Effects of season and ovarian status on the outcome of long-term progesterone-based estrus synchronization protocols and ovulatory follicle development in Santa Inês ewes under subtropical conditions

2016 ◽  
Vol 85 (3) ◽  
pp. 452-460 ◽  
Author(s):  
M.E.F. Oliveira ◽  
H. Ayres ◽  
L.G. Oliveira ◽  
F.F.P.C. Barros ◽  
E. Oba ◽  
...  
Keyword(s):  
Follicle Development ◽  
Estrus Synchronization ◽  
Ovarian Status ◽  
Ovulatory Follicle ◽  
Santa Inês

scholarly journals Effect of different protocols for estrus synchronization on reproductive performance of Santa Inês ewes under Amazon environmental conditions

2020 ◽  
Vol 43 ◽  
pp. e48954
Author(s):  
Regina Oliveira da Silva ◽  
Roseane Pinto Martins de Oliveira ◽  
André Ferreira Silva ◽  
Franklyn Ferreira de Oliveira ◽  
João Paulo Ferreira Rufino ◽  
...  
Keyword(s):  
Experimental Design ◽  
Pregnancy Rate ◽  
Reproductive Performance ◽  
Environmental Conditions ◽  
Pregnancy Rates ◽  
Estrus Synchronization ◽  
Test Results ◽  
Short Term ◽  
Santa Inês

 The objective of this study was to evaluate the effect of different hormonal protocols on the reproductive performance of Santa Inês ewes in Amazon environmental conditions. Twenty-two Santa Inês ewes between 3 and 4 years-old were distributed in a randomized block experimental design, where the treatments consisted of two protocols for estrus synchronization (short and long) with eleven animals each. Data on the occurrence of estrus were described for each protocol. Data of estrus, pregnancy, and prolificity were firstly subjected to ANOVA and a subsequent Tukey’s test. Results were considered significant at p ≤ 0.05. The short-term protocol presented an interesting successful rate, where above 70% ewes tested had estrus. The long-term protocol also achieved a high successful rate, where above 80% ewes tested had estrus. However, comparing the protocols, the long-term protocol presented better results of positive estrus and pregnancy rates in ewes. Thus, it can be concluded that both protocols presented satisfactory results regarding estrus manifestation, and prolificity (lambs produced per ewe). However, under Amazon environmental conditions, the long-term protocol presented better results regarding positive manifestation of estrus and pregnancy rate.

330 Effect of inducing high or low progesterone concentrations during ovulatory follicle development on double ovulation and fertility of lactating dairy cows

2016 ◽  
Vol 94 (suppl_2) ◽  
pp. 155-155
Author(s):  
J. P. N. Martins ◽  
D. Wang ◽  
N. Mu ◽  
A. P. Martini ◽  
G. F. Rossi ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Follicle Development ◽  
Lactating Dairy Cows ◽  
Ovulatory Follicle

scholarly journals COMPARISON OF LONG-TERM PROGESTERONE-BASED PROTOCOL ON REPRODUCTIVE PERFORMANCE OF PREPUBERTAL AND PUBERTAL BEEF HEIFERS.

2014 ◽  
Vol 19 (1) ◽  
Author(s):  
Emanoel Faleiros Silveira ◽  
Luiz Ernandes Kozicki ◽  
Marcio Saporski Segui ◽  
Romildo Romualdo Weiss ◽  
Ivo Walter Santos ◽  
...  
Keyword(s):  
Ultrasound Examination ◽  
Prostaglandin F2α ◽  
Estradiol Benzoate ◽  
Pregnancy Rates ◽  
Estrus Synchronization ◽  
Device Removal ◽  
Timed Artificial Insemination ◽  
Red Angus ◽  
Natural Service

The aim of this study was to investigate estrus synchronization in prepubertal and pubertal heifers (crossbred ½ Nelore x Red Angus - commercial herd) submitted to a long-term progesterone-based protocol for timed artificial insemination (TAI), as well as overall pregnancy rates. Four hundred forty-seven heifers underwent ultrasound examination of the ovaries and were assigned to one of 3 groups: (1) prepubertal heifers (PPNS; n = 114) with ovarian follicles <8 mm in diameter and no corpus luteum (CL) that were submitted to natural service (NS) by bulls for 10 days; (2) prepubertal heifers (PPTAI; n = 124) with follicles <8 mm in diameter and no CL that underwent estrus synchronization with injection of 4.0 mg estradiol benzoate (EB) and insertion of a controlled-release intravaginal progesterone (P4) device containing 0.558 g P4 on d 0, followed by P4 device removal and injection of 150 mg prostaglandin F2α and 0.6 mg estradiol cypionate (ECP) on d 8, and TAI on d 10; and (3) pubertal heifers (PTAI; n = 209) with follicles >8 mm in diameter and/or a CL that underwent the same protocol as PPTAI heifers. Overall pregnancy rate was determined by transrectal ultrasonography on d 45 after NS or TAI. Data were analyzed using the FREQ procedure of SAS (SAS Inst. Inc., Cary, NC). Pregnancy rates were as follows: 20.1% in PPNS, 37.0% in PPTAI, and 48.5% in PTAI (P < 0.05). In conclusion, TAI after estrus synchronization with a hormonal protocol using EB and ECP in prepubertal and pubertal heifers resulted in higher pregnancy rates than prepubertal heifers exposed to natural service, and exposure of prepubertal heifers to a long-term progesterone-based protocol effectively synchronized estrus.

