Onset Of Estrus Research Articles

The enriched Y-bearing sperm combined with delayed fixed-time artificial insemination for obtaining male Simmental crossbred offspring.

Background and Aim:The production of male calf beef cattle is an agricultural innovation needed to increase the farm’s productivity as a provider of meat sources. This study aimed to determine the sex ratio of the offspring of cows inseminated with Y-bearing sperm enriched by Percoll density gradient centrifugation and swim-up, combined with delayed fixed-time artificial insemination (FTAI).Materials and Methods:Ejaculates of Simmental bulls were divided into four equal portions and grouped as T0 (control, non-sexed semen), T1 and T2 were sexed semen using Percoll density gradient centrifugation three and five levels, respectively, and T3 was sexed semen using swim-up. After the sex was sorted, the semen was diluted in a tris-egg yolk extender, packaged in French mini-straws containing 50 million live sperm cells, and frozen. Pre-sexed, post-sexed, and post-thawed spermatozoa were evaluated based on progressive motility, viability, intact plasma membrane, and abnormality. The post-thawed semen of T0 was artificially inseminated to recipient cows at 12 h after onset of estrus (not delayed FTAI). Meanwhile, the delayed FTAI was conducted 18-20 h after onset of estrus using the T0, the best of T1 and T2, and the T3 post-thawed semen.Results:The Percoll density gradient centrifugation reduced motility, viability, and intact plasma membrane but increased sperm abnormalities. Meanwhile, the swim-up process increased motility, viability, and intact plasma membrane of sperm cells but decreased sperm abnormalities. Post-thawed semen decreased motility, viability, and intact plasma membrane of sperm cells but increased sperm abnormalities. The sex ratio of the Simmental crossbred offspring was 96.08% and 100% in T1 and T3, respectively, compared to 48.25% and 67.39% in T0 not delayed and delayed FTAI, respectively.Conclusion:The Percoll density gradient centrifugation and swim-up methods are prospective for obtaining male offspring.

Impact of adrenocorticotropin hormone administration on the endocrinology, estrus onset, and ovarian function of weaned sows.

Chronic stress affects the reproductive health of mammals; however, the impact of adrenocorticotropin hormone (ACTH) level elevation during chronic stress on the reproduction of weaned sows remains unclear. In this study, nine weaned sows with the same parturition date were randomly divided into control group (n = 4) and ACTH group (n = 5). Each group received intravenous administration of ACTH three times daily for 7 days. Blood samples were collected every 3 h after injection. A radioimmunoassay was used to measure the concentrations of cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P4) and estradiol-17β (E2) in the blood. Estrus was determined according to changes in the vulva and the boar contact test. The mRNA expressions of glucocorticoid receptor, FSH receptor, LH receptor (LHR) in the corpus luteum (CL) were detected by qRT-PCR. The results showed that ACTH administration substantially delayed the initiation of estrus and the pre-ovulatory LH peak. The sows of control group ovulated within 10 days and the ovulation rate was 100%, while it was 60% in the ACTH group. Two sows of ACTH group showed pseudo-estrus. The E2 concentrations significantly decreased in the ACTH group at 36 h, 42 h and 66 h of the experimental period. The P4 concentrations in the ACTH group significantly decreased at 132, 138, and 147 h of the experimental period. ACTH significantly reduced the LHR mRNA expression in CLs. In conclusion, long-term repeated ACTH administration affects the endocrinology, estrus onset, and ovarian function of weaned sows.

A Comparative Study on the Reproductive Performance of South African Indigenous Sheep Breeds Following Oestrus Synchronization

