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1.
Theriogenology ; 198: 327-331, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638592

RESUMO

Bromocriptine (BRM), a dopamine 2 receptor agonist, is a common drug for inducing estrus in dogs. It is also used for the treatment of some endocrine abnormalities and has some cardiovascular consequences in the patients under treatment. The current study aimed to evaluate its effects on the cardiovascular function of dogs during administration and the subsequent induced estrus cycle. Eight non-pregnant female dogs were assigned into control and treatment groups. The control group (n = 3) were dogs that showed proestrus naturally. The treatment group (n = 5) received oral incremental (µg/kg) doses (100 on days 1 and 2, 200 on days 3, 4, and 400 on days 5 until the proestrus expression) of BRM tablets (2.5 mg; Iran-Hormone Co, Iran). The left ventricle function, carotid blood flow indices, and systolic (SAP) and diastolic (DAP) arterial pressure were recorded every two days. The phases of the cycle were determined using a vaginal smear. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI) had a sharp decline following the administration of BRM (P < 0.05). The carotid PSA, EDV, RI, and pulse index were lower during induced estrus compared to the control (p < 0.05). BRM-induced estrus showed a different pattern of changes compared to the normal cycle from day 9 (p < 0.05) onwards. The cardiovascular effects of BRM remained for days after the termination of administration which may interfere with reproductive functions.


Assuntos
Bromocriptina , Estro , Cães , Animais , Feminino , Velocidade do Fluxo Sanguíneo/fisiologia , Irã (Geográfico)
2.
Biol Sex Differ ; 14(1): 1, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36609535

RESUMO

BACKGROUND: GnRH agonists have been used to halt the development of puberty in children with precocious puberty since the 1980s. Recently, drugs like Lupron Depot® (leuprolide acetate), have been used to suppress pubertal progression in adolescents who are questioning their gender identity. However, few preclinical studies have been conducted to investigate potential effects of using GnRH agonists in this context. METHODS: The present study tested the effects of daily leuprolide treatment (50 µg/kg, postnatal day (PD) 25-50) on pubertal onset in female (i.e., vaginal opening) and male (i.e., preputial separation) Long-Evans rats. The first estrous cycle immediately after vaginal opening was also measured. Sexual behavior and sexual motivation were tested using the partner-preference paradigm. Female rats were tested during the first behavioral estrus after treatment ended (between PD 51-64). Male rats were tested weekly for four consecutive weeks starting three days after treatment ended (PD 53). RESULTS: Consistent with previous findings, leuprolide significantly delayed pubertal onset in both female and male rats. In addition, the first estrous cycle during the treatment period was disrupted by leuprolide, as indicated by a failure to cycle into estrus after vaginal opening until treatment ended. However, leuprolide affected neither sexual motivation nor fertility when female rats were tested within 14 days of leuprolide treatment ending. In contrast, the development of copulatory behavior and sexual motivation was significantly delayed by leuprolide in male rats; however, mature reproductive behavior was observed by the fourth week post-treatment. CONCLUSIONS: Taken together with previous findings, the present results indicate that male rats may be more sensitive to periadolescent leuprolide administration, taking longer to overcome the effects of leuprolide than female rats. Nevertheless, not long after leuprolide treatment is discontinued, sex-typical reproductive physiology and behavior emerge fully in female and male rats, indicating that the drug's effects are not permanent. If translatable to humans, leuprolide may be a reversible option to give adolescents more time to consider their gender identity with minimal long-term effects on sexual development.


Assuntos
Leuprolida , Puberdade Precoce , Humanos , Criança , Ratos , Feminino , Masculino , Animais , Adolescente , Leuprolida/farmacologia , Leuprolida/uso terapêutico , Ratos Long-Evans , Identidade de Gênero , Puberdade Precoce/tratamento farmacológico , Estro
3.
Physiol Behav ; 259: 114053, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36502894

