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The aim of the research was to assess whether there was a link between serum calcium (Ca) after calving and serum progesterone, milk somatic cells count and Ca, and other blood metabolites in Achai and crossbred cows. Based on blood calcium level shortly after calving, thirty cows from both breeds were divided into a moderate group (≤10.0 mg/dl of Ca) and a high group (>10.0 mg/dl of Ca), with samples collected at 0, 7, 14, 21, 28 and 35 days post‐partum, respectively. On day 35 of the post‐partum, crossbred and Achai cows with high blood Ca recorded significantly (p <.01) higher serum progesterone, glucose, triglyceride and milk Ca compared with moderate blood Ca group; however, serum cholesterol was significantly (p <.01) higher in both breeds under high blood Ca. Incidence of subclinical mastitis was significantly (p <.01) higher in crossbred and Achai cows under high blood Ca. The results showed that blood progesterone (OR=2.095), glucose (OR=1.024), triglyceride (OR=4.571), cholesterol (OR=1.111) and milk Ca (OR=1.141) resulted in a greater concentration in crossbred compared to Achai cows. A significant (p <.01) correlation was found between blood Ca and other blood metabolites (progesterone, glucose, triglyceride and cholesterol) in both breeds. In conclusion, greater serum Ca concentration after calving is associated with greater serum progesterone, glucose, triglyceride and milk Ca in crossbred cows; however, the incidence of subclinical mastitis increased. [ABSTRACT FROM AUTHOR]

Evaluating fertility traits based on endocrine progesterone profiles is becoming a promising option to improve dairy cow fertility. Several studies have been conducted on endocrine fertility traits, mainly in the Holstein breed. In this study, focusing also on the Swedish Red (SR) breed, genetic parameters were estimated for classical and endocrine fertility traits, the latter based on in-line milk progesterone records obtained for 14 Swedish herds using DeLaval Herd Navigator (DeLaval International, Tumba, Sweden). A total of 210,403 observations from 3,437 lactations of 1,107 SR and 1,538 Holstein cows were used. Mixed linear animal models were used for estimation of genetic parameters. Least squares means analysis showed that Holstein cows had a 2.5-d-shorter interval from calving to commencement of luteal activity (C-LA) and longer length of first inter-ovulatory interval (IOI) than SR cows. The highest mean interval for C-LA, IOI, and first luteal phase length (LPL) was observed in the fourth parity. The incidence of short (<18 d), normal, (18–24 d), and long (>24 d) IOI was 29.3, 40.7, and 30%, respectively. Genetic analysis indicated moderate heritability (h 2) for C-LA (h 2 = 0.24), luteal activity during the first 60 d in milk (LA60, h 2 = 0.15), proportion of samples with luteal activity (PLA, h 2 = 0.13), and calving to first heat (CFH, h 2 = 0.18), and low heritability estimates for LPL (h 2 = 0.08) and IOI (h 2 = 0.03) in the combined data set for both breeds. Similar heritability estimates were obtained for each breed separately except for IOI and LPL in SR cows, for which heritability was estimated to be zero. Swedish Red cows had 0.01 to 0.06 higher heritability estimates for C-LA, LA60, and PLA than did Holstein cows. Calving interval had moderate heritability among the classical traits for Holstein and the combined data set, but h 2 was zero for SR. Commencement of luteal activity had a strong genetic correlation with LA60 (mean ± SE; −0.88 ± 0.06), PLA (−0.72 ± 0.11), and CFH (0.90 ± 0.04). Similarly, CFH had a strong genetic correlation with IOI (0.98 ± 0.20). Number of inseminations per series showed a weak genetic correlation with all endocrine traits except IOI. Overall, endocrine traits had higher heritability estimates than classical traits in both breeds, and may have a better potential to explain the actual reproductive status of dairy cows than classical traits. This might favor inclusion of some endocrine fertility traits—especially those related to commencement of luteal activity—as selection criteria and breeding goal traits if recording becomes more common in herds. Further studies on genetic and genomic evaluations for endocrine fertility traits may help to provide firm conclusions. A prerequisite is that the data from automatic devices be made available to recording and breeding organizations in the future and included in a central database. [ABSTRACT FROM AUTHOR]