The aim of the study was to compare the effect of age and live body weight on the oestrus response, duration, pregnancy rate and lambing rate among South African indigenous sheep breeds (Zulu sheep = 36, Bapedi sheep = 26, Damara sheep = 10 and Namaqua Afrikaner sheep = 9). Control Intravaginal Drug Release Dispensers (CIDR’s) were inserted into the vagina for 10 days. The twitching of tail and standing to be mounted in the presence of the teaser ram were most targeted signs of oestrus. Data were subjected to an appropriate analysis of variance (ANOVA). The scores were subjected to 1:1 Frequency table and a Chi-Square (χ²) test for the equal proportions test. One Bapedi ewe loss CIDR before removal date hence was removed from the experimental animals. All Namaqua Afrikaner (100%) ewes responded to the synchronization protocol with the longest oestrus duration (70.7±7.2 h). However, Namaqua Afrikaner sheep scored the lowest rate for conception (44%) and lambing (44%). No significant different (P>0.05) observed for the onset of oestrus among the breeds. Four years old ewes responded better to oestrus synchronization than ≤3, 5 and ≥6 years. Nevertheless, ewes that were ≥6 years old had higher conception rate (94%) and lambing rate (84%). Zulu sheep had higher (89%) lambing rate than Damara (60%) sheep and Namaqua Afrikaner (44%) sheep. Lighter ewes had higher conception (83%) and lambing rate (90%) than heavier (77 and 64%) and moderate (68 and 78%) weights, respectively. In conclusion, Zulu sheep were more fertile than other South African indigenous breeds following oestrus synchronization. On the other hand, young ewes (≤3 years) produced heavier lambs and weaning weight but had higher mortality rate due to inexperience.

A 24-Year Record of Female Reproductive Dynamics in Two Sympatric Mouse Lemur Species in Northwestern Madagascar

Seasonal reproduction is widespread among primates but the degree of reproductive synchrony and plasticity can vary, even between closely related species. This study compares the dynamics of female reproductive seasonality in two mouse lemur species, Microcebus murinus and M. ravelobensis, in Ankarafantsika National Park, Madagascar, across 24 years. We collected 4321 records of female reproductive state from 1033 individual females (319 M. murinus, 714 M. ravelobensis). The analyses revealed disparate reproductive schedules: While female M. murinus showed high degrees of reproductive synchrony throughout all years, leading to the production of two successive litters, the seasonal onset of estrus (= reproductive activation) in female M. ravelobensis was more flexible than in M. murinus, starting 2-4 weeks earlier, varying by up to 4 weeks between years, and being less synchronized. M. ravelobensis females became reproductively active later in years with more rainfall, in particular rain in February, but the timing of reproductive activation was not related to differences in temperatures. The likelihood of early conception was significantly lower in M. ravelobensis than in M. murinus. This was partly due to delayed reproductive activation in young animals, and a lower likelihood of early conception for females with low body mass in M. ravelobensis. Our results suggest high, adaptive reproductive plasticity in M. ravelobensis that may enable individuals to respond flexibly to yearly environmental changes and expand the reproductive period under favorable conditions. These species differences in reproductive schedules may be the result of the divergent evolutionary histories of the two mouse lemur species in different parts of Madagascar.

The Effect of Insemination Time, Season and Insemination Method on Calf Gender in Holstein Cattle

The aim of this article is to determine the effect of insemination time, season and insemination method on calf gender in cattle. In the study, 792 records of inseminations and calving data between 2010-2019 were evaluated. The onset of estrus was determined based on mounting behavior. Inseminations were carried out between 0-6, 6-12, 12-18 hours after the onset of estrus. At the same time, inseminations were evaluated according to the seasons. Of the inseminations, 582 were artificial insemination and 210 were natural insemination. While insemination time and insemination method had no effect on calf gender, seasonal effect was found to be significant. Keywords: Holstein, Insemination Time, Gender DOI: 10.7176/JSTR/7-10-03

Effects of FecB Mutation on Estrus, Ovulation, and Endocrine Characteristics in Small Tail Han Sheep.

