Day Of Estrus Research Articles

A neural circadian signal essential for ovulation is generated in the suprachiasmatic nucleus during each stage of the oestrous cycle.

What is the central question of this study? Is the suprachiasmatic nucleus the structure that generates the neural circadian signals that occur during every stage of the oestrous cycle, not only pro-oestrus, and are these signals essential for proper regulation of ovulation? What is the main finding and its importance? Transient inhibition of Na+ -dependent action potentials in the suprachiasmatic nucleus by tetrodotoxin microinjection at 14.00h inhibits ovulation irrespective of the stage of the oestrous cycle at which the procedure is performed. Microinjection of saline solution into the suprachiasmatic nucleus has a disruptive effect on ovulation that depends on the stage of the cycle at which it is administered. Reproduction is a highly timed process that depends on both the reproductive and circadian systems. The core oscillator of the latter resides at the suprachiasmatic nuclei (SCN) and it is pivotal for the regulation of the pro-oestrus pre-ovulatory surge of gonadotropins in females. There is evidence to suggest that this system may be involved in the regulation of neuroendocrine events that are essential for ovulation and that occur prior to pro-oestrus. We explored this possibility by transiently inactivating the SCN. Female rats were implanted with guide cannulas aimed at the SCN. After recovery of the oestrous cycle, animals were injected with tetrodotoxin (TTX), artificial cerebrospinal fluid (ACSF) or saline solution while freely moving. Injections were performed at 14.00h of each stage of the oestrous cycle. Animals were killed on the next predicted oestrus day, the number of ova shed was counted and intact rats at oestrus stage were used as absolute control. ACSF did not modify ovulation. Saline solution blocked ovulation in oestrus- and dioestrus-injected rats. Irrespectively of the stage of the oestrous cycle, TTX blocked ovulation. These results lead us to suggest that a neural circadian signal, pivotal for triggering the gonadotropin pre-ovulatory surge, arises from the SCN during the critical window of pro-oestrus. We also suggest that a similar signal, needed for the regulation of other events that are indispensable for proper regulation of ovulation, is also generated in this nucleus during the other stages of the cycle at a similar time.

VIP Promotes Recruitment of Tregs to the Uterine-Placental Interface During the Peri-Implantation Period to Sustain a Tolerogenic Microenvironment.

Uterine receptivity and embryo implantation are two main processes that need a finely regulated balance between pro-inflammatory and tolerogenic mediators to allow a successful pregnancy. The neuroimmune peptide vasoactive intestinal peptide (VIP) is a key regulator, and it is involved in the induction of regulatory T cells (Tregs), which are crucial in both processes. Here, we analyzed the ability of endogenous and exogenous VIP to sustain a tolerogenic microenvironment during the peri-implantation period, particularly focusing on Treg recruitment. Wild-type (WT) and VIP-deficient mice [heterozygous (HT, +/−), knockout (KO, −/−)], and FOXP3-knock-in-GFP mice either pregnant or in estrus were used. During the day of estrus, we found significant histological differences between the uterus of WT mice vs. VIP-deficient mice, with the latter exhibiting undetectable levels of FOXP3 expression, decreased expression of interleukin (IL)-10, and vascular endothelial growth factor (VEGF)c, and increased gene expression of the Th17 proinflammatory transcription factor RORγt. To study the implantation window, we mated WT and VIP (+/−) females with WT males and observed altered FOXP3, VEGFc, IL-10, and transforming growth factor (TGF)β gene expression at the implantation sites at day 5.5 (d5.5), demonstrating a more inflammatory environment in VIP (+/−) vs. VIP (+/+) females. A similar molecular profile was observed at implantation sites of WT × WT mice treated with VIP antagonist at d3.5. We then examined the ability GFP-sorted CD4+ cells from FOXP3-GFP females to migrate toward conditioned media (CM) obtained from d5.5 implantation sites cultured in the absence/presence of VIP or VIP antagonist. VIP treatment increased CD4+FOXP3+ and decreased CD4+ total cell migration towards implantation sites, and VIP antagonist prevented these effects. Finally, we performed adoptive cell transfer of Tregs (sorted from FOXP3-GFP females) in VIP-deficient-mice, and we observed that FOXP3-GFP cells were mainly recruited into the uterus/implantation sites compared to all other tested tissues. In addition, after Treg transfer, we found an increase in IL-10 expression and VEGFc in HT females and allowed embryo implantation in KO females. In conclusion, VIP contributes to a local tolerogenic response necessary for successful pregnancy, preventing the development of a hostile uterine microenvironment for implantation by the selective recruitment of Tregs during the peri-implantation period.