The objective was to determine if the introduction of androgenized steers or females in oestrus has luteolytic effects during the advanced luteal phase (Day 12–13 of the cycle, Day of ovulation = Day 0) in heifers by analysing the changes in corpus luteum (CL) size and perfused area together with progesterone (P4) secretion. Experiment 1 (EXP1) was carried out in May (autumn) with 12 Angus and Angus X Hereford heifers and experiment 2 (EXP2) in September (spring) with 20 heifers of the same breed. Procedures for both experiments were the same. Firstly, oestrus was synchronized in heifers, then, transrectal colour doppler ultrasonography was performed daily from Day 10 to Day 12 of the cycle in all animals. On Day 12 in the afternoon, animals were allocated to two experimental groups (control and biostimulated) and maintained separated (minimum distance: 1000 m) until the end of each experiment. In EXP1, two androgenized steers were introduced into the biostimulated group (BAS) and compared with unstimulated control group (CON1). In EXP2, 20 animals were separated into control group (CON2) and biostimulated group (BHE), in which 4 oestrous heifers were introduced on Day 12 in the afternoon, and 4 more on day 13. The oestrous heifers were injected with 2 mg i.m. of oestradiol benzoate every 12 h until the end of the experiment to maintain the receptiveness. In both experiments, from Day 13 until the day on which detectable luteal blood flow (irrigation) disappeared, colour doppler ultrasonography was performed every 12 h in both groups. Blood samples were collected from all heifers every 12 h from Day 10 to the day in which irrigation disappeared. In EXP1 there was no effect of treatment on CL volume. The BAS had less CL's perfused area than controls 0.09 ± 0.02 cm2 vs 0.16 ± 0.02 cm2, respectively (p = 0.015), less percentage of perfused area (2.4 ± 0.4% vs 4.2 ± 0.4%; p = 0,011), and lower progesterone (P4) concentration than CON1 (2.7 ± 1.0 ng/mL vs 5.8 ± 0.9 ng/mL respectively; p = 0.046). On Day 14.5 of the cycle, the BAS tended to have a lower concentration of P4 than the CON1 (p = 0.06) and on Days 15.5, 16, 16.5, 17, 17.5, 19.5 the P4 concentration was lower in BAS than in CON1 (p < 0.05). In EXP2 there were no treatment effects in any of the studied variables. Overall, it was concluded that the introduction of androgenized steers during heifers' advanced luteal phase of heifers advanced the luteolytic process. However, the introduction of oestrous heifers had no effect on luteal activity. • Introduction of androgenized steers during late luteal phase triggered luteolysis. • Corpus luteum of biostimulated heifers regressed earlier. • Blood perfusion of those corpus luteum disappeared earlier. • The introduction of oestrous heifers did not modify the luteal activity. [ABSTRACT FROM AUTHOR]

The main objective of the current study was to measure the effect of incomplete milking on luteal activity and on pregnancy hazard. We also aimed to study the effect of early-lactation hyperketonemia (i.e., β-hydroxybutyrate blood concentration ≥1.4 mmol/L during the first 3 wk in milk) on those reproductive outcomes. Multiparous Holstein cows (n = 853) from 13 commercial herds were enrolled in a randomized controlled trial. Cows were assigned to a control or a treatment group, incompletely milked (10-14 L of milk collected/d) from 1 to 5 DIM. Blood samples were collected once a week during weeks in milk 1 to 3 for β-hydroxybutyrate blood concentration, and a threshold of 1.4 mmol/L was used to define hyperketonemia. During weeks in milk 5 and 7, cows were sampled for progesterone blood concentration, and a threshold of 1 ng/mL was used to define luteal activity. Reproductive information and culling dates were obtained through herd records. Logistic regression models and survival analyses were used to assess the effect of treatment on luteal activity and on pregnancy hazard, respectively. Analogous models were used to investigate the effect of early-lactation hyperketonemia on reproductive outcomes. The odds of luteal activity for incompletely milked cows were 1.1 (95% confidence interval: 0.72-1.7) times those of conventionally milked cows. The effect of treatment on pregnancy hazard varied as a function of time, parity, and start of the breeding period. In second-parity cows that started the breeding period <55 d in milk, the pregnancy hazard (95% confidence interval) in incompletely milked cows was 576.3 (240.0-1,383.7), 36.9 (18.9-72.1), 6.8 (3.3-13.8), 2.5 (1.0-5.9), and 0.13 (0.07-0.26) times that of conventionally milked cows at 1 to 21, 22 to 43, 44 to 65, 66 to 87, and >87 d after the voluntary waiting period, respectively. The treatment did not have an effect on pregnancy hazard in cows in third parity or greater or in those starting the breeding period ≥55 d in milk. Early-lactation hyperketonemia was not associated with any of the reproductive outcomes. In conclusion, the incomplete milking protocol had no effect on luteal activity and had a positive effect on pregnancy hazard in second-parity cows in herds with a short voluntary waiting period (<55 d). We did not observe an effect of early-lactation hyperketonemia on luteal activity or on pregnancy hazard. [ABSTRACT FROM AUTHOR]