The Booroola fecundity gene (FecB) has a mutation that was found to increase the ovulation rate and litter size in Booroola Merino sheep. This mutation is also associated with the fecundity of small-tail han (STH) sheep, an important maternal breed used to produce hybrid offspring for mutton production in China. Previous research showed that the FecB gene affects reproduction in STH sheep, based on litter size records. However, the effects of this gene on estrus, ovulation, and endocrine characteristics in these sheep remain unclear. Here, we analyzed the traits mentioned earlier and compared them among the three FecB genotypes of STH ewes using estrus synchronization. Overall, 53 pluriparous ewes were selected from among 890 STH ewes and subjected to FecB genotyping for experiments to characterize estrous and ovulation rates. FecB heterozygous (+B) ewes presented an earlier onset of estrus (42.9 ± 2.2 h) and a shorter estrous cycle (17.2 ± 0.2 days) (P ≤ 0.05). The ovulation rates increased with the increasing copy number of the B allele (P ≤ 0.01). Ovulation time showed no significant differences among the three FecB genotypes. The serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone, estrogen (E2), and progesterone (P4) were measured in 19 of the ewes. Serum concentrations of E2 and FSH dramatically varied around the time of behavioral estrus. In FecB mutant homozygous (BB) ewes, E2 concentration had two peaks, which were higher (P ≤ 0.05) than those of ++ genotypes. FSH concentration of BB ewes was higher (P ≤ 0.05) than that of the ++ ewes just after estrus. The expression of the estrogen receptor 1 (ESR1) gene in the +B genotype was higher than in the other genotypes. Based on the data for the reproductive performance of STH ewes with the three FecB genotypes, our study suggests that the development of follicles in ewes with the B allele is dependent on the response to FSH regulated by E2 in the early stage. +B ewes, exhibiting moderate ovulation and litter size and a shorter estrous cycle, can be highly recommended in sheep crossbreeding systems for commercial mutton production. Moreover, this study provides useful information to conserve better and use the genetic resources of STH sheep in China.

A Short-Term Altrenogest Treatment Post-weaning Followed by Superovulation Reduces Pregnancy Rates and Embryo Production Efficiency in Multiparous Sows.

Although embryo transfer (ET) is a biotechnology ready for the swine industry, there are factors to be solved, the availability of embryo donors as one. Multiparous sows as donors ought to be considered since weaning is a natural and efficient method for estrus synchronization. In addition, superovulation treatments at weaning are effective in increasing the efficiency of donor embryo production. However, ET programs typically require more donors than those available from a single weaning, imposing grouping several weanings to establish a batch for ET. Since short-term administration of Altrenogest is effective in delaying estrus after weaning without effects on ovulation and embryo development, we investigated how Altrenogest combined with superovulation would affect reproductive parameters and embryo quality and quantity of weaned multiparous donor sows. The sows were administered Altrenogest from the day of weaning for 14 (SS-14 group; N = 26), 7 (SS-7 group; N = 31) and 4 (SS-4 group; N = 32) days. The sows were superovulated with eCG 24 h after the last administration of Altrenogest and with hCG at the onset of estrus. Sows not treated with Altrenogest that were superovulated with eCG 24 h post-weaning and hCG at the onset of estrus (SC group; N = 37) and sows with natural estrus after weaning (C group; N = 34) were used as control groups. The percentage of sows showing estrus within 10 days was not affected by the treatment, but the interval from Altrenogest withdrawal to estrus was longer (P < 0.05) in the SS groups than the interval from weaning to estrus in the controls. SS treatments increased (P < 0.05) the percentage of sows with ovarian cysts and the development of polycystic ovaries. The pregnancy and the fertilization rates, and the overall embryo production efficiency were also negatively affected by the SS treatments (P < 0.05). Interestingly, almost 70% of the structures classified as unfertilized oocytes or degenerated embryos in sows from the SS groups were immature oocytes. In conclusion, although superovulation of weaned sows was highly efficient, short-term administration of Altrenogest in combination with superovulation had negative effects on most of the reproductive parameters assessed, particularly affecting the overall efficiency of pregnancy and embryo production.

Vitrification Effects on the Transcriptome of in vivo-Derived Porcine Morulae.