RESUMO

Exposure to males or male urinary scent can induce and accelerate the rate of female estrous cycling in house mice ("Whitten effect"), and this response has been replicated many times since its discovery over 60 years ago. Here, we tested whether exposing female mice to recordings of male courtship ultrasonic vocalizations (USVs) induces estrous cycling, and whether exposure to both male scent and USVs has a stronger effect than to either of these stimuli alone. We conducted our study with 60 wild-derived female house mice (Mus musculus musculus). After singly housing females for 14 days, we monitored estrous stages via vaginal cytology for two weeks while isolated from males or male stimuli. We continued monitoring estrus for two more weeks during experimental exposure to one of four different types of stimuli: (1) clean bedding and background noise playback (negative control); (2) recordings of male USVs (16 min per day) and clean bedding (male USV treatment); (3) soiled male bedding and background noise playback (male odor treatment; positive control); or (4) male USVs and soiled male bedding (male odor and USV treatment). Females were then paired with males to test whether any of the four treatments influenced female reproduction (especially latency to birth). We confirmed that exposure to male odor increased female cycling, as expected, but exposure to recordings of male USVs had no effect on estrus. Females exposed to both USVs and odor went through more cycles compared to controls, but did not differ significantly from exposure to male odor (and background noise). After pairing females with a male, females showing male odor-induced cycling produced their first litter sooner than controls, whereas USVs did not have such an effect. This is the first study to our knowledge to show that male odor induces estrus in wild house mice and to show functional effects on reproduction. Our results do not support the hypothesis that male vocalizations induce female estrus, although we suggest other approaches that could be used to further test this hypothesis.


Assuntos
Odorantes , Vocalização Animal , Camundongos , Masculino , Feminino , Animais , Vocalização Animal/fisiologia , Ultrassom , Estro , Corte
4.
Nat Commun ; 13(1): 7594, 2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36494367

RESUMO

Sample return missions have provided the basis for understanding the thermochemical evolution of the Moon. Mare basalt sources are likely to have originated from partial melting of lunar magma ocean cumulates after solidification from an initially molten state. Some of the Apollo mare basalts show evidence for the presence in their source of a late-stage radiogenic heat-producing incompatible element-rich layer, known for its enrichment in potassium, rare-earth elements, and phosphorus (KREEP). Here we show the most depleted lunar meteorite, Asuka-881757, and associated mare basalts, represent ancient (~3.9 Ga) partial melts of KREEP-free Fe-rich mantle. Petrological modeling demonstrates that these basalts were generated at lower temperatures and shallower depths than typical Apollo mare basalts. Calculated mantle potential temperatures of these rocks suggest a relatively cooler mantle source and lower surface heat flow than those associated with later-erupted mare basalts, suggesting a fundamental shift in melting regime in the Moon from ~3.9 to ~3.3 Ga.


Assuntos
Meteoroides , Lua , Animais , Feminino , Cavalos , Silicatos , Estro
5.
Int J Mol Sci ; 23(24)2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36555114

RESUMO

Foam concrete is widely used for its excellent properties, such as light weight, heat insulation, fire resistance, and sound insulation. The stability of foam is the main factor that affects the mechanical performance of foam concrete. The experiments are designed from two perspectives: the foam's stability performance and the foam concrete's modification effect. The effects on foam volume, foam half-life, foam bleeding rate, and foam pore size were investigated based on different concentrations of foam stabilizer CMC (0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%). A combination of macroscopic testing and microscopic analysis, a comparative study of dry density, water absorption test, mechanical property test, and pore structure analysis were conducted after using the modified foam for foam concrete. It is shown that the addition of CMC has an enhanced effect on foam stability. Foaming volume, water secretion rate, and average pore size showed a decreasing trend with the increase of CMC admixture, while the foam half-life displayed an increasing trend. In addition, adding CMC reduces the dry density and improves water absorption and compressive strength. The pore structure development of foam concrete has a noticeable improvement effect, and the optimal amount of admixture is 0.4%. Research results provide a reference for applying thickening foam stabilizer CMC in foam concrete.