This study investigated the relationships of thyroid hormones, serum energy metabolites, reproductive parameters, milk yield and body condition score with the different patterns of postpartum luteal activity in the postpartum period. A total of 75 multiparous healthy (free of detectable reproductive disorders) Holstein dairy cows (mean peak milk yield = 56.5 ± 7.0 kg/day) were used in this study. Transrectal ultrasound scanning and blood sample collection were performed twice weekly. Serum concentrations of progesterone (P4) were measured twice weekly and beta-hydroxybutyrate (BHBA), non-esterified fatty acids, thyroxine (T4), 3,30,5-tri-iodothyronine (T3), free thyroxine (fT4) and free 3,30,5-tri-iodothyronine (fT3) were measured every 2 weeks from the 1st to the 8th week postpartum. On the basis of the serum P4 profile of the cows, 25 (33.4%) had normal luteal activity (NLA), whereas 30 (40%), 10 (13.3%), 6 (8%) and 4 (5.3%) had prolonged luteal phase (PLP), delayed first ovulation (DOV), anovulation (AOV) and short luteal phase, respectively. Serum T4 concentrations in PLP cows were higher than that in NLA cows at the 3rd week postpartum and did not change during the period of study, whereas in the NLA cows the concentrations increased (P < 0.05). Further, the least square (LS) mean of serum fT4 concentrations in the DOV and AOV cows were significantly lower than in the NLA cows during the study period (P < 0.05). In addition, the AOV cows had higher LS mean serum BHBA and T4 concentrations than the NLA cows in early weeks postpartum (P < 0.05). In conclusion, the serum thyroid hormones’ profile differs in high-producing dairy cows showing PLP, AOV and DOV in comparison with the postpartum NLA cows.

