Presence Of Corpus Luteum Research Articles

Roe Deer Reproduction in Western Poland: The Late Autumn Rut Phenomenon.

Roe deer (Capreolus capreolus L.) populations in Poland are characterized by low productivity, which is why their reproductive potential was investigated. The presence of corpora lutea (CL) on the ovaries of females hunted in autumn and winter in the years 2015 and 2016 was assessed. Most animals were post-rut and most often had multiple ovulations. However, in early autumn 2015, 60% of the females had no CL. Therefore, they did not participate in mating at the turn of July/August. Those that did ovulate were found to have one CL. In late autumn, 97% of the females were post-rut, mostly with twin ovulations. This confirmed the occurrence of a late autumn rut. This phenomenon had been suggested in studies but not confirmed. In contrast, almost 100% of roe deer ovulated in summer in 2016. It was hypothesized that the reason for the low mating activity of roe deer in the summer of 2015 was heat stress and limited food resources. The summer was exceptionally hot, with many days in July and August when temperatures exceeded 30 °C. The heat combined with low rainfall led to extreme drought. Meanwhile, July and August are the months of mating activity for roe deer. The late autumn rut allowed the roe deer-a monoestrous species-to limit the consequences of a decrease in mating activity or fertility during the hot summer. Global warming may affect roe deer reproduction, so climatic conditions should be considered in population studies, not only in terms of food availability.

P-585 Vaginal progesterone associated with oral dydrogesterone versus vaginal progesterone for luteal support in letrozole-hcg cycles for thawed embryo transfer: a non-inferiority prospective cohort study

Abstract Study question Does micronized vaginal progesterone (MVP) associated with oral dydrogesterone (DYG) an alternative for luteal support in Letrozole-hcg cycles for thawed embryo transfer? Summary answer The association of MVP and DYG is a non-inferior alternative to only MVP for luteal support in thawed embryo transfer in Letrozole-hcg cycles. What is known already Endometrial preparation is essential for thawed embryo transfer. Several protocols involving different luteal support with progesterones are available. Moreover, the presence of corpus luteum decreases the obstetrical morbidity mainly linked to hypertensive disorders. Letrozole-hcg administration is a good alternative for frozen embryo transfer (FET). However, the literature lacks information about the comparison among the different protocols for luteal support in Letrozole-hcg cycles. Dydrogesterone is an oral progesterone with some unique characteristics which could be utilized with some advantage for luteal support, including oral administration and some immunological activity. Study design, size, duration This is a prospective non-inferiority cohort study performed at an infertility clinic including patients performing the first FET cycle during 2023. Reproductive outcomes were compared between patients receiving 600 mg (3x200 mg) of MPV or 40 mg of DYG plus 400 mg of MVP after Letrozole-hcg administration. Participants/materials, setting, methods All patients (aged 23-39 years) undergoing their first FET cycle during 2023 were included in this study (n = 169), divided into two groups: MVP+DYG (n = 54) or MVP (n = 115) for luteal support after Letrozole-hcg. Letrozole was administered for 5 days (2,5 mg/bid) and hcg was done when a dominant follicle reached 18 mm with a follicular endometrium measuring at least 7 mm. Main results and the role of chance Both groups were equivalent in terms of age, infertility aetiology, BMI and AMH (P > 0.05). Moreover, the proportion of cleavage or blastocyst stage was also similar between both groups (57% blastocyst transfer for MVP+DYG and 50% blastocyst transfer for MVP group, P > 0.05). The number of transferred embryos was (mean ±SD) 1.6±0.5 for both groups, P > 0.05. Furthermore, the number of top-quality embryos (cleavage stage or blastocyst) was also similar, P > 0.05. Moreover, clinical pregnancy (> 12 weeks) was 42% in MVP+DYG group versus 31% in the MVP group (-0.22-1.27, P = 0.156) and the early pregnancy loss per positive hcg test did not differ (18% for MVP+DGY and 22% for MVP, P = 0.687). In addition, we performed a multivariable analysis controlling possible confounders for clinical pregnancy: BMI, age, AMH, embryo quality, infertility aetiology and embryo stage during the transfer, and only age (0.86; 95%CI -0.229 to -0.064, P = 0.001) was related to clinical pregnancy. Limitations, reasons for caution The main limitation is the cohort design of our study, with an inherent risk of bias (selection bias). Moreover, we calculated this study to achieve the power for a non-inferiority comparison, not superiority comparison. Wider implications of the findings This is the first study comparing MVP+DYG to only MVP in patients submitted to FET using the Letrozole-hcg protocol. We demonstrated in this non-inferiority study the usefulness of adding DYG. Moreover, our results were promising showing a trend towards better pregnancy rates after MVP+DYG. Trial registration number not applicable

Corpus luteum presence in the bovine ovary increase intrafollicular progesterone concentration: consequences in follicular cells gene expression and follicular fluid small extracellular vesicles miRNA contents.