Despite the reported promising farrowing rates after non-surgical and surgical transfers of vitrified porcine morulae and blastocysts produced in vivo (range: 70–75%), the pregnancy loss is 5–15 fold higher with vitrified than with fresh embryos. The present study aimed to investigate whether vitrification affects the transcriptome of porcine morulae, using microarrays and RT-qPCR validation. Morulae were obtained surgically from weaned sows (n = 13) on day 6 (day 0 = estrus onset). A total of 60 morulae were vitrified (treatment group). After 1 week of storage, the vitrified morulae were warmed. Vitrified-warmed and non-vitrified fresh morulae (control; n = 40) were cultured for 24 h to assess embryo survival by stereomicroscopy after. A total of 30 vitrified/warmed embryos that were deemed viable and 30 fresh control embryos (three pools of 10 for each experimental group) were selected for microarray analysis. Gene expression was assessed with a GeneChip® Porcine Genome Array (Affymetrix). An ANOVA analysis p-unadjusted <0.05 and a fold change cut-off of ±1.5 were set to identify differentially expressed genes (DEGs). Data analysis and biological interpretation were performed using the Partek Genomic Suite 7.0 software. The survival rate of morulae after vitrification and warming (92.0 ± 8.3%) was similar to that of the control (100%). A total of 233 DEGs were identified in vitrified morulae (38 upregulated and 195 downregulated), compared to the control group. Nine pathways were significantly modified. Go-enrichment analysis revealed that DEGs were mainly related to the Biological Process functional group. Up-regulated DEGs were involved in glycosaminoglycan degradation, metabolic pathways and tryptophan metabolism KEGG pathways. The pathways related to the down-regulated DEGs were glycolysis/gluconeogenesis, protein export and fatty acid elongation. The disruption of metabolic pathways in morulae could be related to impaired embryo quality and developmental potential, despite the relatively high survival rates after warming observed in vitro. In conclusion, vitrification altered the gene expression pattern of porcine morulae produced in vivo, generating alterations in the transcriptome that may interfere with subsequent embryo development and pregnancy after embryo transfer.

The effectiveness of prostaglandin nanoparticles in corpus luteum regression

Research examined the formation of prostaglandin nanoparticles and their effect on corpus luteum (CL) regression carried out at IRIAP. The nanoparticles formation was carried out using the ionic gelation method. The nanoparticles have a particle size of 316.80±0.14 nm, polydispersion index of 0,453±0,001, zeta potential of +17,40±0,85 mV with 69,69±8.81% hormone entrapment. The effectiveness of nanoparticle in CL regression was observed (prostaglandin vs prostaglandin nanoparticles) using ultrasound observation, hormone profile and estrus response. Further, the size of the ovulating follicle, the time of ovulation, the size of the CL and the onset of estrus after the administration of the prostaglandins were observed. The observation showed that the intramuscular administration of prostaglandin and prostaglandin nanoparticles did not significantly differ on the onset of estrus, time of ovulation, the ovulating follicle size, size of CL and progesterone concentration. The onset of estrus occurred on 2.50 ± 0.58 and 2.33 ± 0.52 days, the ovulation time after hormone administration was on days 3.50 ± 0.55 and 2.83 ± 0.75 with the ovulation follicle size of 16, 62 ± 0.96 and 17.03 ± 1.13 mm, while the CL measures at H-3 were 13.56 ± 2.28 and 10.45 ± 0.88, the progesterone H-2 concentrations were 0.299 and 0.395, respectively for prostaglandin and prostaglandin nanoparticles. It can be concluded that the formation of nanoparticles did not impair the effectiveness of hormones in CL regression so that it can be used to increase the effectiveness of estrus synchronization

​Induction of Postpartum Oestrus in Lakhimi Cows through Hormonal and Nutritional Interventions

Background: Postpartum anoestrus is the most devastating cause of the dairy farming which causes more economic losses to the farmers. The present study was conducted to record the incidence of postpartum anoestrus and to evolve a suitable therapeutic regime for addressing postpartum anoestrus in Lakhimi cows. Methods: A total of 1000 Lakhimi cows maintained in different villages of Assam were selected and the incidence rate was recorded on the basis of breeding records provided by the farmers, per-rectal examination and ultrasonography screening of genital organ. To study the effect of hormonal and nutritional interventions in post partum anoestrus cows, the cows were divided randomly into seven groups comprising twelve animals in each group. The different treatment regimes were Hydroxyprogesterone caproate + eCG, Clomiphene citrate alone, Clomiphene citrate + Mineral mixture, GnRH analogue alone, GnRH analogue + Mineral mixture, Mineral mixture alone and control. The response to different treatment regimes was based on oestrus response, mean interval from the end of treatment to onset of oestrus and conception rate. Result: The incidence of postpartum anoestrus was found to be 20.60%. Clomiphene citrate + Mineral mixture administration regime brought about the highest oestrus induction response (100.00%) and conception rate (66.67%).