The aims of the present study were to initially determine the pattern of serum adiponectin concentrations during a normal estrous cycle in high-producing postpartum dairy cows and then evaluate the relationship between the serum concentrations of adiponectin and insulin with the commencement of postpartum luteal activity and ovarian activities in clinically healthy high-producing Holstein dairy cows. During a normal estrous cycle of cows (n = 6), serum adiponectin concentrations gradually decreased (P < 0.05) after ovulation by Day-17 estrous cycle and then increased before the next ovulation. Cows with higher peak of milk yield had lower serum adiponectin concentrations by week 7 postpartum (P = 0.01). Serum adiponectin and insulin concentrations in cows with different postpartum luteal activity (based on the progesterone profile) were evaluated using the following class of cows: normal (≤45 days, n = 11) and delayed (>45 days, n = 11) commencement of luteal activity (C-LA) and four different profiles of normal luteal activity (NLA, n = 5), prolonged luteal phase (n = 6), delayed first ovulation (n = 6), and anovulation (AOV, n = 5). Serum adiponectin concentrations decreased gradually by week 3 postpartum in NLA and then increased; whereas in AOV and delayed first ovulation, they were decreased after week 3 postpartum (P < 0.05). Moreover, serum adiponectin concentrations in NLA were more than AOV at weeks 5 and 7 postpartum (P = 0.05). The increase in the milk yield from weeks 1 to 7 postpartum in prolonged luteal phase (P = 0.05) and AOV (P = 0.04) cows was more than that of NLA cows. Insulin concentrations were almost maintained at a stable level in NLA cows (P > 0.05), whereas they increased in the other groups (P < 0.05). Moreover, adiponectin concentrations in cows with C-LA greater than 45 days decreased more than those with C-LA 45 days or less after week 3 postpartum (P = 0.002). Serum adiponectin concentrations at week 7 postpartum were lower in delayed C-LA (P = 0.01). Milk yield in cows with C-LA greater than 45 days increased more than cows with C-LA 45 days or less postpartum (P = 0.002). Insulin concentrations increased relatively in parallel from weeks 1 to 7 postpartum in cows either with C-LA greater than 45 or with C-LA 45 days or less. We showed for the first time the profile of serum adiponectin concentrations in a normal estrous cycle of dairy cows, and furthermore, it was found that high-producing dairy cows with higher postpartum serum adiponectin concentrations had NLA and earlier C-LA. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Are there differences in estrogen and progesterone secretion in singleton pregnancies, up to Week 11, between spontaneous pregnancies, after controlled ovarian hyperstimulation and fresh embryo transfer (COH + ET) and after frozen embryo transfer in a spontaneous cycle (FET)? SUMMARY ANSWER Serum progesterone and estradiol (E2) concentrations after COH + ET were higher in early pregnancy, lasting up to Week 7–8, than FET and spontaneous pregnancies, while hormone levels after FET did not differ from spontaneous pregnancies. WHAT IS ALREADY KNOWN The risk of adverse perinatal outcomes after COH + ET seems to be increased when compared with spontaneous pregnancies. One of the reasons suggested for this is related to ovarian hyperstimulation. STUDY DESIGN, SIZE, DURATION This was a prospective cohort study consisting of three different groups of pregnant women which were followed-up weekly until Week 11 of their pregnancies. The spontaneous pregnancy group consisted of 41 women, the COH + ET group consisted of 39 and the FET group consisted of 30 women. PARTICIPANTS/MATERIALS, SETTING, METHODS Women in the control group with spontaneous conception were recruited from local prenatal clinics. Women in the COH + ET and FET groups were recruited from the Reproductive Unit of Oulu University Hospital. At each visit, a three-dimensional ultrasonography was performed to examine the ovarian volumes and vascularization. A blood sample was drawn to analyse progesterone and E2 levels. The pregnancy outcome was included in the analysis. MAIN RESULTS AND THE ROLE OF CHANCE At pregnancy Week 5, the serum progesterone levels were higher after the COH + ET (median 312, inter-quartile range 183–480 nmol/l), when compared with the spontaneous (63, 52–80 nmol/l; P < 0.001) and FET (74, 48–96 nmol/l; P < 0.001) pregnancies. At Week 11, the P (189, 124–260 nmol/l) was still higher in the COH + ET group (FET 101, 78–120 nmol/l, P < 0.001; spontaneous 115, 80–139 nmol/l, P < 0.01) than the other two groups. The E2 levels at Week 5 were also significantly higher after COH + ET (4.1, 2.2–6.6 nmol/l) than in the spontaneous pregnancies (1.1, 0.7–1.6 nmol/l, P < 0.001) or after FET (0.7, 0.6–0.9 nmol/l, P < 0.001). The volume of the ovaries and the intraovarian vasculature in the COH + ET group were significantly higher when compared with the other two groups (P < 0.001). The birthweight was negatively correlated with the serum P (R −0.340, P < 0.01) and E2 (R= −0.275, P < 0.05) in pregnancy Weeks 5–8. In the multivariate analysis evaluating the factors affecting birthweight of the newborn, the significant factors were the length of gestation, maternal height and progesterone or E2 secretion during Weeks 5–8. LIMITATIONS, REASONS FOR CAUTION Because of the low number of patients in this study, larger cohort studies are required to confirm the findings. WIDER IMPLICATIONS OF THE FINDINGS The findings here indicate that COH-induced increased luteal activity should be evaluated by measuring steroid levels or the ovarian size or vascularity, rather than number of oocytes retrieved. If unphysiologically high steroid activity during pregnancy after COH contributes to the risk of adverse perinatal outcomes after fresh embryo transfer, milder stimulation protocols or even freezing of all of the embryos should be considered. STUDY FUNDING/COMPETING INTERESTS This study was supported by a research grant from the Academy of Finland. The authors declare no conflicts of interest. [ABSTRACT FROM PUBLISHER]