It is well described that circulating progesterone (P4) plays a key role in several reproductive events such as oocyte maturation. However, during diestrus, when circulating P4 is at the highest concentrations, little is known about its local impact on the follicular cells such as intrafollicular P4 concentration due to corpus luteum (CL) presence within the same ovary. Based on that, our hypothesis is that the CL presence in the ovary during diestrus alters intrafollicular P4 concentrations, oocyte competence acquisition, follicular cells gene expression, and small extracellular vesicles (sEVs) miRNAs contents. P4 hormonal analysis revealed that ipsilateral to the CL follicular fluid (iFF) presented higher P4 concentration compared to contralateral follicular fluid (cFF). Furthermore, oocyte maturation and miRNA biogenesis pathways transcripts (ADAMTS-1 and AGO2, respectively) were increased in cumulus and granulosa cells of iFF, respectively. Nevertheless, a RT-PCR screening of 382 miRNAs showed that three miRNAs were upregulated and two exclusively expressed in sEVs from iFF and are predicted to regulate cell communication pathways. Similarly, seven miRNAs were higher and two exclusively expressed from cFF sEVs and are predicted to modulate proliferation signaling pathways. In conclusion, intrafollicular P4 concentration is influenced by the presence of the CL and modulates biological processes related to follicular cell development and oocyte competence, which may influence the oocyte quality. Altogether, these results are crucial to improve our knowledge about the follicular microenvironment involved in oocyte competence acquisition.

201 The presence of corpus luteum affects gene expression in oocytes and cumulus cells after in vitro maturation in mares

201 The presence of corpus luteum affects gene expression in oocytes and cumulus cells after in vitro maturation in mares

PSII-10 Effect of Equine Chorionic Gonadotrophin-Like Glycoprotein Treatment on Fertility in Angus Cows Subjected to a 7-Day Co-Synch Protocol

Abstract This study evaluated the effect of administering a glycoprotein with equine chorionic gonadotropin like activity produced by recombinant DNA technology (eCG-like) associated with a 7-d Co-Synch protocol on estrus rate (ER) and pregnancy per timed AI (P/TAI). A total of 1,344 suckled Angus cows (primiparous, n = 381; multiparous, n = 963) from 11 herds were scanned at initiation of synchronization protocol by transrectal ultrasonography and the presence of corpus luteum (CL) and uterine tone was used to classify them by cycling. On day -10, cows received 100 μg GnRH analogue and a progesterone intravaginal device (IVD; 1.0g progesterone) for 7 days. At IVD removal, cows were administered 500 μg of cloprostenol and randomly assigned to receive 400 IU of eCG-like glycoprotein (Syntex S.A., Argentina, PCT/EP2019/073277; eCG-like, n = 665) or to remain as untreated (Control, n = 679). Also on day -3, paint was applied on the sacrum to the tail head of each cow. Finally, 100 μg GnRH analog were injected concurrently with TAI on Day 0 (66h after IVD removal) and the ER was evaluated by the degree of paint loss. Pregnancy to TAI was determined on day 30 by transrectal ultrasonography when an embryo and fluid were detected in the uterus. Body condition score (BCS; scale = 1-9) was evaluated on days -10 and 30. Optimal BCS was considered ≥ 5 and BCS balance between days -10 and 30 was classified as negative (lost BCS) or positive (maintained or gained BCS). The associations among treatment, parity, cyclicity at initiation of protocol, optimal BCS on day -10, and their interactions and ER and P/TAI were analyzed by GLIMMIX (SAS 9.3). Estrus expression and BCS balance were also included as effects in the model of pregnancy per TAI. The effect of herd was included as a random effect. The model specifications included an option to retrieve the mean, SEM, and an adjustment for multiple comparisons (Tukey-Kramer). The percentage of acyclic cows was 31.3%. The ER in cyclic cows was 64.9% and the eCG-like treatment increased ER only in anestrus cows (55.8 vs. 44.3%; Treatment x cyclicity interaction; P = 0.03). The percentage of cows with negative BCS balance was 27.2%. The P/TAI in cows with positive BCS balance was 48.4% and the eCG-like treatment increased P/TAI only in cows with negative BCS balance (44.7% vs. 30.5%; Treatment x BCS balance interaction; P = 0.01). In conclusion, the addition of a recombinant eCG-like glycoprotein to a 7-day Co-Synch protocol increased estrus expression in anestrus Angus cows and P/TAI in those with negative body condition score balance. However, this addition did not influence the estrus expression in cycling cows or on P/TAI in those with positive BCS balance.

