Effects of intravaginal administration of prostaglandin F2α on luteolysis and subsequent estrus in Shiba goats (Capra hircus).

This study examined the effects of intravaginal administration of prostaglandin F2α (PGF2α ) on luteolysis and subsequent estrus in cycling goats. Goats with functional corpus lutea received one of five treatments: 2 mg of PG intramuscularly (IM2 × 1; n = 6), 2 mg of PGF2α intravaginally (IVG2 × 1; n = 7), 4 mg of PGF2α intravaginally (IVG4 × 1; n = 7), and 1 or 2 mg of PGF2α intravaginally 8 h apart (IVG1 × 2 group; n = 6 and IVG2 × 2; n = 8). Blood samples were collected at 24-h intervals from 0 to 7 days after PGF2α administration. Estrus was checked twice daily during the experiment. The proportion of goats with complete luteolysis (reduction of progesterone concentrations to <1 ng/mL until 48 h after treatment) in the IVG2 × 1 group (28.6%) was significantly lower than in the other groups (IM2 × 1; 100%, IVG4 × 1; 57.1%, IVG1 × 2; 87.5%, IVG2 × 2; 100%, respectively). For goats completing luteolysis, there was no significant difference in the onset and duration of estrus among the groups. These results suggest that intravaginal administration of PGF2α can be applied as an alternative to intramuscular administration.

Effect of linearly polarized microwaves on nanomorphology of calcium carbonate mineralization using peptides.

Microwaves are used for diverse applications such as mobile phones, ovens, and therapy devices. However, there are few reports on the effects of microwaves on diseases other than cancer, and on physiological processes. Here, we focused on CaCO3 mineralization as a model of biomineralization and attempted to elucidate the effect of microwaves on CaCO3 mineralization using peptides. We conducted AFM, ζ potential, HPLC, ICP-AES, and relative permittivity measurements. Our findings show that microwaves alter the nanomorphology of the CaCO3 precipitate, from sphere-like particles to string-like structures. Furthermore, microwaves have little effect on the mineralization when the mineralization ability of a peptide is high, but a large effect when the precipitation ability is low. Our findings may be applicable to not only the treatment of teeth and bones but also the development of organic-inorganic nanobiomaterials. This methodology can be expanded to other molecular/atomic reactions under various microwave conditions to alter reaction activity parameters.

Evaluation of prepartum and postpartum stress by measuring hair cortisol concentrations of Holstein dairy cows and their calves and its relationship to calving conditions and health status.

Periparturient stress can have long-term negative effects on both dairy cows and their calves and may contribute to lower productivity. The purpose of this study was to determine how periparturient stress is related to differences in calving difficulty and health status by measuring hair cortisol concentration in periparturient dairy cows and their calves. Calving environment (calving pen, tie stall, and group paddock), calving difficulty, calving progress, health status, and calf weight were recorded, and tail hair from 25 of the cows and their calves was collected at calving and 1 month after calving to measure hair cortisol concentration. There were no significant correlations between hair cortisol concentration and calving environment, calving difficulty, calf weight gain rate. Hair cortisol concentrations at calving were significantly higher in cows with oversized calves or twin births than in cows with normal-sized singleton calves (4.2 ± 2.2 pg/mg vs. 2.1 ± 1.5 pg/mg, P<0.05). Cows with clinical disease within one month of calving had significantly higher levels of hair cortisol one month after calving compared to healthy cows (3.8 ± 1.1 pg/mg vs. 2.3 ± 1.9 pg/mg, P<0.05). Calves with clinical disease within the first month after birth tended to have higher hair cortisol levels at birth than healthy calves (4.7 ± 2.4 pg/mg vs. 3.2 ± 0.9 pg/mg, P<0.1). These results suggest that calving of oversized calves and twin births and suffering clinical diseases can cause more stress for cows during the periparturient period.

Relationship between ovarian ultrasonographic findings on the seventh post-estrus day and plasma progesterone concentration, nutritional metabolic factors, and pregnancy outcome in dairy cows.