Influence of age and ovarian antral follicle count on the reproductive characteristics of embryo donor mares

BackgroundAge and antral follicle count (AFC) are related to fertility in cattle, but this information remains limited in mares.MethodsTo verify the influence of age and AFC on the reproductive characteristics...

Moosense pedometer activity and periestrual hormone profile in relation to oestrus in crossbred cattle

The objective of the study was to establish the characteristics of pedometer activity in crossbred cows (20) and to determine the relationships between the pedometer activity and the serum concentrations of periestrual hormones. Animals in oestrus were detected by trained personnel based on oestrus behaviour by visual observation twice daily. Further oestrus was detected by pedometer activity and it was confirmed by serum progesterone and estradiol concentration. Individual animal daily activity data were collected and transformed into hourly activity in Excel sheet and arranged for statistical analysis. The relationship of pedometer activity with E2, E2: P4 and progesterone level on the day of oestrus was determined. Pearson correlation analysis was performed using the statistical package SPSS (SPSS Inc. USA). Activity count per hour (ACPH) increased from 248.51±22.46, 312.51±37.16, 323.52±49.24 and 423.42±47.77 from -3 day, -2 day and -1 day of proestrus, respectively to estrus day. After estrus, the activity decreased from 313.76±46.62 and 271.36±36.06 on the 1st day and 2nd day of metestrus, respectively. A similar trend was observed for serum E2 and E2: P4 which increased from 3 days before estrus to reach a peak level on the day of estrus (31.40±2.34 pg/ml) and declined after that to the basal level (2 pg/ml) after estrus. Contrary to this, P4 concentration showed a decreasing trend from –3 day proestrus to estrus (0.46±0.05) and then a gradual increase after estrus day. ACPH showed positive correlation with estradiol concentrations (r = 0.34; P = 0.0779) and E2:P4 ratio (r=0.50; P=2.077) but, negative correlation with progesterone concentration on day of oestrus (r=–0.73; P=2.74). In conclusion, our results suggested that the concentration of E2, E2:P4 ratio and P4 concentration during proestrus and on the day of estrus are the important factors contributing the behavioral manifestation of estrus in terms of ACPH in crossbred cows.

腟内留置型黄体ホルモン製剤（CIDR）の留置開始日が黒毛和種繁殖牛の黄体機能ならびに発情発現日に及ぼす影響

腟内留置型黄体ホルモン製剤（CIDR）の留置開始日が黒毛和種繁殖牛の黄体機能ならびに発情発現日に及ぼす影響

Low invasive estrous synchronization protocol for wild animals: an example with melengestrol acetate in brown brocket deer (Mazama gouazoubira)

Deer are sensitive to stressful stimuli by handling and their reproductive physiology could be altered by these procedures, making it necessary to develop less invasive protocols for ART. Melengestrol acetate (MGA), a synthetic progestin administered orally, appears as an alternative for estrous synchronization protocols (ESP), such as reported in cattle. Firstly, we compared two MGA doses (0.5 and 1.0 mg/day/animal), which would have suppression effect in estrous behavior (EB). Eight females were randomly and equally distributed in Group 1 (G1) and Group 2 (G2), which received 0.5 and 1.0 mg/day/animal respectively for 15 days (D1 to D15). Two cloprostenol (CP) applications were performed on D0 and D11. Estrus detection (ED) was performed every day. All females from G1 displayed estrus during treatment period, whereas all females from G2 displayed estrus after treatment, suggesting a suppressive effect of 1.0 mg in the EB. Once the suppressive MGA dose (1.0 mg) was defined, we used this dose for assessing ESP. The same eight females received 1.0 mg/animal for eight days (D-8 to D-1), followed by 0.25 mg of estradiol benzoate on D-8 and 265 μg of CP on D0. Feces for fecal progesterone metabolites (FPM) measurement were collected from D0 until seven days after the last day of estrus. Seven females displayed estrus between 12 and 72 h after CP application, which was followed by a significant increase in FPM levels (except female MG6), suggesting the formation of corpus luteum. After ED, females were placed with a fertile male to assess the fertility of the protocol. Pregnancy was confirmed by ultrasound 30 days after mating in 3/6 individuals. Although the low effectiveness of MGA protocol, it should be considered as a promising alternative in deer ESP since this protocol has less stressful effect on the animal during reproductive management when compared to other ESP.