Blue LED light treatment of pregnant mares is not detrimental to gonadal development in their offspring

A light program transmitted via blue LED light directed at one eye from individual light masks (Equilume, Kildare, Ireland) to pregnant mares from the middle of December onwards advanced the onset of foaling with birth of mature and healthy foals, but they were slightly smaller than foals from untreated control pregnancies (Lutzer et al., Domestic Anim Endocrinol 2022;78:106675). Differences, however, equilibrated within the first year of life. In this study we followed the hypothesis that light treatment of pregnant mares is without detrimental effects on body size and gonadal development of offspring after puberty. A total of 47 warmblood horses born and raised on the same stud farm to blue LED light-treated (17 males and 9 females) or control mares (14 males and 9 females) were included. At 24 months of age, their body weight, height at withers and cannon bone circumference was determined. In males, the external genitalia were examined, testis size was measured by transcutaneous ultrasound. The total testicular volume (TTV) was calculated. In females, a transrectal ultrasound examination of the genital tract was performed, the presence of corpora lutea was detected via plasma progesterone concentration and the antral follicle count (AFC) was assessed. Statistical comparisons weremade by analysis of variance (general linear model) with group (blue light vs. control) and sex (male vs. female) as between subject factors (IBM SPSS 27). Results are given as mean ± SEM. There were no group or sex differences with regard to bodyweight or height at the withers. The cannon bone circumference was larger in male vs. female horses (p<0.001) but not affected by blue light treatment during pregnancy. Testes were classified as normal in size and location (Love et al., J Reprod Fertil Suppl 1991;44:99-105) in 13 of 17 blue light and 11 of 14 control colts (n.s., chi2 analysis). The TTV was 232±14cm3 in the blue light and 218±11cm3 in the control group (n.s.). Abnormal testicular development was diagnosed in 7 males with unequal testicular size in 3 blue light and 2 control animals, both testes too small (1 blue light) or unilaterally cryptorchid (1 control). In females, no abnormalities were present. A corpus luteum (progesterone >1ng/ml) was present in 8 / 9 females from the blue light and 5 / 8 from the control group. The AFC was 20.6±2.5 in blue light and 22.1±3.7 in control females (n.s.). Results demonstrate that blue LED light treatment of pregnant mares has no detrimental effects on body and genital tract development of their offspring at two years of age.

Can body temperature be a tool to detect ovulation in the mare?

Body temperature variations occur around ovulation in bovine (Suthar et al. 2011; Sakatani et al. 2016) and ovine (Barros de Freitas et al. 2018). Previous studies in the mare were unable to determine such a relationship (Ammons et al. 1989; Hasson and Rahawy 2022). Nevertheless, in another study, a decrease of body temperature within 6 hours after ovulation was highlighted (Bowman et al. 2007). Authors, however, performed a temperature monitoring only at fixed hours. The present work uses identification chips equipped with a temperature sensor (BioThermo™, Antelliq) implanted in the mare neckline to be able to follow temperature variations across 24 hours. Seven mares were monitored around ovulation (2.4±0.9 days before and 3.6±1.7 days after), two of whom were followed across two consecutive ovulations. Phases of the reproductive cycle were determined using daily transrectal ultrasonography. Briefly, three phases were identified: follicular phase (F) when identifying a dominant follicle with a diameter >30mm and uterine edema score at least “+” (scoring from “-“ to “+++”); ovulation day (Ov) being the first day (from 0:00 to 23:59) of corpus luteum appearance; luteal phase (CL) from the day after ovulation with a presence of corpus luteum. Body temperature was measured using a device produced for research-purposes only (Ikalogic, France) able to record temperature automatically every 10 minutes. A total of 4,780 temperature recordings (F n=2,410;Ov n=965; CL n=1,405) were obtained from the 9 studied ovulations and mean body temperature per half an hour was calculated for each mare in order to simplify the statistical analysis. To study temperature variations, paired comparisons between phases were performed (Ov vs F; Ov vs CL; F vs CL) using the temperature differences at each time set. Thus, using a linear mixed model (LMM) temperature differences were compared to zero. Individuals were set as random effect while time set was a fixed effect. Significant higher temperatures in the Ov phase compared to the F phase were identified between 4:30 and 8:00 with a minimum difference of 0.51±0.26°C and a maximum of 0.92±0.26°C. Moreover, temperatures were significantly lower during Ov phase compared to CL phase at specific time sets (from 10:30 to 16:00; 18:30 and from 20:00 to 21:00) with a minimum temperature difference of 0.29±0.17°C and a maximum difference of 0.60±0.16°C. These results are more time specific than in other farm species, probably due to the longer estrus duration in horses. In conclusion, temperature variations do occur around ovulation. A more complete study, however, studying temperature along the whole reproductive cycle is needed to better understand the underlying physiological processes.