Postpartum energy status is critically important to fertility. However, studies dealing with the relationship between both traits are rare and most refer only to the phenotypic level. In this study, random regression models were used to generate cow-specific lactation curves for daily breeding values (BV) of energy balance (EB) to assess the effect of genetic merit for energy status on different traits derived from progesterone profiles and on subsequent reproductive performance of high-producing dairy cows. Individual feed intake, milk yield, and live weight were recorded for lactation d 11 to 180, and EB was estimated on a daily basis. The results provided the basis for the estimation of BV for 824 primiparous Holstein-Friesian cows. For a subset of these cows (n = 334), progesterone profiles for the resumption of ovarian activity were available. Four different traits describing the genetic merit for EB were defined to evaluate their relationship with fertility. Two EB traits referred to the period in which the average daily EB across all cows was negative (d 11 to 55 postpartum), and 2 parameters were designed considering only daily BV for d 11 to 180 in lactation that were negative. We found that cows with a high genetic merit for EB had a significantly earlier resumption of ovarian activity postpartum. Thus, an EB (indicator) trait should be included in future breeding programs to reduce the currently prolonged anovulatory intervals after parturition. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the pattern of luteal activity in Bulgarian Murrah buffaloes during the first 50 postpartum days by blood progesterone analysis and ultrasonographic corpus luteum detection and its effect on reproductive performance of animals. The study was conducted with 15 clinically healthy Bulgarian Murrah buffaloes after normal delivery of a single foetus, reared and fed uniformly in the presence of a breeding bull. Luteal activity was detected through enzymatic immunoassay of blood progesterone concentrations at 3-day intervals between postpartum days 1 and 50, and ultrasonographic detection of corpus luteum in one ovary. Pregnancy status was used as a criterion for reproductive performance evaluation. After birth records exploration and ultrasound pregnancy check on the 11th month after the beginning of the experiment, two groups of buffaloes were formed: group 1 (n=5) consisting of non-pregnant buffaloes and group II (n=10) -- pregnant animals. Mean blood progesterone concentrations and the cumulative percentage of animals with corpus luteum different than the gestational one, in both groups were determined. According to the results of the study, pregnant buffaloes showed basal blood progesterone levels by the 7th postpartum day and exhibited high luteal activity between postpartum days 19-34, characterised by ultrasonographic detection of a corpus luteum different from the gestational one and blood progesterone concentrations > 0.5 ng/ml after day 34 postpartum. Buffaloes with blood progesterone concentrations < 0.25 ng/ml until the 50th postpartum day and inadequate functional activity of the corpus luteum could remain non-pregnant for a long time after parturition. In conclusion, the pattern of luteal activity in Bulgarian Murrah buffaloes during the first 50 postpartum days had an effect on their reproductive status. The received data could be used for improvement of the protocols for oestrus synchronization and postpartum anoestrus reduction. [ABSTRACT FROM AUTHOR]

Abstract: The aim of the present study was to determine whether a treatment of 3 mo of artificial long days and daily contact with bucks can stimulate reproductive activity during the normal seasonal anoestrous in female goats, and whether such treatment modifies the onset of the normal breeding season. Thirty-nine adult, open does were assigned to two treatments of similar mean body weight (BW) and body condition score (BCS). One treatment (LD; n =18) was housed in a light-proof building and exposed to long days (16h of light/d) from 17 November to 5 February, and then exposed to the natural photoperiod in an open shed. The remaining females were housed in an open shed under natural photoperiod conditions throughout the experiment (control [C]; n =21). Plasma samples for progesterone, BW and BCS were recorded every wk. Oestrous activity was checked daily using aproned bucks. Bucks were housed close to females in a separate barn from the onset of the experiment. Ovulation rate was determined by laparoscopy 7 d after positive identification of oestrus. The interaction of treatment by time for temporal concentrations patterns of progesterone concentrations indicated that luteal activity in LD does were greater (P <0.001) than those of C does during the natural seasonal anoestrous season. None of the C does exhibited oestrous or luteal activity during the non-breeding season; whereas, 72% of LD does exhibited luteal activity only 33% of them showed oestrous activity and during this season (P <0.01). Differences in resumption of the oestrous or luteal activity were not observed (P >0.05) in the subsequent breeding season between treatments. In conclusion, 3 mo of exposing does to long days and daily contact with bucks during the breeding season appears to stimulate reproductive processes that normal would not occur during the anoestrous season. However, this treatment does not induce oestrus is adequate numbers of does to be of practical value. Finally, this treatment does not modify the onset of the subsequent natural breeding season. [Copyright &y& Elsevier]

The article discusses a study which determined the effect of GnRH (buserelin)-induced luteinizing hormone (LH) release in the hypophyseal response of dairy buffaloes during early postpartum period. The results reveal that hypophyseal responsiveness to GnRH- induced LH release and reproduction in early postpartum period is suppressed in buffaloes with high luteal activity as compared to buffaloes with reduced luteal activity. The methods used in preparation, testing, and data analysis are also discussed.