Increased number of large non-atretic follicles and co-dominance effects account for high litter sizes in Bonga sheep.

To understand the ovarian basis for prolificacy of Bonga sheep, a total of 31 ewes were selected based on litter size (LS) records and divided into two groups: High Prolificacy (HP) (n=20) with LS≥2 and Low Prolificacy (LP) (n=11) with LS=1. At a synchronized estrus, follicular dynamics were determined using transrectal ultrasonography. Plasma estradiol concentrations were also monitored. In total 27 ewes were observed in estrus being 9/11 LP (82%) and 18/20 HP (90%). On the day of estrus (day 0), the mean number of large follicles was higher (p<.05) in HP (1.78±0.19) than in LP (1.0±0.28) ewes. Prior to estrus, more (p<.05) medium follicles were visible for HP compared to LP ewes. Plasma estradiol concentrations were higher in HP compared to LP ewes (18.91±0.41 vs. 14.51±0.65pg/ml; p<.05) and similarly was ovulation number (2.3±0.15 vs. 1.28±0. 14; p<.05). Higher ovulation rates and litter size in Bonga sheep are evidenced by the previous presence of more large follicles and the existence of co-dominance effects as most likely medium follicles are selected to ovulate.

PSII-16 Thermal sensor-based multiple object tracking system for estrus detection in Korean native beef cattle

Abstract This experiment was conducted to improve estrus detection using a thermal sensor based on multiple object tracking system. A total of six Hanwoo (Korean native beef cattle, BW= 404 ± 58 kg) were used in this study. They were housed in a 5 × 10 m pen by three animals per replication. The total amount of moving distance and feed intake were measured before and after estrus period. The infrared thermography camera (FLIR A615, FLIR SYSTEMS, USA) was placed approximately 9 m above ground to take thermal images. The video files were analyzed to calculate moving distance of experimental animals by the tracking system which was developed by our previous research. Each animal in a pen was tracked on thermal video files, and then moving distances were calculated by topographic surface-based object segmentation, velocity weight, and the river-bed refinement. Feed intake was calculated every day at 0900 by weighing residual feed. On the day before estrus, the total moving distance of experimental animals was 6,434 m (Pen 1= 6,873 m, Pen 2= 5,995m), whereas it was 15,121 m (Pen 1= 17,434 m and Pen 2= 12,808 m) on the estrus day, showing 2.35 times increase (P &amp;lt; 0.05) in moving activity. Feed intake was decreased (P &amp;lt; 0.05) by 11% on estrus day (29.4 vs. 26.1 kg). A decrease in feed intake and an increase in movement of beef cattle on the estrus day, were obvious signs that have been well documented not only in previous researches and but empirical knowledge. In this study, however, the exact moving distance of Korean native beef cattle was calculated by the thermal imaging video tracking system. Therefore, this multiple object tracking system could be applied in practice to detect estrus of beef cattle.

Evaluation of anti-Mullerian hormone, antral follicle count and progesterone concentration during estrous cycle in Murrah buffaloes

An experiment was conducted to study the anti-Mullerian hormone (AMH) concentration, antral follicle count (AFC) and progesterone (P4) concentration during estrous cycle in Murrah buffaloes. Seven animals of 5–10 years were selected for the study. All the animals were synchronized as per the ovsync protocol and the pair of ovary of each animal was scanned by ultrasonography on 0, 3rd, 7th, 11th, 14th, 17th and 21st day of estrous cycle. Blood was collected on the same day to evaluate serum AMH and P4 concentration. The nonsignificant difference was observed in antral follicle count of 3–5 mm, 5–8 mm and total follicles count (&gt; 3 mm), whereas, significantly lower mean values of &gt;8 mm of antral follicles were recorded on the day of estrus (0.14 ±0.14) as compared to 3rd, 7th, 11th, 14th, 17th and 21st day of estrous cycle. The significant individual variation was recorded in average mean of 3 - 5 mm and total antral follicle count (&gt;3 mm). However, the difference for 5 - 8 mm and &gt;8 mm was nonsignificant. The positive correlation of low and high antral follicle count was observed in the present study. Two animals of low antral follicle count remained non pregnant and two animals showed 3 follicular waves during estrous cycle. The nonsignificant difference was recorded in AMH concentration during estrous cycle, whereas, individual variation in AMH concentration differ significantly. The progesterone concentration showed significant increase and decrease in values according to the stages of estrous cycle.