Assuntos
Carboximetilcelulose Sódica , Estro , Animais , Força Compressiva , Excipientes , Água
6.
Int J Mol Sci ; 23(24)2022 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-36555563

RESUMO

In this work, exfoliated α-zirconium phosphate (α-ZrP) and phosphated cellulose (PCF) were employed to synthesize poly(vinyl alcohol) composite aerogels (PVA/PCF/α-ZrP) with excellent flame retardancy through the multi-directional freezing method. The peak heat release rate (PHRR), total smoke release (TSR), and CO production (COP) of the (PVA/PCF10/α-ZrP10-3) composite aerogel were considerably decreased by 42.3%, 41.4%, and 34.7%, as compared to the pure PVA aerogel, respectively. Simultaneously, the limiting oxygen index (LOI) value was improved from 18.1% to 28.4%. The mechanistic study of flame retardancy showed evidence that PCF and α-ZrP promoted the crosslinking and carbonization of PVA chains to form a barrier, which not only served as insulation between the material and the air, but also significantly reduced the emissions of combustible toxic gases (CO2, CO). In addition, the multi-directional freezing method further improved the catalytic carbonization process. This mutually advantageous strategy offers a new strategy for the preparation of composite aerogels with enhanced fire resistance.


Assuntos
Retardadores de Chama , Álcool de Polivinil , Animais , Congelamento , Catálise , Celulose , Estro
7.
Sci Rep ; 12(1): 21812, 2022 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-36528650

RESUMO

In the pump of different machines, the vacuum pump oil (VPO) is used as a lubricant. The heat rate transport mechanism is a significant requirement for all industries and engineering. The applications of VPO in discrete fields of industries and engineering fields are uranium enrichment, electron microscopy, radio pharmacy, ophthalmic coating, radiosurgery, production of most types of electric lamps, mass spectrometers, freeze-drying, and, etc. Therefore, in the present study, the nanoparticles are mixed up into the VPO base liquid for the augmentation of energy transportation. Further, the MHD flow of a couple stress nanoliquid with the applications of Hall current toward the rotating disk is discussed. The Darcy-Forchheimer along with porous medium is examined. The prevalence of viscous dissipation, thermal radiation, and Joule heating impacts are also considered. With the aid of Cattaneo-Christov heat-mass flux theory, the mechanism for energy and mass transport is deliberated. The idea of the motile gyrotactic microorganisms is incorporated. The existing problem is expressed as higher-order PDEs, which are then transformed into higher-order ODEs by employing the appropriate similarity transformations. For the analytical simulation of the modeled system of equations, the HAM scheme is utilized. The behavior of the flow profiles of the nanoliquid against various flow parameters has discoursed through the graphs. The outcomes from this analysis determined that the increment in a couple-stress liquid parameter reduced the fluid velocity. It is obtained that, the expansion in thermal and solutal relaxation time parameters decayed the nanofluid temperature and concentration. Further, it is examined that a higher magnetic field amplified the skin friction coefficients of the nanoliquid. Heat transport is increased through the rising of the radiation parameter.


Assuntos
Estro , Farmácia , Animais , Temperatura Alta , Indústrias , Simulação por Computador
8.
BMC Vet Res ; 18(1): 414, 2022 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36414934

RESUMO

BACKGROUND: Progesterone plays a crucial role in the maintenance of pregnancy from conception to about 100-120 days of gestation when placenta becomes the main source of gestagens. The aim of the study was to test progesterone concentration 14 days after ovulation in pregnant mares and relate it to peak estral endometrial edema and the presence of intrauterine fluid (IUF) after artificial insemination (AI), the number of treatments against IUF, and the time from AI to the day when the uterus was found free of fluid. RESULTS: Mares were divided into two groups: group A (n = 13; age 10.8 ± 4.5 years) in which a normal embryonic vesicle with a diameter ≥ 14 mm and a corpus luteum with a diameter ≥ 15 mm were found 14 days after ovulation, and group B (n = 22; age 9.4 ± 4 .0 years) in which 14 days after ovulation, a small (< 15 mm) corpus luteum and/or a small embryonic vesicle was observed (diameter < 14 mm). Mares from group A had a significantly higher progesterone concentrations at 14 days after ovulation compared with group B mares. The presence of IUF, the number of treatments against IUF, and the time from AI to the day when uterus was found free of fluid did not affect progesterone concentration measured 14 days after ovulation. In group B, a significant correlation was found between progesterone concentration measured 14 days after ovulation and endometrial edema evaluated during estrus. CONCLUSIONS: In some cases poor development of endometrial edema during estrus can be associated with lower progesterone production 14 days after ovulation. Nevertheless, scientific explanation for this finding cannot be given based on our study.


