Close contact with spontaneously cycling Saint Croix ewes triggers cyclic activity in seasonally anestrous Suffolk ewes

2016 ◽  
Vol 56 (11) ◽  
pp. 1816 ◽  
Author(s):  
Agustín Orihuela ◽  
Neftalí Clemente ◽  
Rodolfo Ungerfeld

In domestic goats, oestrous activity may be induced by close contact with cyclic females. As tropical breeds of sheep show light seasonality or are even unaffected by season, the purpose of this study was to examine the hypothesis that cyclic activity may be induced in anestrous Suffolk ewes by close contact with spontaneously cycling Saint Croix ewes. The experiment was conducted with 17 anestrous Suffolk ewes that were assigned to one of two groups. Although Suffolk ewes in the Control group (n = 9) remained isolated, those of the treated group (n = 8) were joined (Day 0) and maintained in close contact with 20 Saint Croix ewes for 38 days. Serum progesterone concentration was measured in all ewes in blood samples collected on Days –8, –2, 8, 13, 18, 23, 28, 33 and 38. Before Day 0, 17/20 Saint Croix ewes were cycling, but no Suffolk ewe had luteal levels of progesterone. By Day 13, more treated than Control Suffolk ewes had progesterone luteal concentrations (8/8 vs 1/9; P = 0.0004). It was concluded that spontaneously cycling Saint Croix ewes induce cyclic activity in anestrous Suffolk ewes.

1996 ◽  
Vol 150 (1) ◽  
pp. 93-98 ◽  
Author(s):  
Y Nakamura ◽  
H Tamura ◽  
M Ono ◽  
K Shimamura ◽  
N Sugino ◽  
...  

Abstract The purpose of this study was to examine the possible mechanism through which RU486 induces luteolysis during the late-luteal phase in pseudopregnant (PSP) rats. PSP rats received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight) or sesame oil alone once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10, 11 and 12 and assayed for progesterone content. To examine the possible action of RU486 through a uterine and/or a pituitary (prolactin-dependent) mechanism, PSP rats and chronic hysterectomized PSP rats which had been hysterectomized before PSP induction received a subcutaneous injection of RU486 in sesame oil (5 mg/kg body weight), sesame oil alone, prolactin in 50% polyvinylpyrrolidone (15 IU/day), or RU486 and prolactin once a day between day 9 and day 11 of pseudopregnancy. Serial blood samples were collected on days 5, 9, 10 and 11 and assayed for progesterone content. Blood samples were also collected at 0400 h on day 12 and used for prolactin and progesterone determinations. To examine the direct effect of RU486 on corpus luteum and/or pituitary, hysterectomized rats underwent hypophysectomy and pituitary autotransplantation on dioestrus 1 and received a subcutaneous injection of RU486 in sesame oil or sesame oil alone for 3 days between day 21 and day 23 after surgery. Serial blood samples were collected on days 10, 21, 22, 23 and 24 and assayed for progesterone and prolactin contents. In ordinary PSP rats, serum progesterone levels were significantly (P<0·01) lower in the RU486-treated group than in the control group (9 ± 1 vs 53 ± 7 ng/ml; mean ± s.e.m.) on day 11. Serum prolactin levels at 0400 h on day 12 of pseudopregnancy were significantly (P<0·05) lower in the RU486-treated group than in the control group (16 ±4 vs 154 ±44 ng/ml; mean ± s.e.m.). The concomitant prolactin treatment reversed the luteolytic effects of RU486 on day 11 of pseudopregnancy. In hysterectomized PSP rats, RU486 also suppressed serum prolactin levels, and the concomitant prolactin treatment again reversed the luteolytic effects of RU486. In hysterectomized rats which were hypophysectomized and pituitary autotransplanted, RU486 treatment did not induce any significant changes in serum progesterone and prolactin levels. These results indicated that RU486 induced luteolysis during the late-luteal phase in PSP rats by suppressing prolactin secretion via a hypothalamic mechanism. Journal of Endocrinology (1996) 150, 93–98


Author(s):  
M. M. Chaudhary ◽  
C. T. Khasatiya ◽  
S. B. Patel ◽  
S. S. Chaudhary ◽  
V. B. Atara ◽  
...  