162 Detection of ovulation disorders and normal ovulation using wireless sensors of ventral tail surface temperature and neck acceleration data in Japanese Black cows

The present study aimed to clarify the possibility of detection of ovulation disorders and normal ovulation in Japanese Black cows using wearable wireless sensors based on continuous measurements of body surface temperature (ST) and neck acceleration data. For cows with normal ovulation (n=19, 8.5 years old, 476.2kg), controlled internal drug release (CIDR) and gonadotrophin-releasing hormone were administered on arbitrary days of the oestrous cycle (Day −10), and oestrus was induced by CIDR removal and prostaglandin F2α administration (Day −3). Ovulation (Day 0) was induced by gonadotrophin-releasing hormone administration on estimated oestrus day (Day −1) and was detected based on the disappearance of ≥8mm follicles using ultrasonography at 1- to 2-h intervals. For cows with spontaneous ovarian cysts (n=11, 8.6 years old, 471.2kg), oestrus and the next day were defined as Days −1 and 0, respectively. Plasma concentrations of progesterone (P4) and oestradiol-17β (E2) were measured on Days −9, −6, −2, −1, 0, 1, 5, and 8. The body ST sensor was attached to the ventral tail base (Day −16), and ST was measured every 10min for 24 days. For analysis of ST, after extracting hourly maximum ST values, the values were expressed as residual ST (RST; ST − mean ST for the same hour on the previous 3 days) for removal of circadian rhythm (Miura et al. 2017 Anim. Reprod. Sci. 180, 50-57; https://doi.org/10.1016/j.anireprosci.2017.03). The acceleration sensor (Farmnote Color, Farmnote Inc.) was attached to the neck (Day −16). Hourly oestrus level (amount of oestrus activity) was obtained from the amount of activity; the difference between the residual oestrus level (REL; same calculation as RST) and measured values of each day was used. To identify RST and REL of cows with normal ovulation and cows with ovarian cysts, the mean values and standard deviations for the same hours for 3-7 days before oestrus were calculated. Mean RST and REL for 3-7 days before oestrus were assumed according to the normal distribution. The 95% confidence range was determined using×1 standard deviation of all hours. Values over the 95% confidence range for ≥5h were considered to be different from the mean 4 days and the 5% level. For RST, no difference was found in both groups due to the large influence of environment, particularly low temperature. However, for REL, a difference was indicated for oestrus in all cows (P&amp;lt;0.05). A large peak of REL appeared once on oestrus (&amp;gt;14.4 REL for 20h) in normal cows, and three peaks occurred in &amp;lt;21 days (&amp;gt;16.2 REL for 21, 15, and 15h) in cows with ovulation disorders (P&amp;lt;0.05). The REL rapidly increased following peaking E2 and decreasing P4 to oestrus (Day −1) in normal cows. In cows with an ovulation disorder, REL increased on oestrus; however, E2 and P4 remained high and low stable to oestrus, respectively. In conclusion, oestrus activity and the characteristics of normal cows and those with an ovulation disorder can be detected by the neck acceleration sensor using the correction value. This research was supported by The Research Project for the Future Agriculture Production Utilising Artificial Intelligence.

115 Invivo confocal laser endomicroscopy visualisation of fresh and frozen bull spermatozoa in the genital tract of dairy heifers