To improve the accuracy of ultrasonographic assessment of luteal function, we investigated the relationship between ovarian ultrasonographic findings on Day 7 (Day 1 = ovulation) and plasma progesterone (P4) concentration, nutritional metabolic factors, and pregnancy outcome. A total of 47 spontaneous estrus events were investigated in 38 lactating Holstein cows (artificial insemination, n = 31; embryo transfer, n = 16). Transrectal ultrasonography was performed on Days 0 and 7 to measure the pre-ovulatory follicle area on Day 0 and the luteal tissue area (LTA), luteal blood flow area (LBF), relative LBF (rLBF) (= LBF/LTA), and dominant follicle area (DFA) on Day 7. Blood samples were collected on Day 7 to measure plasma P4, insulin-like growth factor-I (IGF-I), insulin, and metabolites. Plasma P4 concentration was positively correlated with LTA but was not associated with LBF or rLBF. Plasma P4 concentration was positively correlated with blood glucose and IGF-I and negatively correlated with blood urea nitrogen and free fatty acid, and no significant relationship was found between the ultrasonographic findings of the corpus luteum (CL) and these blood metabolites. Pregnant cows had smaller DFA than non-pregnant cows. In conclusion, LTA measurement can help predict plasma P4 concentration, but it was difficult to detect variations in plasma P4 concentration in relation to changes in energy status by evaluating the CL ultrasonographically. A combined assessment of CL and first-wave dominant follicle may be important in evaluating fertility.

Effects of short-term dietary supplementation on the number of ovarian follicles, quantity and quality of oocytes, and in vitro embryo production in Japanese Black cows.

This study aimed to test the hypothesis that short-term supplementation with a high-energy diet promotes embryo production following ovum pick-up (OPU) in Japanese Black cows. After a period of adaptation to the maintenance diet, a 200% maintenance diet was fed to the high-energy diet group (HD group, n = 6) for four weeks, and a maintenance diet was fed to the other group (MD group, n = 6). OPU-in vitro fertilization (IVF) procedures were performed on days 14, 21, and 28; follicles and oocytes were counted and morphologically graded, and cultivable oocytes were cultured for in vitro maturation, fertilization, and culture. The mean plasma insulin concentrations on days 14 and 21 were significantly higher in the HD group than in the MD group (P < 0.05). The number of follicles observed at OPU, recovered oocytes, cultivable (Grades 1 to 4) oocytes, and the rate of degenerated (Grade 6) oocytes in the HD group were significantly higher than those in the MD group (P < 0.05). The proportion of cleaved oocytes was lower in the HD group than in the MD group (P < 0.05); consequently, there was no significant difference in the number of blastocysts obtained between the HD and MD groups. The present findings suggest that high-energy diets can promote follicular growth in parallel with an increase in plasma concentrations of insulin, but have a detrimental effect on the quality of oocytes with the OPU-IVF procedure in Japanese Black cows.

Changes in the C-reactive protein and 13,14-dihydro-15-keto-prostaglandin F2α concentrations of uterine lavage samples after the administration of povidone-iodine in cows.

Changes in the C-reactive protein (CRP) and 13,14-dihydro-15-keto-prostaglandin F2α (PGFM) concentrations of uterine lavage fluid were examined in cows given an intrauterine povidone-iodine (PI) infusion. The mean polymorphonuclear leukocyte (PMN) ratios (the ratio of PMN to total cells) and CRP concentration of uterine lavage fluid on the day after the treatment were significantly (P<0.05) greater in the PI infusion group (PMN: 53.0 ± 32.7%, CRP: 50.2 ± 32.3 ng/mL) than in the non-treatment control group (PMN: 7.9 ± 21.9%, CRP: 17.2 ± 5.9 ng/mL), whereas there was no significant difference in the mean PGFM concentration between the two groups. The present findings suggest that the uterine CRP level is a useful biomarker of local uterine inflammation in cows.

Possible causes and treatment strategies for the estrus and ovulation disorders in dairy cows.

The reproductive performance of dairy cows has declined, along with an increase in their milk yield. First-service conception rates in lactating dairy cows are often lower than 50%. The precise detection of estrus is an important factor in the reproductive management of dairy cows for successful fertilization and pregnancy. However, estrus expression has been decreasing in modern dairy cows, affecting the detection rate of estrus. In addition to estrus, a high incidence of ovulation disorders affects the fertility of dairy cows. To address these problems, it is necessary to understand the changes in the endocrine functions that underlie estrus and ovulation disorders, and to develop effective treatment strategies. Recent studies have revealed that neurokinin B and neurokinin 3 receptor signaling play important roles in the regulation of the secretion of gonadotropin-releasing and luteinizing hormones, suggesting a potential clinical avenue for the stimulation of gonadal function. In this review, I have discussed the problems in estrus and ovulation disorders in modern dairy cows as well as the possible applications of neurokinin 3 receptor agonists in the treatment of these disorders.