Estrus detection in tie-stall housed cows through supervised machine learning using a multimodal tail-attached device

In this study, the authors developed a novel multimodal tail-attached device with a thermistor and 3-axis accelerometer that can monitor physiological (body surface temperature (ST)) and behavioral (activity intensity, standing time, and posture changes: standing to lying or vice versa) parameters in cattle. The applicability of the device for estrus detection was also evaluated based on supervised machine learning using the data obtained by continuous measurements of these parameters in tie-stalled cows. Data were collected at 3-min intervals for a total of 25 estrous cycles of 13 cows from Day 10 of the cycle (Day 0 = ovulation day) until Day 11 of the subsequent cycle. Estrus was confirmed based on the standing-to-be-mounted behavior by testing with herd mates at 6-h intervals. After the end of estrus, transrectal ultrasonography was performed every 2 h to confirm ovulation time. The maximum ST, average activity, standing time, and number of posture changes were calculated per hour. For analysis, the calculated data were expressed as residual values and ratios, namely, residual ST (rST = actual ST − mean ST for the same time in the previous three days) and ratios of activity intensity, standing time, and posture change (each ratio = total value during the last 24 h / total value during the last 24–48 h). The mean rST and ratios of activity intensity and standing time gradually increased to approximately 60 h before ovulation, with a peak at estrus (approximately 24 h before ovulation). The posture change ratio started to decrease from approximately 48 h before ovulation and reached its lowest level at the onset of estrus (approximately 30 h before ovulation). A total of 20 features (5 physiological and 15 behavioral features) that could to follow-up the estrus-associated changes were extracted and used for developing nine estrus detection models based on 3 feature sets (physiological features alone, behavioral features alone, and a combination of these features) and 3 machine learning algorithms (decision tree, artificial neural network, and support vector machine (SVM)). Cross-validation showed that the sensitivity of the models tended to be high when using a combination of physiological and behavioral features, regardless of the algorithms, although there was no statistical difference in precision among the nine models. The best model generated by the SVM could detect the estrus with a sensitivity of 92.0% and precision of 54.8%, indicating that the newly developed multimodal tail-attached device has the potential for estrous detection in tie-stalled cows.

Administration of royal jelly in estrus synchronization protocols for wool and hair sheep

Objective: To assess the most relevant results on the usage of royal jelly in reproductive protocols of wool and hair sheep. Design/methodology/approach: A review of studies referenced and published in scientific databases regard the livestock sector. Results: In ewes, administration of “royal jelly” in addition to reproductive management protocols improves the response to estrus synchronization, time of onset and duration of estrus, number of large follicles, ovulatory rate and gestation rate. Study limitations/implications: Royal jelly is a substance with beneficial effects on reproductive variables in ewes; however, the cost may be a limitation for its incorporation in synchronization protocols. Additionally, it is necessary to clarify the active metabolites that exert the action and the most effective route of administration. Findings/conclusions: Royal jelly can be an alternative incorporated to estrus synchronization programs in ewes to substitute some hormones without decreasing reproductive variables.