Fertility in cattle includes the ability of the uterus to provide the appropriate environment for pregnancy success, including the transport of spermatozoa before fertilization. Confocal laser endomicroscopy technology (Cellvizio) has been previously used in small ruminants to visualise labelled spermatozoa invivo in the uterine horns of ewes (Druart et al. 2009 Reprod. 138, 15-53). Nevertheless, to the best of our knowledge, no invivo study has reported a live visual analysis of the behaviour of spermatozoa in the bovine uterus upon AI. The aim of this study was to develop an experimental procedure to label bull spermatozoa and to visualise their progression in the uterine horns of dairy cows, using Cellvizio and uterine cervix catheterization. Fresh ejaculated bull spermatozoa were double-labelled with octadecyl rhodamine B chloride and MitoTracker Green FM dyes before dilution and freezing processing. At each step of the process, semen quality was evaluated with a semen quality analyzer (SQA-V b, Medical Electronic System) and compared to nonlabelled bull reference semen. The specificity of the labelling was validated invitro. We also developed a specific device to insert the Cellvizio fibre probe into the genital tract, in order to image vagina, cervix, and uterine body, as well as the proximal, middle, and distal parts of the uterine horn, including the utero-tubal junction (UTJ), before and after AI with fresh and frozen labelled spermatozoa. Then, 10 heifers were oestrus synchronized. Video sequences were recorded at oestrus (n=5), just before AI, at the time of AI (7-12h after the onset of oestrus), 30 and 120min after AI, and 14 days after oestrus (n=5; luteal phase), to investigate the effect of the steroid-primed uterine environment on the distribution and progression of spermatozoa in the genital tract. Using our approach, labelled spermatozoa were detected (1) at the day of oestrus and 14 days after oestrus, (2) in the uterine body at the time of AI, (3) in various parts of the genital tract 30min after AI, and (4) in the UTJ, the cervix, and the vagina 120min after AI. In addition, labelling the spermatozoa did not alter the fertilizing capacity: 4 of the 5 oestrus females were pregnant at Day 35. Additionally, an IVF test showed a blastocyst rate of 45.8% for labelled semen vs. 39.4% for the control group (Carvalho et al. 2017 Reprod. 154, 695-710). In conclusion, our study provides a method to phenotype in situ the transport of spermatozoa in the genital tract of heifers. Further investigations are in progress to optimize video quality, to develop an algorithm for an automatic analysis (spermatozoa count, speed, and path) of the recorded sequences.

A comparative analysis of gene expression induced by the embryo in the caprine endometrium.

Transcriptomics is an established powerful tool to identify potential mRNAs and ncRNAs (non‐coding RNAs) for endometrial receptivity. In this study, the goat endometrium at estrus day 5 (ED5) and estrus day 15 (ED15) were selected to systematically analyse the differential expressed genes (DEGs) what were induced by the embryo. There were 1,847 genes which were significantly differential expressed in endometrium induced by the embryo at ED5, and 1,346 at ED15 (p‐value < .05). Secreted phosphoprotein 1 (SPP) was the responsive genes for embryo in the goat endometrium during estrus cycle, neurotensis (NTS) and pleiotrophin (PTN) were the responsive genes for embryo in the goat endometrium at ED5, Testin (TES) and Phosphate and Tension Homology Deleted on Chromsome ten (PTEN) at ED15. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes (KEGG) analysis revealed cytoplasm and Endocytosis were indispensable for the endometrium development in dairy goat. In a word, this resulting view of the transcriptome greatly uncovered the global trends in mRNAs expression induced by the embryo in the endometrium of dairy goats.

Associations between motion activity, ketosis risk and estrus behavior in dairy cattle

Ketosis (acetonaemia) is a metabolic disorder that occurs in cattle when energy demand exceeds energy intake and results in a negative energy balance. The course of the disease often starts with a subclinical phase, so early detection is crucial for decisive strategies. The aim of this study was to determine whether daily motion activity could be used as an indicator of subclinical ketosis in early lactation and to evaluatethe effect of subclinical ketosis on activity at estrus.The study was carried out on a 75-cow dairy farm over 6 months. Data were collected from 48 cows between day 0 and day 70 post-partum. Beta-Hydroxybutyrate (BHB) concentrations were evaluated in milk samples using rapid on-site ketosis tests. A test was considered positive at a concentration of >100 μmol/l. The animals were divided into two groups: group ‘Healthy’ (H) and group ‘Ketosis’ (K). Once the on-site test was positive, the cows were assigned to group K. Progesterone concentrations were evaluated in milk by photometric detection of the colour reaction of a competitive, heterologous enzyme immunoassay (EIA). Each drop from ≥0.3 ng/ml to <0.3 ng/ml with a subsequent increase to ≥0.3 ng/ml was considered estrus. Daily milk yield, concentrate intake and motion activity were recorded from a computerized dairy management system with the associated software (DairyPlan C21).Animals in group K had lower average daily activity levels than animals in group H. In this study, statistically significant reduced motion activity in animals in group K was observed on days 6–12 post-partum (P < 0.001, χ² test) compared with the herd mean daily motion activity. Furthermore, a significant association could be found between motion activity and group affiliation (logistic regression models). The sensitivity of the detection of cows at risk for ketosis was 81.8 %, and the specificity was 65.4 %, retrospectively determined by their activity behaviour. The mean motion activity on the day of estrus was significantly (P < 0.05) lower in animals in group K than in those in group H.This method may help to establish a future early warning system for the risk of ketosis in dairy cows. Thus, cows at risk may be identified for further targeted diagnostics and for selective treatment procedures. This study confirms the already reported lasting effect of subclinical ketosis on reproductive efficiency.