Relationships among commencement of luteal activity (C-LA), milk yield, and energy balance (EB) were investigated in 3 selection lines of Norwegian Red cows at the Norwegian University of Life Sciences from 1994 through 2001. The cows were selected for low genetic merit for milk yield (LMP), high genetic merit for milk yield (HMP), and a combination of high indices for milk yield and fertility (HI). Breeding values for fertility were based on 56-d nonreturn rate. The material included 268 lactations from 147 cows. Milk samples for progesterone analysis were drawn 3 times weekly from 1994 through 1998, and 2 times weekly from 1999 to 2001. Commencement of luteal activity was defined as the first 2 consecutive measurements of progesterone concentration >3 ng/mL not earlier than 10 d after calving. Selection line was significantly related to C-LA, so that the least squares mean days from calving to C-LA were 22.5, 30.4, and 27.2 d for LMP, HMP, and HI cows, respectively. The HMP cows produced more milk than the LMP cows. The average milk yield in the sixth week of lactation was 24.0, 27.1, and 25.3 kg for LMP, HMP, and HI cows, respectively. The interval to C-LA decreased for the HMP and HI cows after phenotypic adjustment for EB in the model. Least squares means for the interval to C-LA were 23.2, 29.7, and 25.6 d for the LMP, HMP, and HI cows, respectively, in a model that included parity, selection lines, and EB as covariates. Cumulated EB during the first 4 wk of lactation, which itself differed between selection lines, did not fully account for differences in interval to C-LA between selection lines. Thus, the results of the present investigation indicate that selection for milk yield negatively affects C-LA over and above the effects caused by concurrent changes in EB. The increase in days to C-LA caused by selection for high yields can be reduced if selection for milk yield is combined with fertility in the breeding program. [ABSTRACT FROM AUTHOR]

The objective of this study was to estimate genetic parameters for measures of luteal activity during the first 60 d postpartum. Analyses were made with different sampling intervals to investigate the possibility of combining progesterone measurement with routinely performed milk recording. Progesterone level in milk as an indicator of female fertility when selecting sires in a progeny-testing scheme was also examined. Data were collected from 1996 to 1999, and comprised 1,212 lactations from 1,080 British Holstein-Friesian cows at 8 commercial dairy farms in the United Kingdom. Milk samples for progesterone analysis were collected thrice weekly. Mixed linear animal models were used to analyze the data. Heritability for the percentage of samples with luteal activity during the first 60 d postpartum (PLA) was 0.30 and decreased with more infrequent sampling to 0.25, 0.20, and 0.14 for weekly, twice- monthly, and monthly sampling, respectively. Measures of PLA had a high negative genetic correlation with prolonged anovulation (-0.53 for monthly sampling, < -0.87 otherwise) and a moderate positive genetic correlation with persistent corpus luteum in the first estrus cycle (>0.65 if at least twice-monthly sampling). Genetic correlations with interval from calving to commencement of luteal activity were close to -1 for all PLA measurements and the selection index calculations showed that monthly progesterone sampling could be used with high accuracy (0.80 with 50 daughters per bull) to predict breeding values for commencement of luteal activity. Progesterone analysis at the time of regular milk recording could thereby be used to select for an early interval from calving to commencement of luteal activity and, at the same time, a decreased frequency of prolonged anovulation during the postpartum period. [ABSTRACT FROM AUTHOR]

Abstract: We related variation in 4 sex steroid genes to 3 phenotypic indicators of ovarian aging, including no evidence of luteal activity as a marker of anovulatory cycles, shorter or longer menstrual cycle lengths, and the profiles of metabolites of estrogens, progesterone, follicle-stimulating hormone, and luteinizing hormone measured in urine samples collected daily across a menstrual cycle in women aged 43 to 53 years. The study sample included 485 menstruating women without hormone therapy who had collected daily urine hormone samples across 1 menstrual cycle or 50 days, whichever occurred first. There were 14 single nucleotide polymorphisms from 4 genes, including estrogen receptor–α (ESR1), estrogen receptor–β, aromatase, and 17β hydroxysteroid dehydrogenase type 1, related to ovarian aging phenotypes that include the presence or absence of luteal activity, menstrual cycle lengths < or > 24 to 31 days, and profiles of urinary hormone metabolites. Women with the TT genotype of ESR1 rs3798577 have evidence of advanced ovarian aging compared with women with the CT or CC genotypes, after adjustment for race/ethnicity, chronologic age, and race/ethnicity-specific body mass index. Further, women with the TC and CC genotypes of ESR1 rs2234693 may have a greater likelihood of more advanced ovarian aging than do women with the TT genotype, adjusting for covariates. Using a candidate gene approach, 2 ESR1 polymorphisms are related to 3 phenotypic markers of ovarian aging, suggesting a possible role for the ESR1 gene in the timing of the menopausal transition. [Copyright &y& Elsevier]