scholarly journals Level of circulating concentrations of progesterone during ovulatory follicle development affects timing of pregnancy loss in lactating dairy cows

2018 ◽  
Vol 101 (11) ◽  
pp. 10505-10525 ◽  
Author(s):  
J.P.N. Martins ◽  
D. Wang ◽  
N. Mu ◽  
G.F. Rossi ◽  
A.P. Martini ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Pregnancy Loss ◽  
Follicle Development ◽  
Lactating Dairy Cows ◽  
Ovulatory Follicle

scholarly journals A review of the physiology behind letrozole applications in infertility: are current protocols optimal?

2020 ◽  
Vol 37 (9) ◽  
pp. 2093-2104
Author(s):  
Bruce I. Rose ◽  
Samuel E. Brown
Keyword(s):  
Ovulation Induction ◽  
Medical Literature ◽  
Negative Impact ◽  
Follicle Development ◽  
Antral Follicles ◽  
Ovulatory Follicle ◽  
Menopausal Women ◽  
Post Menopausal ◽  
Cell Mitosis ◽  
Physiologic Data

Abstract Letrozole is a targeted aromatase inhibitor which has primarily been used in post-menopausal women with breast cancer. Recently, it has been utilized in infertile pre-menopausal women because of its ability to enhance FSH production for ovulation induction. However, the ovarian follicle’s response to FSH is only a part of the endocrine events occurring in a developing follicle. The health of the small antral follicles is driven primarily by androgens, which contribute to granulosa cell mitosis, sensitivity to FSH, and resistance to atresia. In contrast, elevated androgens in the late antral to pre-ovulatory follicle have a negative impact on follicle health and lead to atresia and cystic follicle formation. This ovarian physiologic data suggests that current applications of letrozole to infertility may be squandering some of the primary benefits available in using letrozole to promote follicle development. Four applications of letrozole to infertility that have appeared in the medical literature are reviewed. Androgen-related benefits are reviewed and various questions put forward about how letrozole could be more effectively used to help patients in these settings.

scholarly journals Post-partum reproductive activity and estrus synchronization responsiveness in anglonubian x sprd fed with dried carnauba wax palm fruit (Copernicia prunifera) long term

2015 ◽  
Vol 36 (4) ◽  
pp. 2619 ◽  
Author(s):  
Aline Maia Silva ◽  
Cláudio Henrique de Almeida Oliveira ◽  
César Carneiro Linhares Fernandes ◽  
Liliane Moreira Silva ◽  
Diana Celia Nunes-Pinheiro ◽  
...  
Keyword(s):  
Post Partum ◽  
Reproductive Activity ◽  
Estrus Synchronization ◽  
Palm Fruit ◽  
Carnauba Wax

Effects of treatment with a gonadotrophin-releasing hormone analogue on follicle development in dairy cows fed one of two different diets

2001 ◽  
Vol 26 (2) ◽  
pp. 451-455
Author(s):  
E.C.L. Bleach ◽  
C.L. Moore ◽  
H.J. Zeale ◽  
P.G. Knight
Keyword(s):  
Dairy Cows ◽  
Luteal Phase ◽  
Cycle Length ◽  
Crude Protein ◽  
Oestrous Cycle ◽  
Follicle Development ◽  
Releasing Hormone ◽  
Ovulatory Follicle ◽  
Metabolisable Energy ◽  
Phase Length