Social Behavior of a Reproducing Pair of the Philippine Tarsier (Tarsius syrichta) in Captivity

ABSTRACT Social interactions of the nocturnal primates are not well studied. One of the species for which social behavior is scarcely known is the Philippine tarsier (Tarsius [= Carlito] syrichta). We observed a reproducing pair of captive individuals over two mating seasons for two consecutive years. The tarsiers spent approximately 4% of their activity budget on social interactions; ca. 20% of time in 0–1 m proximity to each other; and shared sleeping sites for half of the study time. The majority of the animals’ social interactions were peaceful: affiliative and sexual (83%), and the smallest component of the behavior was agonistic (17%). We witnessed two copulation events (one per estrus day), each lasting ca. 5 min, and both occurring just after waking. We revealed temporal – nightly and hourly – fluctuations in the frequency of social interactions, in the distances the individuals spent from each other and in the number of vocalizations. The results present the first assessment of the social behavior of the Philippine tarsier, much needed to improve the captive breeding management for this highly sensitive species threatened with extinction.

In rats with estradiol valerate-induced polycystic ovary syndrome, the acute blockade of ovarian \u03b2-adrenoreceptors improve ovulation

BackgroundPolycystic ovary syndrome is characterized by hyperactivity of the ovarian sympathetic nervous system, increases in the content and release of norepinephrine, as well as decreases in the number of β-adrenoreceptors. In the present study, β-adrenoreceptors in the ovaries of rats with polycystic ovary syndrome were blocked and analyzed the resultant effects on ovulation, hormone secretion and the enzymes responsible for the synthesis of catecholamines.MethodsAt 60 days of age, vehicle or estradiol valerate-treated rats were injected with propranolol [10− 4 M] into the ovarian bursas on oestrus day. The animals were sacrificed on the next day of oestrus, and the ovulation response, the steroid hormone levels in the serum and the immunoreactivity of tyrosine hydroxylase and dopamine β-hydroxylase in the ovaries were measured.ResultsIn animals with the induction of polycystic ovary syndrome and β-adrenoreceptor blocking, ovulation was restored in more than half of the animals and resulted in decreased hyperandrogenism with respect to the levels observed in the estradiol valerate-treated group. Tyrosine hydroxylase and dopamine β-hydroxylase were present in the theca cells of the growing follicles and the interstitial gland. Injection of propranolol restored the tyrosine hydroxylase and ovarian dopamine β-hydroxylase levels in rats with polycystic ovary syndrome induction.ConclusionsThe results suggest that a single injection into the ovarian bursas of propranolol, a nonselective antagonist of β-adrenoreceptor receptors, decreases the serum testosterone concentration and the formation of ovarian cysts, improving the ovulation rate that accompanies lower levels of tyrosine hydroxylase and dopamine β-hydroxylase in the ovary.

Reproductive performance of goats treated with free gonadorelin or nanoconjugated gonadorelin at estrus