Abstract: Objectives: This trial tested the hypothesis that menstrually signaled use of contraceptive vaginal rings (“rings”) releasing low-dose combinations of Nestorone (NES) and ethinyl estradiol (EE) would reliably suppress luteal activity and ovulation, and prevent unintended pregnancy, while controlling the incidence of menstrual bleeding episodes and bleeding days. Methods: Nestorone/ethinyl estradiol rings releasing 50/10, 50/20 and 150/15 μg/day were studied through 6 months. A ring was to be used continuously, until its removal was signaled by menstrual bleeding. Reinsertion was required 96 h after removal. Serum for NES, EE and progesterone were collected and assayed, and vaginal ultrasound scans were performed in three 5-week periods to examine luteal activity, follicular growth, ovulation and their correlates. In 10 subjects using the 150/15 ring, six samples were drawn in the 24-h period after ring removal to examine serum levels of NES and EE. Results: One hundred sixty subjects at three doses provided blood samples. Median serum concentrations of NES and EE demonstrated dose ratios slightly below the nominal dose ratios expected. Serum NES concentrations declined 19–22% from weeks 3 to 25. Changes in EE levels depended on dose. Nestorone levels fell 81% by 24 h after ring removal and EE levels fell by 50%. Luteal activity was completely suppressed in 94–95% of cycles and in 90% of subjects. Three pregnancies occurred in subjects participating in this serum sampling study. Conclusion: Satisfactory serum levels of NES and EE, and a high level of ovulation suppression were achieved. Irregular ring use, however, permitted pregnancies to occur. [Copyright &y& Elsevier]

Abstract: In a multicenter 1-year trial of contraceptive vaginal rings (rings) involving 150 women, three dose combinations of the progestin Nestorone® (NES) and ethinylestradiol (EE) were compared with respect to effectiveness, safety and acceptability. Mean in vitro drug release rates for the three doses were 150 and 15, 150 and 20 and 200 and 15 μg/day of NES and EE, respectively. Each ring remained in situ for 21 days, removed for 7 days and then reinserted for a total of 13 cycles of use. We studied ring performance with respect to pregnancy and other termination events, adverse events, the extent of ovulation inhibition, serum drug levels and bleeding control. We also assessed the rings'' effects on the vagina using a standardized colposcopy procedure. Seventy-two percent of the women completed the 1-year (≥350 days) study. In studied cycles, luteal activity (progesterone ≥10 nmol/L) was noted in 17%, 7% and 12% of subjects with monitored cycles at the 150/15, 150/20 and 200/15 doses, respectively (p=.34). Two pregnancies occurred, both in subjects using the 200/15 μg/day ring. Breakthrough bleeding during ring use averaged about 2 days/year and breakthrough bleeding and spotting averaged about 7 days/year. In the entire trial, only two women discontinued because of bleeding problems. Medical conditions, chiefly vaginal problems, personal reasons and device loss or repeated expulsion were the principal reasons given for study discontinuation. Vaginal and cervical colposcopy, conducted with standardized techniques and standardized interpretations, revealed no elevated event incidence attributable to ring use. Clinical performance and adverse event profiles indicate that each of these 1-year NES/EE rings, used on a 21-day-in and 7-day-out regimen, provided women effective, acceptable and safe long-acting contraception under their own control. [Copyright &y& Elsevier]

This study was designed to compare two timed insemination protocols, in which progesterone, GnRH and PGF2α were combined, with the Ovsynch protocol in presynchronized, early postpartum dairy cows. Reproductive performance was also evaluated according to whether cows showed high or low plasma progesterone concentration, at the onset of treatment. One hundred and six early postpartum dairy cows were presynchronized with two cloprostenol treatments given 14 days apart, and then assigned to one of the three treatment groups. Treatments for the synchronization of estrus in all three groups started 7 days after the second cloprostenol injection, which was considered Day 0 of the actual treatment regime. Cows in the control group (Ovsynch, n=30) were treated with GnRH on Day 0, PGF2α on Day 7, and were given a second dose of GnRH 32 h later. Cows in group PRID (n=45) were fitted with a progesterone releasing intravaginal device (PRID) for 9 days, and were given GnRH at the time of PRID insertion and PGF2α on Day 7. In group PRID/GnRH (n=31), cows received the same treatment as in the PRID group, but were given an additional GnRH injection 36 h after PRID removal. Cows were inseminated 16–20 h after the administration of the second GnRH dose in the Ovsynch group, and 56 h after PRID removal in the PRID and PRID/GnRH groups. Ovulation rate was determined on Day 11 postinsemination by detecting the presence of a corpus luteum in the ovaries. Lactation number, milk production, body condition at the onset of treatment and treatment regime were included as potential factors influencing ovulation and pregnancy after synchronization. Logistic regression analysis for cows with high and low progesterone concentration on treatment Day 0 revealed that none of the factors included in the models, except the interaction between progesterone and treatment regime, influenced the risk of ovulation and pregnancy significantly. In cows with high progesterone concentration at treatment onset, Ovsynch treatment resulted in a significantly improved pregnancy rate over values obtained following PRID or PRID/GnRH treatment. In cows with low progesterone concentration, PRID or PRID/GnRH treatment led to markedly increased ovulation and pregnancy rates with respect to Ovsynch treatment. These findings suggest the importance of establishing ovarian status in early postpartum dairy cows before starting a timed AI protocol, in terms of luteal activity assessed by blood progesterone. [Copyright &y& Elsevier]