Intravaginal administration of estradiol benzoate capsule for estrus synchronization in goats.

Estrus synchronization requires multiple treatments of hormonal drugs, requiring considerable time and cost. The aim of the present study was to develop an estrus synchronization protocol using intravaginal administration of estradiol benzoate (EB) capsules in goats. Two types of capsules were prepared: an EB capsule that melted immediately after administration and a sustained-release (SR) EB capsule that dissolved slowly and reached a peak after 24 h. Goats with functional corpus lutea were intramuscularly treated with prostaglandin F2α (PG). At 24 h after PG administration, goats were administered 1 mg of EB solution intramuscularly (PG + 24IM; n = 6) or 1 mg of EB capsule intravaginally (PG + 24EB; n = 6). The SR EB capsule was administered intravaginally at the time of PG administration (PG + SR; n = 6). The control group (n = 6) received only PG. All groups showed estrus within 72 h after PG administration. The onset of estrus did not differ significantly between the PG + 24IM and PG + SR groups but was earlier than in the control group. Estradiol concentration in the PG + SR group peaked at 11.5 ± 6.1 h after EB and PG administration. Peak estradiol concentrations were not significantly different between the PG + 24IM and PG + SR groups (78.0 ± 25.8 and 64.0 ± 38.1 pg/ml, respectively), and were higher than the PG + 24EB and control groups (27.3 ± 8.8 and 14.6 ± 6.1 pg/ml, respectively). These results suggest that intravaginal administration of an EB capsule with a sustained-drug release base is applicable for estrus synchronization, as an alternative to intramuscular administration.

Heart transplant candidate with medical complexity in the era of prolonged left ventricular assist device support - A case report.

Heart transplantation improves quality of life and survival in patients with advanced heart failure. However, the shortage of available heart donors and technological advances for left ventricular assist devices (LVAD) have led to longer waiting times for transplantation, and long-term use of LVAD may increase the medical complexity of subsequent transplantation. We present the case of a 35-year-old man who underwent heart transplantation after being supported by an LVAD for 1490 days (∼4 years). He was sensitized with kidney dysfunction and recurrent infections, including candidemia, at the time of transplantation. He underwent a successful heart transplantation with pretransplant plasma exchange, intravenous immunoglobulin administration, early initiation of everolimus, and prompt management of infections. .

Intravaginal administration of progesterone using a new technique for sustained drug release in goats.

The objective of the present study was to develop and evaluate a sustained release vaginal progesterone (P4) capsule containing a mixture of mucoadhesive polymer and silicone fluid. Goats were administered a gelatin capsule containing 0.4 g of P4 mixed in silicone fluid and either a hydroxypropylmethylcellulose (HM) or polyaclil starch (PA) base. The mean plasma P4 concentrations at 2 and 12 h after administration were significantly higher in goats treated with PA capsules than in those with HM capsules. The plasma P4 concentrations in goats treated with HM capsules increased and remained above 1.0 ng/ml for 96 h after administration, whereas the plasma P4 concentrations in goats treated with PA capsules remained above 1.0 ng/ml for only 24 h after administration. In the next experiment, an HM capsule was attached to a silicone device and inserted in the vagina for 10 days. The plasma P4 concentration remained similar to that of the natural luteal phase for 9 days. These results suggest that a mixture of mucoadhesive polymer and silicone fluid has the potential to be applied clinically as a sustained release base for estrus synchronization or hormonal therapy.

Quantifying the C-reactive protein concentrations of uterine lavage samples in postpartum dairy cows.

