all days, but it was increased (p < 0.05) in Saanen than in Alpine goats from days 13 to 45. Pregnancy and parturition rates, litter size and gestation period were similar (p > 0.05) to treatments and breeds. Results of this study indicate that human chorionic gonadotrophin (hCG) administration 5 days after breeding did not significantly alter reproductive performance in dairy nulliparous goats and that plasma P4 differed between Saanen and Alpine goats.     

ACE inhibition in goats under fixed‐time artificial insemination protocol increases the pregnancy rate and twin births

To assess the effect of the angiotensin‐converting enzyme (ACE) inhibition on the efficiency of the fixed‐time artificial insemination (TAI), 69 goats were divided randomly into two groups: enalapril (n = 35) and control (n = 34). In the experiment, all animals underwent the protocol of fixed‐time artificial insemination for 12 days. Enalapril group received enalapril maleate dissolved in saline (Enalapril, Lab Teuto Ltda) subcutaneously at the following doses: 0.2 mg/kg/day in D0‐D2; 0.3 mg/kg/day in D3‐D6 and 0.4 mg/kg/day in D7‐D11. The control group received the corresponding volume of 0.9% saline solution. We performed a single insemination 36 hr after sponge removal using frozen semen from two adult male goats with recognized fertility. The ultrasound pregnancy diagnosis was 30 days after the artificial insemination (AI). There was significant increase in pregnancy rates and twinning as well as a decrease in foetal loss in animals receiving enalapril (p < .01). The use of ACE inhibitors during the TAI protocol was shown to be a promising alternative to increase the efficiency of such reproductive biotechnology.     

Repeated pregnant mare serum gonadotropin‐mediated oestrous synchronization alters gene expression in the ovaries and reduces reproductive performance in dairy goats

This study aimed to elucidate the effects of repeated pregnant mare serum gonadotropin (PMSG) treatment for oestrous synchronization (ES) on ovarian gene expression and reproductive parameters in Xinong Saanen dairy goats, the dominant breed of dairy goat in China. The experiment was carried out at the Research Station of Northwest A&F University (NWAFU), China (34°16′N, 108°4′E). Forty‐one does were randomly assigned to groups receiving ES treatments thrice every fortnight (3‐PMSG group; n = 19), or ES treatment only once simultaneously with the third ES treatment in the 3‐PMSG group (1‐PMSG group; n = 22) during middle of the breeding season from late July (14 hr light) until late September (12 hr light). ES treatment was performed via intravaginal insertion of a controlled internal drug release (CIDR) device impregnated with 300 mg progesterone (P4), followed by 300 IU PMSG injections 48 hr before CIDR withdrawal. Oestrus was monitored using vasectomized bucks. Ovaries of three goats in oestrus from both groups were harvested for morphological examination and RNA sequencing (RNA‐Seq). Then, all the oestrous goats in the 1‐PMSG (n = 21) and 3‐PMSG (n = 11) groups were artificially inseminated twice. The 3‐PMSG group showed reduced oestrous rate (57.89%), pregnancy rate (31.58%) and litter size (1.17) compared, respectively, with 95.45%, 68.18% and 1.67 for 1‐PMSG group (p < 0.05). However, no differences were found in the ovarian morphology between the 1‐PMSG and 3‐PMSG groups (p > 0.05). RNA‐Seq revealed 114 differentially expressed genes (DEGs) in the ovaries of the 3‐PMSG group, among which GCG, FSTL3, TET3 and AQP3 were deemed novel and promising candidate genes for regulating fertility. The present study indicates that the three‐time PMSG treatment dysregulated several ovarian genes, thereby reducing reproductive performance.     

Pseudopregnancy in Saanen Goats (Capra hircus) Raised in Northeast Brazil

The prevalence of pseudopregnancy over 44 months was investigated in 23 Saanen goats raised in Northeast Brazil during continuous oestrous cycling (cyclic group) or after synchronization of oestrus (synchronized group). The goats were monitored by ultrasonography and their plasma progesterone profile. The overall prevalence of pseudopregnancy was 30.4% (7/23). In the cyclic group, 28.6% (4/14) of goats showed pseudopregnancy, while in the synchronized group the prevalence was 33.3% (3/9). There was no significant difference between the groups (p>0.05). The mean (+/- SD) length of pseudopregnancy, as shown by the progesterone profile, was 121.6 +/- 33.5 days, ranging from 70 to 155 days. The study defined the prevalence of pseudopregnancy in Saanen goats raised in Northeast Brazil for the first time. This finding identified a major problem for this breed, as without treatment such animals remain unproductive until the spontaneous resolution of the condition. More research seems desirable to ascertain the prevalence of this condition in other breeds in this region of Brazil.     