Analeptic efficacy of Tinospora cordifolia ethanolic leaf extract and its loaded Phytoniosome on enzymatic and non-enzymatic antioxidants in a rodent model of Polycystic ovary syndrome

IntroductionPCOS (Polycystic ovary syndrome) is being known as a significant metabolic and reproductive disorder deliberating to increased risk for type 2 diabetes. Tinospora cordifolia is frequently used in traditional system of medicine where the leaf of the plant possesses pharmacological properties like hypoglycemic, anti-inflammatory and antioxidant activity. In recent years the Niosomes a novel drug delivery system is gaining more attention because of their biodegradability, toxicity reduction, improved therapeutic effectiveness and absorption enhancement. In our present study an attempt is made to examine the ameliorative effect of ethanolic leaf extracts of Tinospora cordifolia (ELETC) and Tinospora cordifolia loaded phytoniosomes (nELETC) on enzymatic and non-enzymatic antioxidants in PCOS female rats that are induced by mifepristone. Materials and MethodsPCOS was induced by administrating 4mg/kg b. w. Mifepristone to female rats for 8 days and confirmed by persistent estrous cycle. 200mg /kg b. w of ELETC and nELETC extracts were given to the rats which attained PCOS condition for 28 days. The enzymatic antioxidants SOD, CAT, GR, GST and GPx and non-enzymatic antioxidants GSH, ascorbic acid and α-Tocopherol were estimated followed by Histopathological analysis. ResultThe antioxidants showed decreased levels in the PCOS induced rats. The treatment with the drug nELETC reverted the antioxidant levels back to normalcy. From the histopathological studies we can understand that corpus luteum, antral follicles and primordial follicular cells were absent with the formation of follicular cyst in the mifepristone induced PCOS rats. nELETC drug treated rats showed the presence of corpus luteum with graafian follicles and primordial follicle cells, with the absence of follicular cyst, indicating nELETC could regain the functional ability of the ovaries from PCOS condition. ConclusionFrom the restoration of antioxidant status we can conclude that nELETC extract can be effectively used in the management of PCOS.

133 Anatomical evidence for kisspeptin and dopaminergic neuron interaction in the diestrous mare

Dopamine (DA), via dopaminergic neurons, modulates prolactin secretion from the pituitary by tonic inhibition of lactotropes. Previously, kisspeptin (Kp) attenuated the prolactin response to the DA antagonist, sulpiride, in diestrous mares and enhanced the prolactin response to sulpiride in estradiol-primed mares. Whether or not Kp can modulate prolactin by acting on DA neurons has yet to be described in horses; therefore, the objective of this study was to determine if Kp and kisspeptin receptor (Kiss1r) co-localize with DA neurons, thus providing evidence for a direct action of Kp on DA neurons. Hypothalami from 4 light-horse diestrous mares, aged 6 to 21, were obtained following euthanasia. Mares were determined to be diestrous based on presence of corpora lutea and progesterone concentrations. Immediately following euthanasia, the carotid artery was perfused with sodium nitrite and 4% paraformaldehyde before decapitation and dissection of hypothalami. Immunofluorescent double labeling of tyrosine hydroxylase (TH) and Kp, as well as TH and Kiss1r, was carried out on paraffin-embedded hypothalamic sections using validated antibodies. Whole slide scans were analyzed for double-labeled cells; percentage of DA neurons colocalized with Kp-ir cell bodies and fibers, as well as percentage of DA neurons colocalized with Kiss1r-ir cells, were calculated and averaged for multiple sectionsper horse from rostral to caudal throughout the hypothalamus. Similarly, percentage and number of Kp or Kiss1r-ir cell bodies co-colocalized with TH-ir cells were calculated for different hypothalamic regions: the arcuate nucleus (Arc), ventromedial nucleus (VMH), and dorsomedial nucleus (DMH), and compared using Kruskall Wallis with Dunn's multiple comparison test. DA neurons were observed lining the third ventricle and spread from the Arc to the DMH, with little to none present in the posterior nucleus. TH and Kp expressing cell bodies co-localized between 8 and 30%, with less in the caudal DMH (P ≤ 0.05) compared with the Arc. Kp fibers synapsed with TH-expressing cell bodies at a low percentage, between 0 and 16%, with less connections in the DMH (P ≤ 0.05) than in the ARC. TH and Kiss1r co-localized between 20 and 65%, with similar distribution throughout the Arc, VMH, and DMH in rostral sections. In caudal hypothalamic sections, co-localization was greater (P ≤ 0.05) in the Arc compared with other areas that express lower or no DA neurons. Co-localization of TH and Kiss1r as well as co-localization and synaptic attachment of Kp on TH positive cells suggests a direct effect of kisspeptin on DA neurons to modulate prolactin release.

Effects of early weaning on the reproductive performance of suckled Nelore cows in the subsequent breeding season.