The results of several studies have suggested an inhibitory effect of the antiprogestin RU486 on late stages of folliculogenesis and ovulation. To assess the feasibility of using this property to inhibit ovulation without losing cycle control, an intermittent administration of RU486 alternated with medroxyprogesterone acetate (MPA) was tested in a phase I study. RU486 at a dose of 50 mg/day was given on menstrual cycle days 9–11 and 27–29, and 10 mg/day of MPA was given on cycle days 17–26 for three consecutive cycles to six Finnish and five Chilean women. Blood samples were collected two to three times a week for serum progesterone and oestradiol assays in three treatment cycles. One control cycle and one post-treatment recovery cycle were also monitored by serum samplings. Ultrasonography was carried out to measure follicular diameters in the treatment cycles. In 29 of 32 cycles, bleeding commenced within 3 days after the last MPA pill intake. Out of 32 treatment cycles, 20 were without luteal activity (serum progesterone <9 nmol/l). Although 12 treatment cycles showed luteal activity (serum progesterone ≥9 nmol/l), a clear rupture of a pre-ovulatory follicle >15 mm, verified by ultrasonography, was seen in only one treatment cycle. During the treatment cycles with luteal activity (serum progesterone levels ≥9 nmol/1), serum oestradiol concentrations were significantly higher on cycle days 9–18 and significantly lower at the end of the cycle compared with the cycles without luteal activity. The regimen used in this study disturbed folliculogenesis and ovulation (apparently), and was able to provide good cycle control in the majority of the cycles. [ABSTRACT FROM PUBLISHER]

The objective of this study was to ascertain the presence of luteal activity in crossbred cows through Prostaglandin Induced Milk Flow Test (PGIMFT). The test was studied in 40 non-bred lactating cows using natural PGF2α 400, 600 and 0.00 pg/cow i/v in group I (15), II (15) and III (10), respectively on day 4, 7 and 17 of the estrous cycle. The test response was 66.67, 86.67 and 78.57% in group I; 73.33, 100, and 84.6% in group II and 0.0, 0.0 and 0.0% in group III, respectively at day 4, 7 and 17 of the estrous cycle. The time interval for test response between group I (187.43±28.79, 145.5±12.29 and 163.93±19.70 seconds) and group II (160.20±15.29, 137.67±21.09 and 153.3±15.29 seconds) did not differ significantly. Serum progesterone concentration was found to be significantly higher in positive than of negative cases (P<0.05) at all sampling intervals. [ABSTRACT FROM AUTHOR]

The aims of the present study were to evaluate luteal activity in Abadeh ecotype goat during summer and winter and also the effect of a single dose kisspeptin-10 injection on the secretion of luteinizing hormone (LH) in female anestrous goats. In the first study, progesterone (P4) concentration in 10 goats in summer (n = 6) and winter (n = 4) were measured every other day. Moreover, in summer group, a male teaser goat was left in the herd on days of sampling for one hour. Goats with P4 concentration ≥1 ng mL(-1), at least two consecutive measurements, were considered with luteal activity. In the second study, the anestrous phase was confirmed by P4 measurement 20 and 10 days before the kisspeptin injection in five female Abadeh ecotype goats (4 to 5 years old). The goats were given a single IV injection of saline (2 mL) as control group and the same goats (1 hr after the last blood sampling) were given kisspeptin (1 μg kg(-1)) as treatment group. The blood samples were collected at -60, -40, -20 and 0 min (before injection), and 10, 20, 30, 40, 50, 60, 80, 100, 120 and 140 min after the injection and LH concentration were measured. A single IV injection of 1 µg kg(-1) of kisspeptin-10 did not stimulate the release of LH in female anestrous goats. In summer, in the presence of teaser goat, luteal activity was seen in all goats. In the absence of male goat in winter, some goats showed luteal activity and others showed anestrus.