The serum progesterone and estradiol profiles during synchronization of estrus by buck effect and PGF2α treatments were monitored in Surti does. Total eighteen non-pregnant does selected were evenly divided into 3 groups, 6 does in each group. The does of Group I were teased with a sexuallyactive- apronized buck; and those of Group II were treated with PGF2α, i.e., Inj. Lutalyse® @ 7.5 mg/doe IM twice 11 days apart, while the Group III served as untreated control. Blood samples were collected from all the animals on day 0 (before 1st PGF2α injection), 3rd day (during treatment), 11th day (before 2nd PGF2α injection), 14th day (after treatment) and 40th day (post-service) by jugular vein puncture. The serum separated was stored at -20°C till further analysis. In all the three groups, 83.33% does, conceived at first service in the sampling cycle. The overall mean serum progesterone concentration of Group I does (5.82±0.72 ng/ml) was significantly higher (p less than 0.01) as compared to Group II (2.93±0.38 ng/ml) and III (2.88±0.30 ng/ml). Similarly, the overall mean serum progesterone concentration of Surti does on day 0 (2.65±0.46 ng/ml), 3rd (2.56±0.80 ng/ml), 11th (4.45±0.84 ng/ml) and 14th (3.40±0.63 ng/ml) did not differ significantly, but the overall mean level at day 40 (6.31±0.45 ng/ml) was significantly (p less than 0.01) higher, because most of animals became pregnant at that time. The overall mean serum oestradiol-17β levels of Group I (24.40±2.98 pg/ ml) was significantly higher (p less than 0.01) than in Group II (15.77±1.77 pg/ml) and III (12.21±1.45 pg/ ml). On the other hand, the overall mean serum oestradiol-17β levels of Surti does on day 0 (12.89±1.21 pg/ml), 3rd (15.84±1.74 pg/ml), 11th (14.81±1.96 pg/ml), 14th (22.15±2.97 pg/ml) and 40th (21.64±5.16 pg/ml) did not differ significantly (p>0.05) and the slightly higher overall mean level found at 40th day might be the influence of the non-pregnant does at first service in the cumulative animals. The hormonal profile reflected the initiation of cyclicity and establishment of pregnancy in treated and control animals.


2016 ◽  
Vol 203 (1) ◽  
pp. 29-54 ◽  
Author(s):  
Hanan H. Abd-Elhafeez ◽  
Doaa M. Mokhtar ◽  
Ahmed H.S. Hassan

Telocytes (TCs) are a special type of interstitial cell with characteristic cellular processes that are described in many organs. The current study aimed to investigate TCs in seminal vesicles of the Soay ram responding to melatonin treatment during the nonbreeding season by conventional immunohistochemical stains, and to detect the ultrastructural and morphometrical changes of TCs. TCs in the control group showed a broad range of staining affinity and also reacted positively to CD117/c-kit, CD34, desmin, S-100 protein, and progesterone and estrogen receptors alpha, while after melatonin treatment a strong reaction against these 6 antibodies was recorded. Electron microscopically, TCs in the control group were characterized by a small cell body with distinct long cytoplasmic extensions called telopodes (Tps). Tps had alternation of the thin segment (podomers) and dilated segments (podoms), in which the latter accommodate mitochondria, rough endoplasmic reticulum and caveolae. TCs and their Tps were interconnected by homo- and heterocellular junctions and form a wide network to communicate between different cell types. Tps showed close contact with immune cells, progenitor stem cells, smooth muscle cells and other interstitial cells. Melatonin caused a significant increase in the number of TCs, length of Tps, and number and diameter of secretory vesicles. Also, the melatonin-treated group showed exaggerated secretory activity in the form of a massive release of secretory vesicles from Tps. Moreover, Tps showed an increase in their contact with blood and lymphatic capillaries, nerve endings and Schwann cells. In addition, the shedding of secretory structures (exosomes, ectosomes, and multivesicular bodies) was greater from Tps, which were involved in paracrine signaling in the melatonin-treated group. The length and ramifications of Tps together with the intercellular junctions and the releasing of shed vesicles or exosomes assumed an essential role of TCs in intercellular signaling and coordination. On the basis of their distribution and morphology, we investigated whether the different locations of TCs could be associated with different roles.