Changes in the C-reactive protein (CRP) concentration, a non-specific diagnostic biomarker, in uterine lavage fluid and associations with cytological findings were examined following parturition in dairy cows. In postpartum Holstein dairy cows (n = 8), uterine lavage was performed at 3 and 6 weeks postpartum, and polymorphonuclear leukocyte (PMN) ratios to total cells (PMN:ALL) and to lymphocytes (PMN:LYM) and CRP concentrations were determined. Blood samples were collected to monitor the metabolic variables, and plasma CRP concentrations were quantified using samples collected at the same time as the uterine lavage occurred. A cytological examination was performed to determine PMN:ALL and PMN:LYM. The values for metabolic variables were within the normal range throughout the postpartum period. There was a correlation between the PMN:ALL and PMN:LYM, and both ratios were less (P < 0.05) at 6 than 3 weeks postpartum. The mean CRP concentration of the uterine lavage fluid was less at 6 (27.7 ± 9.6 ng/ml) than 3 weeks (60.8 ± 28.1 ng/ml) postpartum, whereas mean plasma CRP concentration was greater at 6 (287.4 ± 34.1 ng/ml) than 3 (254.8 ± 29.4 ng/ml) weeks postpartum. The results of the present study indicate the CRP concentration of uterine lavage fluid decreased in parallel with the frequency of PMN during uterine involution, which leads to the suggestion that uterine lavage fluid CRP concentration could be utilized as a local biomarker for evaluating uterine inflammation in cows.

Comparison of antimicrobial susceptibilities of bacterial isolates between cured and uncured cases of bovine mastitis.

To evaluate the effect of antimicrobial susceptibility on outcomes, we compared the minimum inhibitory concentrations (MICs) for Staphylococcus, Streptococcus, and the family Enterobacteriaceae from cured and uncured mastitis cases; milk shipment for uncured cases could not be resumed within 3 weeks after initial clinical examination. A higher MIC50 of ampicillin and a higher MIC90 of cefazolin for Enterobacteriaceae isolates were observed for cured rather than uncured cases with differences in ≥2 tubes. Endotoxins are generally released from Enterobacteriaceae upon antimicrobial treatment; their amounts are presumed to be greater in mastitis cases resulting from ß-lactam antibiotic-susceptible rather than -resistant microbes. For staphylococcal and streptococcal isolates, the MIC50 and MIC90 of ß-lactam antibiotics were similar for cured and uncured cases.

The efficacy of a newly developed neurokinin 3 receptor agonist B21-750 on luteinizing hormone secretion in cycling goats.

This study aimed to investigate the efficacy of a newly developed NK3 receptor agonist (B21-750) on the secretion of luteinizing hormone (LH) in association with ovarian steroid hormones during the follicular phase (FP, n = 5) and luteal phase (LP, n = 5) of Shiba goats. The FP group was treated with both prostaglandin F2α and progesterone-controlled internal drug release (CIDR) inserts for 10 d, and B21-750 (200 nmol) was injected 12 h after removing the CIDR. Meanwhile, the LP group received B21-750 injections on a day during the mid-luteal phase. LH secretion increased at 1 h after B21-750 injection in both groups. The percent changes in the area under the curve of LH was higher during the hour after injection than during the hour before injection in both groups. Thus, this study demonstrated that B21-750 induces rapid LH secretion for a short period during both the follicular and luteal phases.

Hair cortisol concentration in pre- and postpartum dairy cows, and its association with body condition, hock health, and reproductive status.

The objective of this study was to investigate the profiles of hair cortisol concentrations as an index of chronic stress in dairy cows in association with their health, nutrition, and reproductive parameters. For 25 Holstein dairy cows, hair was collected from the tail switch -19.2 ± 11.4, 44.8 ± 11.9, 103.0 ± 9.9, and 168.0 ± 9.7 days postpartum (L0, L1, L2, and L3, respectively). Body condition scores were negatively correlated with hair cortisol concentrations (r = -0.255), and hock health scores were positively correlated with hair cortisol concentrations (r = 0.236, p < 0.05). Hair cortisol concentrations during the postpartum period showed different patterns according to the time of first artificial insemination (AI) and fertility. Cows that were submitted to first AI by 86 days postpartum showed a peak hair cortisol concentration at L1, whereas cows with delayed first AI had a peak at L2. The hair cortisol concentrations of subfertile (≥168 days) cows were significantly higher at L1 and L2 compared with L0, whereas hair cortisol concentrations of fertile cows (<168 days) were not different among the sampling times. These results indicate that cows with health problems appear to experience greater chronic stress, which may impair their reproductive function.

Effect of repeated adrenocorticotropic hormone administration on reproductive function and hair cortisol concentration during the estrous cycle in goats.