The reproductive performance of goats that received a GnRH analog (gonadorelin) fabricated with or without chitosan-sodium tripolyphosphate (TPP) nanoparticles on the day of estrus (day 0) was evaluated. The chitosan-TPP polymer was conjugated with gonadorelin using an ionic gelation method. Thirty-three multiparous Zaraiebi goats were synchronized for estrus with 2 intramuscular (im) injections of 125 μg prostaglandin F2α 14 d apart. Goats showing signs of estrus were divided equally into 3 experimental groups and received a single im injection of 1 mL physiological saline (placebo; control), 50 μg/mL gonadorelin (GnRH), or 12.5 μg (quarter of GnRH dose)/mL chitosan-TPP–conjugated gonadorelin nanoparticles (NGnRH). Each goat underwent ultrasound imaging of their ovaries at day 0 and at day 10 after mating, and pregnancy was diagnosed 28 and 45 d after mating. The concentrations of estradiol (E2) and progesterone (P4) were determined at day 0 and at days 7, 14, 21, and 42 after mating. NGnRH size, polydispersity, and zeta potential were 93.91 nm, 0.302, and 11.6 mV, respectively. Chitosan-TPP nanoparticles showed 91.2% entrapment efficiency for GnRH. No differences in estrus rate, interval to estrus, or ovarian structure at day 0 were observed among the experimental groups, but the GnRH and NGnRH treatments significantly decreased the duration of estrus compared with the control. At day 10 after mating, both GnRH and NGnRH increased (P = 0.011) the number of corpora lutea compared with the control. Treatment with GnRH increased (P = 0.023) serum E2 concentrations from day 7 to 42 after mating compared with NGnRH and control treatments. The highest (P = 0.043) serum P4 concentration was observed in the GnRH group, followed by the NGnRH and control groups. The increase in serum P4 concentration started earlier a on day 7 in the GnRH group but later on day 14 in the NGnRH group. Compared with the control, GnRH resulted in a higher (P = 0.041) P4-to-E2 ratio, followed by NGnRH. Both gonadorelin treatments significantly increased the twinning rate, the number of embryos at days 28 and 42, and prolificacy and decreased pregnancy losses compared with the control. In conclusion, the administration of GnRH at the time of estrus improved the prolificacy of goats by increasing both the ovulation rate and the number of embryos. In addition, the nanoformulation developed in this study allowed a 75% reduction in the conventional dose of gonadorelin without affecting the fertility and prolificacy of goats, indicating the bioavailability of the reduced GnRH dose after conjugation with developed nanoformula.

Exogenous kisspeptin (kp-10) resumes cyclicity in postpartum anestrus mithun cows

Present study was conducted to assess the effect of exogenous kisspeptin administration on estrus induction, Kiss1gene expression, endocrinological profiles and follicular development in post partum (PP) anestrus mithun cows. Animals who failed to resume cyclicity after day 90–100 of parturition were selected. Experimental cows were examined thoroughly through per-rectal as well as ultrasonograpic examination to confirm the anestrous status. PP anestrous healthy mithun cows (12), aged 5–6 years (body condition score: 5–6 of 10) were selected with uniform anestrus status and randomly divided into 2 groups namely treatment (Gr I) and control (Gr II), each group consist 6 cows. Anestrus cows in Gr 1 were injected with kisspeptin @ 1.30 μg per kg body weight at 3 day interval for 21 days after 90–100 days of post parturition whereas in control group, normal saline was injected as placebo. Blood samples were collected on the days of injection and at estrus in both the groups. Trans-rectal ultrasonography was done at 3 days interval till onset of estrus and ovulation to study the follicular development. Exogenous kisspeptin administration caused significantly early resumption of cyclicity in treatment as compared to control (24.64±10.43 vs 66.56±14.66 days) and significantly increased kiss1 and GPR54 mRNA expression in treatment as compared to control on the day of estrus (1.943±0.29 vs 0.424±0.062 and 1.84±0.31 vs 0.416±0.082, respectively). Similarly, circulating level of estradiol and follicle stimulating hormone (FSH) increased gradually after exogenous administration of kisspeptin, which reached peak on the day of estrus in treatment group (25.36±1.27 pg/ml and 15.65±1.22 ng/ml, respectively) whereas no significant difference was observed between days of treatment in control group except on the day of estrus (11.29±1.76 pg/ml and 9.86±1.06 ng/ml, respectively). Level of estradiol and FSH on the day of estrus was significantly higher in treatment as compared to control whereas non-significant difference was observed in plasma progesterone concentration. Number of medium and large follicles increased in treatment whereas only small follicles were observed in control group. Improved endocrinological profiles, follicle development and kiss gene profiles in post partum anestrous mithun cows following exogenous kisspeptin indicates that kisspeptin inducted or resumed the cyclicity in early.

Comparison of pregnancy rates with transfer of in vivo produced embryos derived using multiple ovulation and embryo transfer (MOET) with in vitro produced embryos by somatic cell nuclear transfer (SCNT) in the dromedary camel (Camelus dromedaries)