Fixed‐time post‐cervical artificial insemination in weaned sows following buserelin use combined with/without eCG

Fixed‐time post‐cervical artificial insemination (FTAI) drastically reduces labour requirements and increases the use of boars with higher genetic merit. This study evaluated the efficiency of eCG administration combined with/without the GnRH agonist buserelin for the induction and synchronization of ovulation in weaned sows submitted to FTAI. The sows were allocated into three groups. In the control group, the first artificial insemination was performed at the onset of oestrus and repeated every 24 hr. In the eCG+GnRH group, sows received 600 IU eCG at weaning and buserelin (10 μg) after 86–89 hr of eCG, and in the GnRH group, sows received only buserelin after 86–89 hr of weaning. The hormone‐treated sows received a single FTAI after 30–33 hr of buserelin application. All the sows were inseminated with homospermic doses (1.5 × 10⁹ sperm cells/50 ml). The interval between weaning and ovulation was shorter (p < .05) in the eCG+GnRH (133.3 hr) and GnRH (135.9 hr) groups than the control (141.5 hr) group. In the eCG+GnRH group, the sows ovulated earlier (p < .05) than those in the GnRH group (44.5 vs. 48.2 hr after buserelin administration). The reproductive performance of GnRH sows was not compromised when only sows exhibiting oestrus at the time of insemination were considered, but lower farrowing rate and smaller litter size were observed in eCG+GnRH sows. The reproductive performance of eCG+GnRH sows was primarily compromised because the insemination was performed outside the optimal time relative to ovulation; therefore, it is advisable to inseminate them before 116–122 hr after weaning.     

Efficacy of PGF(2α) on pre-ovulatory follicle and corpus luteum blood flow

The aim of this study was to evaluate the effect of cloprostenol administration on the blood flow of pre-ovulatory follicle (PF) and corpus luteum (CL), progesterone secretion and pregnancy outcome in buffaloes subjected to AI. The trial was performed on 75 Italian buffaloes at 182 ± 8 days in milk. Synchronized animals were randomly divided into two groups on the day of oestrus: Group T (n = 37) received a 0.524 mg intramuscular injection of cloprostenol and Group C (n = 38) received saline. Ultrasound examinations of the ovaries were performed 5 h after AI on the PF and 10 and 20 days after AI on the CL. Resistive (RI) and pulsatily index (PI) were calculated by colour-Doppler mode in each examination. Blood samples were collected on days 10, 20 and 25 after AI for progesterone assay and 25 days after AI, ultrasonography was performed to assess pregnancy, which was confirmed on day 45. Subjects pregnant on day 25 but not on day 45 were considered to have undergone late embryonic mortality (LEM). Statistical analysis was performed by anova. No differences were found in PF dimensions, CL size and blood flow on day 10 and 20 after AI between treated and control groups. Pre-ovulatory follicle area was higher in buffaloes that resulted pregnant on day 25 after AI compared to those that were non-pregnant (2.13 vs 1.66 cm in pregnant and non-pregnant buffaloes, respectively), while non-pregnant buffaloes showed higher values of RI (0.49 vs 0.30; p < 0.05) and PI (1.0 vs 0.37; p = 0.07) compared to pregnant subjects. Treatment by cloprostenol did not influence pregnancy rate both on day 25 (31/75; 41.3%) and 45 (27/75; 36.0%), progesterone levels and incidence of LEM (4/31; 12.9%). In conclusion, cloprostenol administration at the time of AI does not seem to affect PF and CL blood flow.     

Effect of types of breeding on embryo survival following first AI in lactating Holstein cows

The main objective was to investigate the effects of timed-AI protocols versus AI following oestrus detection on circulating progesterone (P4) and embryo survival after first service in Holstein cows. Cycling status was determined by ultrasonography and by plasma P4 concentrations 14 and 26 days after calving, and only cows with a corpus luteum and/or P4 ≥ 1 ng/ml were used. Cows were randomly allocated to one of three types of breeding: DO (n = 80), received GnRH-7d-PGF2α-3d-GnRH and Ovsynch56 was initiated 7 days later; G7G (n = 70), received PGF2α-2d-GnRH and Ovsynch56 (GnRH-7d-PGF2α-56h-GnRH-16h-AI) was initiated 7 days later; or AI based on oestrus detection, EDAI (n = 60). Progesterone was also determined at AI and 8, 16, 18 and 20 days after AI; ISG15 and MX2 mRNA abundance were determined 16 days after AI. Mean plasma P4 at AI was greater in the EDAI group compared with DO and G7G groups, while after AI, P4 was greater in DO and G7G groups compared with EDAI group. However, the percentage of cows with a concentration of P4 < 0.8 ng/ml at AI did not differ among groups. Relative mRNA abundance of ISG15 and MX2 was greater in the DO and G7G groups compared to those in EDAI group. Pregnancy per AI 16, 32 and 60 days after AI was greater (p < .05) in cows in the DO group compared with those in EDAI group (47.5%, 38.8% and 36.3% vs. 30.0%, 21.7% and 15.0%). Pregnancy losses between 16 and 60 days after AI were greater (p < .05) in cows in the EDAI (50.0%) group compared to those subjected to DO (23.7%) or G7G (24.1%). In conclusion, the use of timed-AI synchronization protocols resulted in greater circulating P4 concentrations post-AI and greater embryo survival following first service in lactating Holstein cows.     

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 9 days after exposure to bucks ‘B’. During the 72 h 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 11 days 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.