This study aimed to evaluate the effects of early weaning (EW) on body composition, hormone concentrations and metabolites, and reproductive performance of Nelore cows in the subsequent breeding season (BS). Suckled cows that became pregnant by timed-AI (TAI) in the 2020-BS were exposed in 2021 to early weaning at 150 d (27 primiparous [PRI] and 74 multiparous [MUL]) or conventional weaning (CW) at 240 d postpartum (30 PRI and 77 MUL). Body weight (BW) and body condition score (BCS) were determined at 2020-BS, EW, CW, prepartum, and 2021-BS. Blood samples were collected at EW, CW, prepartum (54.75 ± 0.56 d prepartum), and 2021-TAI and assayed for insulin-like growth factor-1 (IGF-I), non-esterified fatty acid (NEFA), and β-hydroxybutyrate (BHB) concentrations. In 2021-BS, cows were exposed to a P4/E2-based protocol for TAI at day 0 (D0), and a second TAI was performed at D22 in females detected with luteolysis (D20) by Doppler ultrasound. The presence of corpus luteum (CL) on D10, estrous expression, and dominant follicle (DF) diameter, and blood perfusion (BP) on D2 and D0 were determined. Data were analyzed by ANOVA or logistic regression of SAS as a 2 × 2 factorial with main factors of parity (PRI or MUL) and weaning strategy (EW or CW). An interaction of parity and weaning strategy was not observed (P > 0.1), but the weight (kg) and BCS were greater (P < 0.05) in MUL cows at the five timepoints, and EW cows were heavier than CW at the moment of CW (541 vs. 493 kg; and 5.3 vs. 4.3), prepartum (551 vs. 506 kg; and 5.2 vs. 4.4) and 2021-BS (475 vs. 450 kg; and 4.5 vs. 3.7). Plasma urea concentration at 2021-BS was greater (P = 0.01) for PRI than for MUL. A parity-by-time interaction was observed (P ≤ 0.05) for concentrations of IGF-I, NEFA, and BHB. PRI cows had greater (P ≤ 0.05) concentrations of IGF-I at EW and greater (P ≤ 0.05) prepartum concentrations of NEFA and BHB than MUL cows. The proportion of cows with CL at D10 was not affected (P > 0.1) by weaning but was greater (P < 0.05) in MUL than in PRI cows (40.4 vs. 15.7%). The diameter of DF and proportion of BP on D0 were greater (P < 0.05) in EW cows than in CW cows. The pregnancy rate (P/AI, %) at the first TAI was greater (P < 0.05) in EW cows (60% vs. 45%), whereas no difference (P > 0.1) was observed at the second TAI. Cumulative P/AI (first and second TAIs) was greater (P < 0.05) in EW cows (81% vs. 63%). In conclusion, weaning at 150 d in Nelore cattle is a strategy to successfully recover the parous cow's body condition and to improve pregnancy success in the next BS, regardless of the cow's parity order.

Effects of early weaning on productive and reproductive performance of Nelore heifers

Abstract We aimed to evaluate the effects of early weaning on the productive and reproductive characteristics of Nelore heifer progeny. Ninety-five calves from primiparous (PRI) and multiparous (MUL) dams were assigned to one of two weaning strategies; 1) early weaning at 150 d (149 ± 1.97) of age (EW; n = 16 from PRI and 31 from MUL); or 2) conventional weaning at 240 d (247 ± 2.41) of age (CW; 16 from PRI and 32 from MUL). All heifers received ~5 g/kg of body weight (BW) of creep-feed as fed from 90 d of age until weaning. After weaning, each group of heifers was transferred to a Brachiaria spp. paddock and received 5 g/kg of BW of a protein-energy supplement until 12 mo of age. Then, heifers were confined and fed a diet with a ratio of 79:31 (corn silage: concentrate) for 4 mo, during which they were submitted to a hormonal protocol to induce puberty and timed artificial insemination (TAI). Reproductive tract score (RTS, 1 to 5 scale: 1 being infantile and 5 being cyclic) and endometrial thickness were determined at 12 mo of age, rump fat thickness (RFT), and BW every 28 ± 4 d through the breeding season, and plasma concentrations of IGF-I were evaluated at 12, 14, and 16 mo. At 15.6 mo of age heifers were submitted to a P4/E2 protocol for TAI at day 0 (D0), and a second TAI was performed at D22 in nonpregnant heifers. Ultrasound was used to determine the presence of corpus luteum on D10 and dominant follicle (DF) diameter and blood perfusion on D2 and D0. Data were analyzed using SAS by ANOVA or logistic regression. Though heifers from EW were lighter (P &amp;lt; 0.05) than CW at postweaning time points and CW presented a greater (P = 0.002) RFT than EW heifers from 11 to 15 mo, weaning strategy did not affect (P &amp;gt; 0.1) body condition score at TAI. Concentrations of IGF-I did not differ (P &amp;gt; 0.1) between heifers weaned at 150 and 240 d. The proportion of pubertal heifers, endometrium tone and thickness, and RTS at 16 mo did not differ (P &amp;gt; 0.1) between EW and CW groups. The diameter of DF on D2 and D0 and follicular blood perfusion on D0 were greater (P &amp;lt; 0.05) for heifers in the CW group than EW group, but P/AI at first and second TAI did not differ (P &amp;gt; 0.1) between groups. In conclusion, early weaning in Nelore heifers moderately reduces postweaning growth but does not affect puberty and reproductive performance before the breeding season when submitted to confinement.