2019 ◽  
Vol 43 (2) ◽  
pp. 1-5
Author(s):  
SaifAldeen Abd-Alhadi ◽  
Najlaa Sami S. Ibrahim

The present study was conducted to measure the concentration of progesterone throughout gestation and parturition in control and treated bitches. Thirty anestrus bitches aged 3 - 6 years and weighing 19.5 - 26 kg were used in this study. The bitches were divided equally into three groups as follows: the 1st group as a control group  without treatment, the 2nd group as a treated group anestrus bitches treated orally with 0.125 mg/kg BW bromocriptine (Parlodel) twice daily, and the 3rd group treated orally by 0.012 mg/kg BW cabergoline (Dostinex) until the appearance of estrus signs. The results showed that the number of responded animals were in proestrus bleeding and became pregnant and newborn 70%, 60% and 50% for control, bromocriptine, and cabergoline treated groups, respectively. In addition, there were no significant differences (P ≤ 0.01) in progesterone concentration between the control and treated pregnant bitches. It can be concluded that both medicines bromocriptine and cabergoline have no effect on progesterone levels during pregnancy period in bitches.


1998 ◽  
Vol 26 (2) ◽  
pp. 93-97 ◽  
Author(s):  
T Endo ◽  
K Kanayama

The involvement of the immune system in changes in luteal function was evaluated in rabbits. Pseudopregnancy was induced in 10 females and the spleens (considered to be the source of macrophages) of five were excised on day 7 of pseudopregnancy, while the five controls had sham splenectomies. Subsequent changes in serum progesterone concentrations were measured as an indicator of luteal function and luteolysis. A second pseudopregnancy was induced 31 days after splenectomy. The first pseudopregnancy was prolonged and during the second pseudopregnancy the serum progesterone concentrations on days 3 and 7 were much lower in the splenectomy group than in the control group. On day 14 of the second pseudopregnancy, the serum progesterone concentration markedly decreased in the control group while it remained almost at the level of day 7 in the splenectomy group. These results suggest that splenectomy suppresses the expression of luteal function and delays luteolysis in rabbits.


2012 ◽  
Vol 24 (1) ◽  
pp. 140
Author(s):  
H. Stinshoff ◽  
E. Onnen-Lübben ◽  
S. Wilkening ◽  
A. Hanstedt ◽  
H. Bollwein ◽  
...  

Shortly after parturition the metabolic situation of high-yielding dairy cows is often dominated by a negative energy balance. These effects affect the whole animal and may especially be detected in the reproductive tract, where they result in reduced fertility. An oral supplementation with dietary fats is often used to counteract by reducing milk fat content and, thus, supplying the individual animal with an increased amount of energy. The focus of the present study was to analyse the effects of an oral supplementation with conjugated linoleic acids (CLA) on corpus luteum (CL) function. Healthy Holstein-Friesian cows and heifers were randomly allocated to 2 treatment groups (Group 1: 50 g of CLA day–1 per animal, 2 heifers, 6 cows; Group 2: 100 g of CLA day–1 per animal, 2 heifers, 6 cows) and 1 control group (Ctl; 0 g of CLA day–1 per animal, 3 heifers, 4 cows). Feeding of the supplement began shortly after calving. After calving, all animals were subjected to a standard synchronisation protocol and experienced AI on Day 59 ± 3. Following AI, transvaginal biopsies of the corpus luteum were obtained of pregnant (Group I: n = 4; Group II: n = 4; Ctl: n = 4) and nonpregnant (Group I: n = 4; Group II: n = 4; Ctl: n = 3) animals on Days 6, 13 and 20 post-AI. Animals deemed pregnant on Day 28 were again biopsied on Day 42. Additionally, blood samples were taken from the vena sacralis mediana at the time of each biopsy. The biopsies were analysed regarding the relative abundance of 8 gene transcripts (VEGF, ECE1, PLA2G4A, PTGS2, PTGFR, PPARG, STAR and HSD3B1) via RT-qPCR. Blood samples were analysed for their concentration of progesterone through a radioimmunoassay (RIA). Statistical analysis for both datasets was performed via a 3-way ANOVA with adjoining Tukey test. The expression of 7 of these genes was affected by 1, 2, or all 3 of the following factors: day of cycle (VEGF, ECE1, PLA2G4A, PTGFR, STAR and HSD3B1), pregnancy status (ECE1, PTGFR and HSD3B1) and CLA supplementation (ECE1, PTGS2, PTGFR, STAR and HSD3B1). The effects of the CLA supplementation could be seen as a down-regulation in the mentioned gene transcripts. Progesterone concentrations differed significantly in dependency of the pregnancy status (significantly higher in pregnant vs nonpregnant individuals) of the animals, as well as during the days of the oestrous cycle (physiological progesterone curve with highest values on Day 13 of these samples). An effect of the oral supplementation with CLA could be detected during the early luteal phase (Day 6) where animals that had received 100 g of CLA day–1 had a significantly lower blood progesterone concentration than those receiving 50 g of CLA day–1 or no CLA. In conclusion, dietary CLA supplementation has an effect on luteal gene expression and functionality. The authors thank the DFG (German Research Foundation) for their financial support (PAK286/1; WR154/1-1).