Measurement of the cortisol concentration in hair has been used as an index of chronic stress in several species including humans, wildlife and domestic animals. However, how accurately the cortisol concentration in hair reflects the changes in circulating cortisol concentrations has not been well documented. The objective of the present study was to examine the effect of repeated adrenocorticotropic hormone (ACTH) administration on the reproductive function during the estrous cycle and hair cortisol concentrations in goats. In experiment 1, goats were administered ACTH (0.625 IU/10 kg of body weight, n = 6) or saline (n = 6) intramuscularly once a day for 7 days on Day 11-17 of the estrous cycle (day 0 was the day of ovulation). In experiment 2, goats were administered ACTH (0.625 IU/10 kg of body weight, n = 6) or saline (n = 6) intramuscularly twice a day on Day 11-24 of the estrous cycle. Blood samples were collected 0, 0.5, and 6 h after first administration to determine the circulating cortisol concentrations. Hair was clipped at 0, 1, and 2 months after the start of administration. In both experiments, the plasma cortisol concentration increased at 0.5 h and returned to baseline at 6 h after ACTH administration. During the experiments, estrus was observed in most animals in ACTH and saline groups (6/6 and 4/6 in experiment 1 and 5/6 and 6/6 in experiment 2, respectively) and ovulation was observed in all goats examined. However, the number of ovulatory follicles was significantly different between the ACTH and saline groups, and the maximal diameter of ovulatory follicles tended to be different (P = .07) between the ACTH and saline groups. In experiment 1, the hair cortisol concentration was not influenced by the ACTH administration throughout the sampling period. In experiment 2, the hair cortisol concentration in the ACTH group was greater at 1 month after administration than the pre-administration value, but was not significantly different at 2 months. These results suggest that repeated ACTH administration affects the development and ovulatory process of ovarian follicles and analysis of the hair cortisol concentration can be used for assessing relatively long-term changes in cortisol concentration in the circulation.

Evaluation of criteria for optimal time AI postulated by estrous signs in lactating dairy cows kept in tie-stalls.

Relaxation of the intravaginal part of the uterus is obvious around 6 to 18 h before ovulation, and this is considered the optimal time for artificial insemination (AI), as demonstrated in recent studies. Estrous signs have been suggested as useful criteria for determining the optimal time for AI. Therefore, this study evaluated the usefulness of estrous signs, particularly the relaxation of the intravaginal part of the uterus, as criteria for determining the optimal time for AI. A Total of 100 lactating Holstein-Friesian cows kept in tie-stall barns were investigated. AI was carried out based on the criterion for the optimal time for AI (optimal group), and earlier (early group) and later (late group) than the optimal time for AI, determined on the basis of estrous signs. After AI, ovulation was assessed by rectal palpation and ultrasonographic observation at 6-h intervals. For 87.5% (35/40) of cows in the optimal group, AI was carried out 24-6 h before ovulation, which was previously accepted as the optimal time for AI. AI was carried out earlier (early group) and later (late group) than optimal time for AI in 62.1% (18/29) and 71.0% (22/31) of cows, respectively. The conception rate for the optimal group was 60.0%, and this conception rate was higher than that for the early group (44.8%) and late group (32.2%), without significance. Further, the conception rate of the optimal group was significantly higher than the sum of the conception rates of the early and late groups (38.3%; 23/60) (P < 0.05). These results indicate that the criteria postulated, relaxation of the intravaginal part of the uterus and other estrous signs are useful in determining the optimal time for AI. Furthermore, these estrous signs enable the estimations of stages in the periovulatory period.

Endometrial adenocarcinoma with choriocarcinomatous differentiation in the uterus of a goat.

An 11-year-old female goat had invasive and metastatic endometrial adenocarcinoma in the uterus. There was a notable proliferation of endometrial epithelial cells in a tubular growth pattern, with a desmoplastic response. The endometrial epithelial tumor cells metastasized to the kidney, liver and lung. In contrast to the primary and metastatic tumor cells, pleomorphic tumor cells with a choriocarcinoma-like growth pattern infiltrated the mesometrium. Cell proliferation activity was high in both types of tumor cells. Both types of tumor cells expressed cytokeratins AE1/AE3, 7 and CAM5.2; choriocarcinomatous cells also had positive immunoreactions to human chorionic gonadotropin, human placental alkaline phosphatase and α-inhibin. The present case was diagnosed as endometrial adenocarcinoma with choriocarcinomatous differentiation.

Comparison of productive and reproductive performance and hair cortisol levels between Brown Swiss cross-bred and Holstein cows housed in the same barn.