Evaluation of Medical and Economical Efficacy of Some Protocols for Treatment of Postpartum Clinical Endometritis in Holstein Dairy Cows

Endometritis is one of the most common postpartum diseases which affect daily cows. It causes severe economic losses through increasing treatment cost, days open, service per conception and decrement in milk yield. This study was conducted to evaluate medical efficacy and economic profitability of some treatment protocols for clinical Endometritis. Forty cycling Holstein dairy cows suffering from Endometritis were divided equally and treated as follow: Group 1: cows with presence of corpus luteum (CL) on their ovaries which received PGF2-α. Group 2: cows with presence of CL received PGF2-α + cephapirin (Metricure®) (500mg cephapirin) by intrauterine infusion. Group 3: cows without presence of CL were treated with Metricure® only. Group 4: cows without presence of CL received 100 ml of Lugol's Iodine solution (0.5%) intra-uterine infusion.The results showed that Group-2 animals recorded the fewest days to complete cure and days open and the highest conception rate when compared to other groups. Hematological result at 10th day post-treatment, showed that all the treatment protocols significantly decreased total leukocytic count, neuytrophils%, lymphocytes% and monocytes% except Group-1. Also, all the treated groups recorded significant decrease in serum level of C-reactive protein (CRP) and inteleukin-6 (IL-6). Concerning economical aspect, treatment protocol of Group-2 was the best. In general, treatment with cephapirine (Metricure®) is the best choice for treatment of clinical endometritis in cattle either in presence or absence of CL.

Oocyte developmental capacity is influenced by intrinsic ovarian factors in a bovine model for individual embryo production

The ovary and its hormones may have major effects on the in vitro developmental capacity of the oocytes it contains. We related intrinsic ovarian factors namely the presence of corpus luteum (CL) and/or dominant follicle (>8 mm) and the follicular count to cumulus expansion (CE), embryo development, and blastocyst quality in a bovine model. Cumulus-oocyte-complexes (COCs) were aspirated from follicles between 4 and 8 mm in diameter. In vitro embryo production was performed in a fully individual production system. The follicular fluid from which COCs were collected was pooled (per ovary) to evaluate the estrogen, progesterone, and insulin-like growth factor-1 (IGF-1) concentrations. Cumulus oocyte complexes collected from ovaries without a CL presented a greater CE than COCs derived from ovaries bearing CL. The absence of ovarian structures increased the blastocyst rate when compared to oocytes derived from ovaries with a CL, a dominant follicle, or both. Blastocysts derived from ovaries without a dominant follicle presented higher total cell numbers and a lower proportion of apoptosis than blastocysts derived from ovaries containing a dominant follicle. Cumulus oocyte complexes collected from ovaries with high follicular count resulted in higher cleavage than from ovaries with low follicular count, but the blastocyst rate was similar between groups. Ovaries bearing a CL had greater progesterone and IGF-1 follicular fluid concentrations in neighboring follicles than ovaries without a CL. Selection for bovine ovaries without CL or dominant follicle can have positive effects on CE, embryo development, and blastocyst quality in an individual embryo production system set-up.

What are the factors associated with pregnancy loss after timed-artificial insemination in Bos indicus cattle?

Pregnancy loss (PL) has important impacts on the profitability of livestock production systems, although it is not widely reported, particularly in Bos indicus cattle. The present study retrospectively evaluated PL after timed-artificial insemination (TAI) in Bos indicus (Nelore) beef cows corresponding to several factors, such as parity, body condition score (BCS), presence of corpus luteum (CL) at the beginning of TAI protocols, expression of estrus, and hormonal manipulations during the TAI protocol. Data from two experiments performed during three breeding seasons (BS) were reanalyzed. Both experiments evaluated adding GnRH treatment at TAI in a 7-d estradiol (E2) plus progesterone (P4)-based protocol, with intravaginal P4 implant removal on Day 7 combined with treatment with 0.5 or 1.0 mg E2 cypionate and 300 IU eCG, and TAI on Day 9. In addition, during BS 2 and 3 (Exp 2), cows were randomized to receive or not a PGF treatment on Day 0 (beginning of the TAI protocol). In all BS, presence of CL and BCS were evaluated at the beginning of TAI protocols, follicle size and expression of estrus were evaluated at TAI. The PL was assessed between the first pregnancy diagnosis (∼35d) and parturition. There were no effects of hormonal manipulations within TAI protocols of different BS on PL. There was no interaction between GnRH treatment at TAI and the other variables within BS, and there was no main effect of GnRH treatment on PL (without = 10.1% [102/1007] vs. with = 10.4% [114/1100]). The addition of PGF on Day 0 had no effect on PL (11.5% [102/886] vs. 10.5% [89/850]), as well as EC dose to induce final ovulation (10.8% [89/827] vs. 11.2% [102/909] for 0.5 and 1.0 mg, respectively). Primiparous had greater PL than multiparous cows (14.0% [77/550] vs. 8.9% [139/1557]), and cows not expressing estrus near TAI had greater PL than those expressing estrus (13.5% [57/422] vs. 9.7% [156/1617]). There was no interaction between follicle size at TAI and GnRH treatment on PL. However, probability of PL decreased linearly as follicle size at TAI increased. There were no effects of service number (first TAI or resynchronization), BCS, or presence of CL on D0 on PL. In addition, PL was not affected by sire within any of the BS. In conclusion, some factors that are known to impact pregnancy per AI also influenced PL, such as parity and expression of estrus, although, other aspects such as BCS, number of services, and presence of CL on D0 did not affect PL. Moreover, commonly implemented treatments to increase fertility (e.g., PGF on Day 0 and increasing EC dose to 1.0 mg) did not affect PL. Finally, the GnRH treatment at TAI had no effect on PL and did not interact with any of the variables, an important result, since GnRH at TAI also increases fertility in Bos indicus beef cows.