2016 ◽  
Vol 5 (06) ◽  
pp. 4597
Author(s):  
Janardhan Reddy Ippala* ◽  
Ashish Mishra ◽  
Mondal S. ◽  
David G. C. ◽  
Ravi Kiran G. ◽  
...  

The aim of this study was to investigate the effects of red spectrum of light (650nm, treated n=12) and normal spectrum of light (450nm control=12) on circulating concentrations of luteinizing hormone (LH), progesterone (P4), estradiol (E2β), GnRH mRNA, pause days and egg production in birds later in the reproductive period from 92-102weeks of age. Twenty-four White Leghorn birds of same age group were divided into two groups of 12 in each as control and treated. Birds in the control group were exposed to normal spectrum of light (450nm of length) and birds in the treated group were exposed to red spectrum of light (650nm, treated n=12). Egg production and inter sequence pauses were recorded daily from both the groups. Plasma LH, E2β and P4 concentrations were estimated in blood samples collected at weekly intervals. At 97th weeks of age, blood samples from treated and control birds were obtained every 3 h for 36 h to study the surges of LH. It was found that plasma GnRH was higher (p < 0. 01) in treated birds with high concentrations of LH, its 3 h LH surges, E2β and P4 in plasma. Higher egg production, less pause days in treated birds may be the result of high GnRH associated with positively correlated responses of high concentrations of LH (with regular interval and duration of LH surges), E2β and P4 concentration required for completion of egg formation and oviposition. In conclusion, red spectrum of light enhanced GnRH mRNA (p < 0. 01), increased (p < 0. 01) steroid hormones and LH surges, for egg formation and oviposition and enabled the birds to lay more eggs even later in the productive period with the available resources under normal husbandry practices. 


2019 ◽  
Vol 43 (2) ◽  
pp. 1-5
Author(s):  
SaifAldeen Abd-Alhadi Nawaf

The present study was conducted to measure the concentration of progesterone throughout gestation and parturition in control and treated bitches. Thirty anestrus bitches aged 3-6 years and weighting 19.5-26 kg were used in this study. The bitches were divided equally into three groups as follows: the 1st group as a control group  without treatment, the 2nd group as a treated group anestrus bitches treated orally with 0.125 mg/kg BW bromocriptine (Parlodel) twice daily, and the 3rd group treated orally by 0.012 mg/kg BW cabergoline (Dostinex) until appearance of estrus signs. The results showed that the number of responded animals were in proestrus bleeding and became pregnant and new born 70%, 60% and 50% for control, bromocriptine, and cabergoline treated groups, respectively. In addition, there were no significant differences (P≤0.01) in progesterone concentration between the control and treated pregnant bitches. It can be concluded that both medicines bromocriptine and cabergoline have no effect on progesterone levels during pregnancy period in bitches.