AbstractFollicle development occurs in two or three waves during the bovine oestrous cycle. Artificially extending the duration of ovulatory follicle dominance influences pregnancy rates in cattle, as does the interval from emergence to oestrus in dairy cows undergoing spontaneous oestrous cycles. The objectives of the presented study were to determine whether the interval from ovulatory follicle emergence to oestrus might be altered by diet and/or gonadotropin-releasing hormone (GnRH) treatment. Lactating primiparous Holstein/Friesian cows (n=21) were randomly allocated to one of two diets at calving (Diet 1, n=ll, DM 480 g/kg, metabolisable energy 12.0 MJ/kg DM crude protein 178 g/kg DM, oil B 48 g/kg DM, neutral detergent fibre 318 g/kg DM and diet 2, n=10, DM 440 g/kg, metabolisable energy 12.1 MJ/kg DM, crude protein 172 g/kg DM, oil B 40 g/kg DM, neutral detergent fibre 300 g/kg DM). From 10 days after observed oestrus (oestrus 1), ovarian follicular and luteal development was monitored by daily transrectal ultrasonography until the subsequent oestrus and ovulation. A GnRH analogue was injected (i.m.; 10 μg) 12 days after oestrus 1 in 6 cows fed diet 1 and 5 cows fed diet 2. Oestrous cycle length was longer (p<0.05) in control cows fed diet 1 than those fed diet 2. Treatment with GnRH increased (p<0.005) cycle length in cows fed diet 2 but not those fed diet 1. Increases in cycle length observed were associated with longer luteal phase length. Follicular phase length was reduced (p<0.05) by GnRH treatment in cows fed diet 1. Ovulatory follicles emerged later (p<0.05) in control cows fed diet 1 than those fed diet 2. GnRH treatment delayed (p<0.01) the emergence of the ovulatory follicle in cows fed diet 2, this delay was associated with an increase (p<0.05) in the incidence of 3 follicle waves in oestrous cycles following GnRH treatment. The interval from emergence of the ovulatory follicle to the subsequent oestrus was similar among the treatment groups. We conclude that treatment with GnRH during the mid-luteal phase may delay the emergence of the ovulatory follicle. However, the response is dependent on diet fed. Where ovulatory follicle emergence is delayed, the interval from emergence to the subsequent oestrus was unaffected since oestrous cycle length is extended.

Efficiency of different hormonal treatments for estrus synchronization in tropical Santa Inês sheep

2016 ◽  
Vol 48 (3) ◽  
pp. 545-551 ◽  
Author(s):  
Tarcísio Alves Texeira ◽  
Jeferson Ferreira da Fonseca ◽  
Joanna Maria Gonçalves de Souza-Fabjan ◽  
Luciano de Rezende Carvalheira ◽  
Daniel Andrews de Moura Fernandes ◽  
...  
Keyword(s):  
Estrus Synchronization ◽  
Santa Inês ◽  
Hormonal Treatments

scholarly journals Ovarian status dictates the neuroinflammatory and behavioral consequences of sub-chronic stress exposure in middle-aged female mice

2019 ◽  
Author(s):  
Rand S. Eid ◽  
Stephanie E. Lieblich ◽  
Sarah J. Wong ◽  
Liisa A.M. Galea
Keyword(s):  
Frontal Cortex ◽  
Chronic Stress ◽  
Ovarian Hormones ◽  
Stress Exposure ◽  
Middle Aged ◽  
Aged Mice ◽  
Ovariectomized Mice ◽  
Ovarian Status ◽  
Immunomodulatory Properties

AbstractOvarian hormones influence the outcomes of stress exposure and are implicated in stress-related disorders including depression, yet their roles are often complex and seemingly contradictory. Importantly, depression and stress exposure are associated with immune dysregulation, and ovarian hormones have immunomodulatory properties. However, how ovarian hormones can influence the inflammatory outcomes of stress exposure is poorly understood. Here, we examined the effects of long-term ovariectomy on the behavioral and neuroinflammatory outcomes of sub-chronic stress exposure in middle-aged mice. Briefly, sham-operated and ovariectomized mice were assigned to non-stress groups or exposed to 6 days of variable stress. Mice were assessed on a battery of behavioral tests, and cytokine concentrations were quantified in the frontal cortex and hippocampus. In the frontal cortex, postsynaptic density protein-95 expression was examined as an index of excitatory synapse number and/or stability, and phosphorylated mitogen-activated protein kinases (MAPKs) were measured to explore potential cell signaling pathways elicited by stress exposure and/or ovarian hormones. Long-term ovariectomy modified the central cytokine profile by robustly reducing cytokine concentrations in the frontal cortex and modestly increasing concentrations in the hippocampus. Under non-stress conditions, long-term ovariectomy also reduced extracellular signal-regulated kinase (ERK) phosphoprotein expression in the frontal cortex and increased some measures of depressive-like behavior. The effects of sub-chronic stress exposure were however more pronounced in sham-operated mice. Notably, in sham-operated mice only, sub-chronic stress exposure increased IL-1β and IL-6:IL-10 ratio in the frontal cortex and hippocampus and reduced pERK1/2 expression in the frontal cortex. Further, although sub-chronic stress exposure increased anhedonia-like behavior regardless of ovarian status, it increased passive-coping behavior in sham-operated mice only. These data indicate that long-term ovariectomy has potent effects on the central cytokine milieu and dictates the neuroinflammatory and behavioral effects of sub-chronic stress exposure in middle-aged mice. These findings therefore suggest that the immunomodulatory properties of ovarian hormones are of relevance in the context of stress and possibly depression.

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