ASSOCIATION BETWEEN THE ABSENCE OF CORPUS LUTEUM AND THE RISK OF PLACENTAL INSUFFICIENCY IN PREGNANT WOMEN AFTER ASSISTED REPRODUCTION PROCEDURES

The main objective was to compare if the presence of corpus luteum (CL) was associated to an increased risk of placental pathologies in spontaneous (SP) and/or assisted reproductive technique (ART: own oocytes -OO- and egg donation -ED-) pregnancies.

Does a high or moderate nutritional supplementation affect the puberty and productive performance of Nellore heifers?

The effects of higher supplementation levels for young Nellore heifers fed tropical forages including their influence on puberty, need to be understood. This study investigated the influence of high and moderate supplementation levels on puberty onset and the productive performance of Nellore heifers. Thirty-six Nellore heifers (225 + 3.52 kg) were used in a completely randomized design, with three treatments: (I) no concentrate (control); (II) concentrate supplement at 4 g/kg body weight (BW); (III) concentrate supplement at 8 g/kg BW. Increased supplement level led to a linear increase in average daily gain (P &lt; 0.05). The high supplementation level (8 g/kg BW) had the highest proportion of corpus luteum presence (82% of heifers), compared to the 4 g/kg BW treatment group (67%) and the control group (33%; P &lt; 0.05). Our findings indicate that providing a high level of energy supplementation to Nellore heifers for approximately 100 d improves performance and increases the proportion of heifers that reach puberty

Effect of follicular ablation and gonadotropin priming on the recovery and quality of oocytes in Boran cows.

The objective of the study was to evaluate the effect of follicle ablation, exogenous FSH application, and different coasting time prior to ovum pick-up (OPU) on the number of follicles suitable for aspiration, oocyte quality, and cleavage rate in Ethiopian Boran cows. The experiment was carried out in three parts, (I) cows were synchronized using 500µg PGF2α given 11days apart. Cows were then subjected to a biweekly ovum pickup session before ovulation (n = 5) or starting day 7 after ovulation (n = 4) for 3weeks. (II) Cows were synchronized, and all visible follicles were ablated on the first days of overt estrus, and cows were grouped into those that received a divided dose of 350IU FSH (n = 5) or 175IU FSH (n = 5) over 3days. In both groups, OPU was carried out weekly starting 48h after the last FSH for 6weeks. (III) Protocol was similar to part II, but in group with 350IU FSH (n = 5), coasting period was increased to 72h. The covariates of follicles and oocyte were not affected (P > 0.05) by corpus luteum presence at OPU. The mean number of medium (7.36 ± 0.57) and large (8.28 ± 0.96) follicles were significantly higher (P < 0.05) in the group that received divided 350IU FSH. Similarly, the mean number of grade-1 (4.19 ± 0.24) and grade-2 (4.32 ± .27) oocytes, maturation rate (70.41%), and cleavage rate (47.5%) were significantly higher (P < 0.05) in the group that received 350IU FSH. COC quality was significantly (P < 0.05) influenced by coasting period. However, both maturation and cleavage rates were not affected by the coasting period. This study demonstrated that follicular ablation and treatment with FSH improves follicular population and oocyte recovery rate in Boran cows.