250 Effect of Pre- and Post-ai Nutrition on Ovarian Dynamics, Steroidogenesis, and Expression of Estrus in Beef Heifers

Abstract The objective of this study was to evaluate nutrition before and after artificial insemination (AI) on follicular dynamics, expression of estrus, and steroidogenesis. Seventy-nine beef heifers were randomly assigned to one of two dietary treatments (High;155% and Low;86% of maintenance energy) 30d prior to AI. Estrus was synchronized (PG 6-d CIDR protocol) and heifers received AI (d0) 8 to 12h following onset of estrus. On d0, heifers were randomly reassigned diets generating four Pre-x-Post-AI nutritional treatments; High-High (HH, n = 20), High-Low (HL, n = 20), Low-High (LH, n = 19), and Low-Low (LL, n = 20). Heifers remained on new diet treatments until embryo collection (flush; d7-8). Blood samples were collected daily from d-3 to d0, and on d1, 3, 5, 7 and 8 for plasma concentrations of estradiol (E2) and progesterone (P4). Dominant follicle diameter was evaluated on d-3 and d0, and CL diameter was recorded at flush. Statistical analyses were completed in SAS using the MIXED (body weight, E2, P4), GLIMMIX (expression of estrus), and GLM (ovarian parameters, interval to estrus) procedures. There were Pre-AI (P &amp;lt; 0.0001) and Post-AI by time (P &amp;lt; 0.0001) interactions on body weight; heifers in high and low treatments gained and lost weight, respectively, during both periods. Estradiol concentrations increased (P &amp;lt; 0.0001) from d-3 (2.18±0.15pg/mL) to d0 (6.05±0.04pg/mL). Pre-AI diet increased the proportion of heifers in estrus (80±6.3% vs. 59±7.9%; P = 0.05), and dominant follicle size (11.7±1.42mm vs. 10.68±1.33mm; P = 0.0016) in High vs. Low, respectively. Additionally, High Pre-AI heifers had greater P4 after AI compared to Low Pre-AI heifers (4.85±0.37ng/mL vs. 3.53±0.38ng/mL; P = 0.015). Post-AI treatment did not influence concentrations of P4 (P = 0.88). There was no effect of Pre, Post or Pre-x-Post-AI treatment on initial follicle size, follicle growth rate, E2 concentrations, interval to estrus, or CL size at flush (P &amp;gt; 0.10). In conclusion, nutrient restriction before AI negatively impacted ovarian function, steroidogenesis, and expression of estru.

Altrenogest treatment during the last week of lactation on ovarian traits and subsequent reproductive performance of primiparous and multiparous sows

High-quality follicles result in larger corpora lutea (CL), producing more progesterone, and having a fundamental role in pregnancy maintenance. For some sows, follicular growth takes place during lactation, and follicle selection occurs under a catabolic environment. As altrenogest inhibits follicular development, this study aimed to evaluate follicular growth, CL size, estrus expression, and subsequent reproductive performance of sows treated with altrenogest during the last seven days of a three-week lactation. A total of 81 primiparous and 319 multiparous sows were allocated to two treatments: CONT (control group) and ALT (20 mg of altrenogest/day during the last seven days of lactation). Subsamples of 20 primiparous sows and 97 multiparous were randomly selected to evaluate follicular growth and 26 multiparous sows for serum progesterone analysis at day 21 of gestation. On day 21 of pregnancy, CL measurement was performed by ultrasound. Once in estrus, sows were post-cervically inseminated with pooled semen doses with 1.5 × 109 sperm cells at estrus onset and every 24 h during the standing reflex period. Sows not showing estrus until 10 days after weaning were considered in anestrus. The variables weaning-to-estrus interval, CL size, litter size in the subsequent cycle, and piglet birth weight were evaluated using the GLIMMIX procedure and compared using the Tukey–Kramer test. Anestrus, pregnancy, farrowing, and adjusted farrowing rate were evaluated as binary responses using logistic regression. Follicular size was analyzed as a repeated measure during treatment and after weaning. Treatment was considered as a fixed effect. During the treatment period, follicular size was smaller in ALT sows than CONT sows (3.29 vs. 3.52 mm; P < 0.001). However, after treatment, ALT sows showed a larger follicular size than CONT sows (5.30 vs. 5.03 mm; P ≤ 0.01). There were less ALT sows showing estrus than CONT sows on days three (1.03 vs. 4.57%) and four (55.38 vs. 68.02%) after weaning (P ≤ 0.05), respectively. At 21 days after insemination, ALT sows showed larger CL size and lower CL size variation (P < 0.01) than CONT sows. Anestrus rate, pregnancy rate, farrowing rate, adjusted farrowing rate, litter size in the subsequent cycle, piglet birth weight, litter birth weight, and birth weight variation did not differ between treatments (P ≥ 0.14). In conclusion, altrenogest treatment during the last week of lactation concentrated estrus expression on day five after weaning, larger follicle and CL sizes; however, with no improvement in reproductive performance.