The productive and reproductive characteristics of Brown Swiss (B) cross-bred cows were investigated by comparing with those of Holstein (H) cows housed in the same barn. Additionally, their hair cortisol levels were analyzed to evaluate the extent of stress experienced during dry and lactation periods. B cross-bred cows had lower milk yields and higher milk fat rates than H cows. Reproductive records showed that days from parturition to first artificial insemination (AI) in B cross-bred (n = 16) and H (n = 27) cows were not significantly different, but conception rate at first AI of B cross-bred cows tended to be higher than that of H cows. Percentage of B cross-bred cows that resumed ovarian cyclic activity within 45 days after parturition was higher than that of H cows (6/6 (100%) and 5/11 (45.5%), P < 0.05), and B cross-bred cows had higher body condition scores at that time. Hair cortisol level at 60 to 90 days after parturition in H cows increased significantly compared with in the dry period, and it was higher than that of B cows during the same period. These results suggest that B cross-bred cows experience less metabolic stress during early lactation, which may result in earlier resumption of reproductive function.

Effect of investigational kisspeptin/metastin analog, TAK-683, on luteinizing hormone secretion at different stages of the luteal phase in goats.

This study aimed to examine the response of luteinizing hormone (LH) secretion and ovarian steroid profile to TAK-683, an investigational metastin/kisspeptin analog, through treatment during different stages of the luteal phase in goats. Nine cycling Shiba goats (4.4 ± 2.3 years old) were assigned to early luteal phase (ELP, n = 4), mid-luteal phase (MLP, n = 4), and control (n = 5) groups. The ELP and MLP groups were administered 50 µg of TAK-683 intravenously on either day 5 or between days 7-14 after ovulation, respectively. The control group received vehicle between days 7-14 after ovulation. Blood samples were collected at 10-min (2-6 h), 2-h (6-24 h), and 24-h (24-96 h) intervals after treatment. Significant increases in plasma LH concentration were detected during the periods of 3 to 5 h and 2 to 5 h in the ELP and MLP groups, respectively. Estradiol concentrations continuously increased with the rise of basal LH secretion after TAK-683 treatment in two goats of the ELP group with a surge-like release of LH, but not in the goats without LH surge, i.e. the MLP and control group ones. Plasma progesterone concentration and the lengths of estrous cycle in all groups did not change significantly from the time before and after treatment. Present findings indicate that the responses of LH and ovarian steroids to treatment with TAK-683 depend on the stage of the luteal phase of the estrous cycle. We suggest that the stimulatory effects of TAK-683 on LH secretion are reduced in the process leading to the mid-luteal phase in cycling goats.

An administration of TAK-683 at a minimally effective dose for luteinizing hormone stimulation under the absence of the ovary induces luteinizing hormone surge in ovary-intact goats.

The present study aimed to evaluate hormonal responses and their association with the TAK-683 blood concentrations in goats administered TAK-683 at a low dose, which had been previously determined as the minimally effective dose for luteinizing hormone (LH) stimulation in ovariectomized goats. In Experiment 1, 5 µg of TAK-683 treatment had no significant stimulatory effect on LH secretion in ovariectomized Shiba goats (n = 4). In Experiment 2, cycling goats received the treatment of prostaglandin F2α and progesterone-releasing controlled internal drug releasing (CIDR) to induce the follicular phase, then they were treated with 5 µg of TAK-683 (hour 0) intravenously (n = 4, IV) or subcutaneously (n = 3, SC) or with vehicle intravenously (n = 4, control) at 12 h after CIDR removal. Blood samples were collected at 10-min (-2-6 h), 2-h (6-24 h), or 6-h (24-48 h) intervals. Ovarian ultrasonographic images were assessed daily to confirm ovulation after the treatment. A surge-like release of LH was immediately observed after injection in all animals in the IV (peak time: 4.2 ± 0.6 h, peak concentration: 73.3 ± 27.5 ng/ml) and SC (peak time: 4.6 ± 0.4 h, peak concentration: 62.6 ± 23.2 ng/ml) groups, but not in the control group. Ovulation was detected within 3 days after TAK-683 injection in all animals in the IV and SC groups, and the interval period from TAK-683 administration to ovulation in the IV group was significantly (P < 0.05) shorter than that of the control group. No significant changes were observed between the IV and SC groups in terms of luteal diameter and blood progesterone levels after ovulation. The present findings suggest that the involvement of one or more ovarian factor(s) is indispensable for a TAK-683-induced LH surge leading to ovulation in goats.