The influence of weaning age and biocholine supplementation to post-weaning growth and puberty in Brangus heifers

This experiment was conducted to determine the effect of earlier weaning in addition to biocholine supplementation on age at puberty of Brangus heifers. Brangus calves were randomized and divided into three weaning ages groups, at 30 (Hyper-early weaning; HW), 75 (Early weaning; EW) and 180 days (Conventional weaning; CW). Then, calves were supplemented using the additive Biocholine (BIO) or not (CON). Animals were subjected to puberty induction and the presence of estrus was observed for 7 days. In addition, transrectal ultrasonography was performed to assess the ovarian activity and the presence of corpus luteum to determine heifer puberty. We also evaluated the body weight (BW; Kg), hip height (HH; cm), thoracic perimeter (TP; cm) and BW:HH ratio during the experimental period. BIO group showed higher ADG (>226 g/day) when the animals were exposed to ryegrass pasture compared to CON (P < 0.05). We observed an interaction between weaning x biocholine and CW-BIO heifers showed greater HH more compared to CW-CON (P < 0.05). Overall, animals that have reached puberty at day 8 after puberty induction showed 331.0 ± 5.04 kg BW, 122.0 ± 0.56 cm HH and 165.4 ± 0.75 cm TP and 2.7 ± 0.03 BW:HH. At the time of ovulation detection, the heifers from the HW group had 32.1 kg BW, 3.93 cm HH and 0.18 cm BW:HH greater compared to CW (P < 0.05). The BIO supplementation together with ryegrass pasture, led to an increase in ADG weight throughout the evaluated period. We concluded that HW heifers showed an adequate body development throughout the experimental period until puberty appearance at the same age as others weaned groups.

Effect of repeated low doses of GnRH on follicular development and ovulation in anovulatory dairy cows with follicle growth to emergence size.

The aim of the study was to evaluate the effect of repeated low doses of GnRH agonist buserelin once a day for 5 days on follicle development and ovulation in anovulatory dairy cows with follicles growth only to emergence. The study was conducted on 71 anovulatory Polish Holstein Friesian cows. Anovulation with growth of follicles to emergence was defined as small ovaries with follicles of ≤ 5 mm in diameter and without corpus luteum on two examinations in a 7-10 day interval between 50-60 days after parturition. Cows were allocated to one of two group. Cows from group 1 (n = 58) received 0.4 μg of buserelin (Receptal, MSD, Poland) i.m. once a day for 5 days. Control cows from group 2 (n = 13) received saline. Ovarian structures were monitored weekly after the end of treatment by ultrasound for 4 weeks. The diameter of ovarian follicles on the ovaries was measured and recorded. Occurrence of ovulation was determined by the presence of corpus luteum. Overall, ovulation occurred in 46.6% (27/58) of cows treated with repeated doses of GnRH, while no corpus luteum was observed in the control group during the study period. There were significantly (p⟨0.05) more follicles 6-9 mm in diameter and 10-20 mm in diameter in cows treated with GnRH than in control cows. In conclusion, repeated low doses of GnRH analogue buserelin once a day for 5 days stimulate the development of ovarian follicles in anovulatory dairy cows with small ovarian follicles and led to ovulation in 46.6% of cows during 4 weeks after the end of the treatment.

Maternal and fetal haemopexin and α1-microglobulin concentrations in pre-eclamptic IVF pregnancies according to presence of corpus luteum at embryo transfer

Research questionDo pregnancies with corpus luteum show different maternal and fetal plasma concentrations of the scavenger proteins haemopexin and α1-microglobulin compared with pregnancies without corpus luteum in preeclampsia? DesignCase-control study of 160 singleton pregnancies: 54 naturally conceived, 50 by IVF after fresh embryo transfer or frozen embryo transfer (FET) in natural cycle (presence of corpus luteum) and 56 after fresh oocyte donation or FET in programmed cycles (absence of corpus luteum). Pregnancies were subclassified into normotensive, preeclampsia and severe preeclampsia cases. Heme-scavenger concentrations were measured by ELISA in maternal and cord plasma collected at delivery. ResultsAfter adjustment, maternal haemopexin was higher in IVF with corpus luteum than in naturally conceived pregnancies in normotensive (P = 0.038) and preeclampsia (P = 0.011) populations, and lower in preeclampsia for IVF pregnancies lacking corpus luteum compared with IVF with corpus luteum (P = 0.002). Maternal α1-microglobulin levels were higher in the absence of corpus luteum only in severe cases of preeclampsia compared with naturally conceived pregnancies (P = 0.014) and IVF with corpus luteum pregnancies (P = 0.041). In cord blood, haemopexin was higher in IVF with corpus luteum compared with naturally conceived pregnancies in preeclampsia (P = 0.039) and α1-microglobulin was higher in the group lacking corpus luteum compared with IVF with corpus luteum in the normotensive population (P < 0.001). ConclusionsThe physiological differences shown for these heme-scavengers between pregnancies after embryo transfer in the presence or absence of corpus luteum support the hypothesis that corpus luteum activity could influence perinatal outcomes. Future research is needed on whether applying potential strategies to develop a corpus luteum might reduce the perinatal complications associated with programmed cycles of IVF.