Suckling and Excess Fat in the Postpartum Reproductive Activity of Hair Sheep

Objective: To evaluate the effect of excess fat and suckling control on postpartum reproductive activity of hair ewes. Design/Methodology/Approach: Eighty-one (81) hair ewes with average weight of 58±8 kg were used, which on postpartum day 7 were assigned to one of four treatments under a completely randomized design with 2×2 factorial arrangement. Factor A is the type of suckling [continuous suckling (CS) and suckling control (SC)] and factor B, excess fat (with or without). In CS, ewes remained with their offspring 24 hours a day (n=16). In continuous suckling plus fat (CSF), ewes remained with the offspring all day plus the addition of 8% in dietary fat (n=24). In SC, it was 30 min of suckling only twice per day (n=14). In suckling control plus fat (SCF), controlled suckling lasted 30 min, twice a day plus 8% fat (n=25). Results: The response to the treatments was similar (p &gt; 0.05) in onset of estrus, return rate, gestation, prolificacy and fertilization; for the lambing rate variable, there were differences (p ≤ 0.05), the SCF treatment was higher (68%) compared to CS (50%) and CSF (50%), but equal (p &lt; 0.05) to SC (57.1%). Implications: In this experiment, it was observed that the SCF treatment presented a better response, implying that controlling suckling and providing excess fat helps to restore ovarian activity sooner after lambing. Conclusions: Suckling control plus inclusion of dietary excess fat in ovulation induction protocols during early postpartum (around day 25 postpartum) can be included in routine reproductive management of flocks, improving the reproductive efficiency of hair sheep.

Efficiency of prostaglandins and progestogens in synchronization and stimulation of estrus in recipient goats

Intravaginal implants containing 40 mg of progesterone for synchronization and stimulation schemes of estrus in recipient goats, with a period of exposure to the animal’s body of 6 and 12 days in combination with fertadine and folligon at different reproduction periods during the year, allows to reduce time of estrus onset in animals up to 30 hours or 2.5 times compared to goats treated only with prostaglandins, while inducing estrus in 100.0% of goats with embryo engraftment in recipients of 56.7% on the 40th day of diagnosis and 50.0% upon animals birth with litter yield of 146.7%.

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 18hr after the onset of oestrus) and conventional semen (CS; at 12hr 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 72hr 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 72hr after PGF2α received 100μg of GnRH and CS insemination concomitantly. Two weeks later, cows were penned with natural service sires (bull:cow ratio 1:25) for 45days. Pregnancy was diagnosed 30days 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 18hr after onset of oestrus was 97% of CS insemination at 12hr 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%.

Effect of exogenous administration of oxytocin on postpartum follicular dynamics, oestrous rate and ovulation in Nili-Ravi buffaloes.

Based on different surveys, dairy farmers are concerned about extensive use of exogenous oxytocin in buffaloes, which is being held responsible for reproductive problems including irregular oestrous cycle and delayed ovulation. For these concerns, effects of oxytocin injection on postpartum follicular dynamics, postpartum oestrous interval (PEI), oestrous length, the interval from onset of estrus to ovulation and blood progesterone (P4) were studied in Nili-Ravi buffaloes. For this purpose, 23 animals within 1week after calving were randomly divided into three groups: without oxytocin (CON; n=7), 10 i.u. oxytocin (LOW; n=8), 30 i.u. oxytocin - (HIGH; n=8) and used to record the PEI for the study period of 154days. At subsequent estrus, three buffaloes from each group (not served) were selected randomly to monitor two cycles for 6weeks. Transrectal ultrasonography was performed to evaluate follicular and corpus luteum (CL) development, and blood sampling was done for progesterone (P4) analysis. These results revealed that postpartum oestrous interval (PEI) decreased significantly in oxytocin-treated groups. The number of small, medium and total follicles on the left ovary was significantly higher in the HIGH group. However, an overall number of small and total follicles on both right and left ovaries was significantly higher in CON and HIGH groups. On the other hand, there was no difference in the number of follicles on the right ovary among all treatment groups. The same was true for the size of pre-ovulatory follicles, CL, P4 concentrations and oestrous cycle length. The intervals from onset of estrus to ovulation and from standing estrus to ovulation were increased considerably in the HIGH group. It is concluded that exogenous oxytocin administration resulted in the shortening of PEI but triggered a delay in ovulation. Moreover, a higher dose of oxytocin could stimulate the growth of small, medium, and total follicles in postpartum Nili-Ravi buffaloes.