2013 ◽  
Vol 12 (1) ◽  
pp. 183
Author(s):  
A.A. Omar

This study was conducted on10 healthy Iraqi Awassi ewes that examined by ultrasonography technique, with ages between 2 to 3 years, presented at the farm of the College of Veterinary Medicine, Al-Anbar University, Fallujah, during the period from the end of the February until the half of the March 2012. Vaginal sponges saturated with 40mg Flurogestone acetate were inserted in the vagina of each tested animals in order to induce estrus For synchronization for 14 days, at day 13of the experiment the animals were injected i.m. by Equine chorionic gonadotropine eCG (500 i.u.) then the sponges were removed and the animals injected i.m. with (200 i. u.) of Human chorionic gonadotropine (HCG). Blood samples were collected from jugular vein with vacutainer tubes each two days until the experiment was complete. Serum was collected after centrifugation with a speed 3000R/m for 10 minutes. Values of estrogen and progesterone hormones in serum were estimated by Enzyme Linked Immuno Sorbent Assay (ELISA) technique. Values of the estrogen and progesterone in the treated animals were (1.1932 ± 0.02380), (0.9558 ± 0.3282) respectively, while the levels of the two hormones for the control group was (1.1138 ± 0.02295) for the estrogen and (0.8702 ± 0.0152) for the progesterone. There was a significant different between the level of estrogen and progesterone hormones P < 0.05 in a treated group as a compare with the control group. It was concluded from this study that estrus synchronization of the ewes with vaginal sponge affected the values of estrogen and progesterone hormones in the serum


2011 ◽  
Vol 23 (1) ◽  
pp. 257
Author(s):  
K. S. Park ◽  
K. J. Kim ◽  
S. A. Choi ◽  
J. H. Lee ◽  
E. Y. Kim ◽  
...  

Several factors influence the limited application of assisted reproductive technologies (ART) in the canine species. Most problems arise because of the complex nature of reproductive physiology of the dog. For example, dogs are monoestrus, generally exhibiting oestrus only once every 6 month to 1 year. In the canine species, there has been little research on the ART because of difficulties associated with anatomy and reproductive physiology. Because in vitro maturation of canine oocytes has been particularly difficult, in vivo matured oocytes have been used in somatic cell nuclear transfer. However, the number of oocytes that can be obtained using this approach is limited, with ∼6 to 10 good oocytes being obtained per collection. The present study was undertaken to evaluate the effects of different dosages of eCG on folliculogenesis in the dog and to determine the number of oocytes that might be obtained after ovulation. The experimental design involved 3 groups that were treated with different dosages of eCG at the early stage of proestrus; Group A was a nontreatment (control) group, Group B received 200-IU eCG SC injections every day, and Group C was injected with 500 IU of eCG every 2 days until reaching 2 to 3 ng mL–1 serum progesterone concentration, respectively. Dogs in Groups B and C received a 1 000-IU hCG SC injection when progesterone concentrations reached 2 to 3 ng mL–1. The serum progesterone concentration was examined with a Radioimmunoassay Kit (Diagnostic Systems Laboratories Inc., Webster, TX, USA). The day of ovulation was considered as the day when serum progesterone concentration reached 4.0 to 7.2 ng mL–1. Approximately 70 to 76 h after ovulation, the dogs were subjected to the oocyte collection procedure. One-way ANOVA followed by Duncan’s multiple range tests was performed. The significance level was <0.05. In total, 446 oocytes were recovered from 60 bitches, with an average of 6.4 oocytes/dog in Group A (from 49 bitches), 16.6 oocytes/dog in Group B (from 5 bitches), and 8.5 oocytes/dog in Group C (from 6 bitches). The oocytes collection rate (number of oocytes per dog) in Group B was higher (P < 0.05) than those in the other 2 groups. In conclusion, the results showed that eCG treatment with hCG in early-proestrus-stage bitches can result in a greater number of recovered in vivo matured oocytes. This technology could become a useful research tool for canine cloning and ART.


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