In the present study, there was comparison of pregnancy rates with transfer of in vivo-produced embryos using multiple ovulation and embryo transfer (MOET) with in vitro-produced embryos by somatic cell nuclear transfer (SCNT) in dromedary camels. In vivo-produced embryos were collected from donors after super-stimulation of follicular development on day 7 after ovulation, while in vitro-derived embryos were produced using SCNT from in vivo-matured oocytes collected from camels after follicular development super-stimulation. As a result of estrous synchronization, all recipient camels for both groups were 1 day earlier in stage of estrous cycle than developmental status of embryos at the time of transfer. The animals into which embryos were transferred were monitored at 7-day intervals after embryo transfer for signs of pregnancy based on response to presence of a male and there was ultrasonic confirmation on days 35 and 60 subsequent to day of estrus in recipient animals. A greater proportion of recipients (P < 0.05) were considered pregnant based on response to male presence when there was transfer of MOET-(76.8 ± 3.2) compared with SCNT- (26.4 ± 2.4) derived embryos on day 14. There was no difference in pregnancy losses in subsequent weeks until day 60 between groups. There were also no differences in calving rates of females in which MOET- (91.7%) and SCNT- (93.3%) derived embryos were transferred. These results indicate pregnancies at day 60 with SCNT-derived embryos are sustained for the remainder of gestation periods similar to when there was transfer of MOET-derived embryos in dromedary camels.

Effect of bull biostimulation on the oestrous behaviour of pubertal Sahiwal (Bos indicus) heifers

The study was conducted to determine effects of biostimulation of Sahiwal heifers through fenceline bull contact and fenceline combined with direct bull contact on oestrous behaviour when there was ovulation occurring in the absence of behavioural oestrus (“silent oestrus - SE) and overt behavioural oestrus (OBE). Prepubertal Sahiwal heifers were allotted to three treatments (T0, T1, T2, n = 8 heifers/treatment). In the T0 group, there was no bull exposure; in T1, exposure to a bull through fenceline contact for 24 h and in T2, exposure to a bull as in T1 along with direct bull contact with another bull for a 6 -h period daily. The oestrous behaviours were recorded on day (d) −3, −2 and −1 (prior to oestrus), d 0 (day of oestrus) and d +3, +2 and +1 (post-estrus). With both SE and OBE, the mean frequency of sniffing, micturition, chin resting and standing to be mounted differed (P < 0.05) from d −2 to d +1 among treatment groups. The mean times devoted to eating, ruminating and lying during SE and OBE were less (P < 0.05) on d-1 and d 0 in heifers of all three groups than the respective values on reference days in both T1 and T2 groups. Biostimulation of Sahiwal heifers with bull exposure, therefore, resulted in greater expression of oestrous behaviour than in non-exposed heifers during the periods around when there was SE and OBE.

Synchronization with controlled internal drug release (CIDR) and prostaglandin F2α (PGF2α) influences oxidant/antioxidant biomarkers and mineral profile in summer-stressed anoestrous buffalo (Bubalus bubalis)

During the summer season, high ambient temperature in tropical and subtropical countries exposes buffaloes to oxidative stress that have antigonadotropic and antisteroidogenic effects. Uses of hormonal therapy can improve the state of ovarian inactivity caused by heat stress and cause anoestrous buffaloes to come into oestrus and successfully achieve pregnancy. Therefore, this study was designed to detect the role of oxidative stress in production of the anoestrous state in summer heat stressed buffaloes and the effects of treatment by Controlled internal drug release (CIDR) in solving of this problem. Also it monitored the changes in Oxidant/antioxidant biomarkers and mineral profile before and after the treatment.Forty buffaloes with no signs of oestrus for more than 120 days after calving were selected. The animals were divided into two groups: the first group (group I, n = 25) was subjected to treatment with CIDR, while the second group (group II) received no treatment and was considered the control group (n = 25). Blood samples were collected before treatment, after treatment and after 45 days of oestrus. The serum level of TAC, MDA, NO, ascorbic acid (vitamin C), P, Cu and Zn were measured. The results showed that 80% of treated buffaloes came into oestrus. The conception rate was 75%. TAC concentrations were significantly higher in group I than in group II. There were significant decreases in the mean values of MDA, NO and ascorbic acid in the buffaloes in oestrus, but these values increased when the buffaloes became pregnant. In contrast there were no significant differences in the mean values of MDA, NO or ascorbic acid in the buffaloes that came into oestrus but failed to conceive. The mean serum P, Cu and Zn values were significantly increased (P < 0.05) in the buffaloes that came into oestrus compared to the control animals. The levels of P and Zn significantly increased when the buffaloes became pregnant and remained unchanged when they failed to conceive. In conclusion, known physiological and pathological variations in the oxidant/antioxidant parameters and mineral profile of summer anoestrous buffaloes may help to understand this problem of infertility.