Evaluation of the molecular response of corpora lutea to manganese-amino acid complex supplementation in gilts.

Porcine pregnancy establishment and maintenance are dependent on the formation of functional corpora lutea (CL). Manganese (Mn) is critical for CL function as it is a cofactor for Mn superoxide dismutase and enzymes involved in cholesterol synthesis. Previously, we have shown that luteal Mn content increased and luteal progesterone (P4) concentration decreased in the CL of gilts fed diets supplemented with an Mn–amino acid complex (Availa-Mn; Zinpro Corporation) compared with controls fed Mn sulfate. Importantly, serum P4 increased from 0 (estrus onset) to 12 d post estrus (dpe), as expected, but P4 abundance in circulation was not affected by dietary Mn source (P = 0.15). We hypothesized that a more bioavailable Mn source (which results in increased luteal Mn content) would alter the luteal proteome and abundance of mRNA associated with steroid biogenesis during the mid-luteal phase of the estrous cycle. Postpubertal gilts (n = 32) were assigned to one of the four gestation diets. The control diet (CON) contained 20 ppm of supplemental Mn in the form of Mn sulfate. Three additional diets included 20 (TRT1), 40 (TRT2), or 60 (TRT3) ppm of supplemental Mn in the form of a Mn–amino acid complex instead of Mn sulfate. Dietary treatment began at estrus synchronization (approximately 20 d before estrus) and continued through 12 dpe when gilts were euthanized and tissues were collected. Protein and total RNA extracts from the CL were used for proteomic analysis via label-free liquid chromatography with tandem mass spectrometry to assess global protein abundance and quantitative real-time polymerase chain reaction (qRT-PCR) to assess specific mRNA abundance, respectively. Compared with CON, 188, 382, and 401 proteins were differentially abundant (P < 0.10) in TRT1, TRT2, and TRT3, respectively. Gene Ontology enrichment software revealed that proteins involved in P4 signaling and cholesterol synthesis were downregulated in CL of gilts fed Mn–amino acid complex compared with controls. Quantitative RT-PCR showed that relative transcript abundance of genes encoding steroidogenic enzymes (CYP11A1 and StAR) in CL tissue was decreased in gilts from TRT2 compared with CON (P = 0.02), but TRT1 and TRT3 were not affected (P ≥ 0.30). Collectively, these data support our hypothesis that a more bioavailable dietary Mn source may influence luteal function by altering the abundance of protein and mRNA involved in steroidogenesis.

Angka kebuntingan sapi perah dengan korpus luteum persisten setelah pemberian kombinasi prostaglandin F2α dan gonadotropin

This case study aims to determine the effect of a combination of prostaglandin F2α (PGF2α) with Gonadotropin (PG-600), and human chorionic gonadotropin (hCG) on the estrus and pregnancy rates in Holstein Friesian (HF) cows with persistent corpus luteum (PCL). A total of 15 Holstein Friesian (HF) dairy cows aged 3-5 years with body condition score (BCS) 5-7 (scale 1-9) diagnosed with PCL, were injected with 7.5 mg PGF2α intra-vulvar submucosa. Cows were then divided into three treatment groups. Group P0 was not given the combination treatment, while P1 group was injected with a combination of 300 IU PG-600 and 150 IU hCG, meanwhile P2 group was was injected with a combination of 300 IU PG-600 and 300 IU hCG intra-muscularly. The PGF2α and PG-600 injections were carried out on the same day PCL was diagnosed. Meanwhile, the injection of hCG was carried out at the same time as the AI. The Pregnancy examination was performed 90 days after AI through rectal palpation. The results showed that all treated cows were estrus observed with the fastest onset of estrus was the P2 group, that was significantly different (p &lt;0.05) compared to the P0 and P1 groups. All treated cows were diagnosed as pregnant. It can be concluded that the administration of PGF2α or its combination with gonadotropins in HF cows with PCL could result in 100% estrus and pregnancy rates.