Assuntos
Estro , Progesterona , Gravidez , Cavalos , Feminino , Animais , Ovulação , Inseminação Artificial/veterinária , Edema/veterinária
9.
Anim Sci J ; 93(1): e13782, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36345759

RESUMO

ß-Carotene is an essential nutrient in cattle reproduction. The objective of this study was to evaluate the effect of ß-carotene supplementation on ovarian activities throughout the estrous cycle in nonpregnant Japanese Black cows. The estrous cycles of eight nonpregnant Japanese Black cows were synchronized using a double synch protocol, and the cows were divided into two groups. The cows in the ß-carotene (BC) group received supplementation with 1000 mg/day ß-carotene for 46 days including the synchronization period. The cows in the control (C) group did not receive ß-carotene supplementation. The results showed that ß-carotene supplementation at 1000 mg/day was sufficient to maintain a high plasma ß-carotene concentration and increase the plasma retinol concentration and that ß-carotene supplementation had no significant effects on the dominant follicle diameter, total number of estrus behaviors, or length of the estrous cycle. In contrast, the areas under the P4 concentration curves in the BC group were higher than those obtained for the C group. In conclusion, a high plasma ß-carotene concentration in Japanese Black cows promotes P4 production in the luteal phase of the estrous cycle and total P4 production throughout the estrous cycle without changing the length of the estrous cycle.


Assuntos
Progesterona , beta Caroteno , Feminino , Bovinos , Animais , beta Caroteno/farmacologia , Ciclo Estral , Folículo Ovariano , Estro , Sincronização do Estro/métodos
10.
Sci Rep ; 12(1): 17685, 2022 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-36271290

RESUMO

The rodent estrous cycle modulates a range of biological functions, from gene expression to behavior. The cycle is typically divided into four stages, each characterized by distinct hormone concentration profiles. Given the difficulty of repeatedly sampling plasma steroid hormones from rodents, the primary method for classifying estrous stage is by identifying vaginal epithelial cell types. However, manual classification of epithelial cell samples is time-intensive and variable, even amongst expert investigators. Here, we use a deep learning approach to achieve classification accuracy at expert level. Due to the heterogeneity and breadth of our input dataset, our deep learning approach ("EstrousNet") is highly generalizable across rodent species, stains, and subjects. The EstrousNet algorithm exploits the temporal dimension of the hormonal cycle by fitting classifications to an archetypal cycle, highlighting possible misclassifications and flagging anestrus phases (e.g., pseudopregnancy). EstrousNet allows for rapid estrous cycle staging, improving the ability of investigators to consider endocrine state in their rodent studies.


Assuntos
Aprendizado Profundo , Roedores , Feminino , Animais , Estro , Ciclo Estral/metabolismo , Hormônios
11.
Theriogenology ; 194: 162-170, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36265337

RESUMO

The aim of the present study was to evaluate the vascularization features of canine ovaries during the follicular phase and the formation of the corpora lutea by using Doppler ultrasonography and Contrast-Enhanced Ultrasound (CEUS). Eight healthy bitches were enrolled in the study and were evaluated at five different timepoints (T1 - T5) of the estrous cycle established by vaginal cytology and serum progesterone concentration. Ultrasonographic examinations were performed by a single operator using the ACUSON S2000/SIEMENS machine equipped with a linear multifrequency transducer (9.0 MHz). Color-coded Doppler evaluation of the ovarian parenchyma was performed to investigate the aspects of the signal detection throughout the different timepoints. Pulsed-wave Doppler of the intraovarian arteries was performed to evaluate spectral waveform and doppler velocimetric parameters of Systolic Peak Velocity (SPV cm/s), End Diastolic Velocity (EDV cm/s), Resistivity Index (RI) and Pulsatility Index (PI). CEUS evaluation of the ovaries was performed using a vascular contrast agent (SonoVue®, Bracco, Sao Paulo, Brazil) and the CADENCE™ Contrast Pulse Sequencing (CPS, Siemens) software, in order to perform both qualitative and quantitative analysis. Perfusion parameters of pixel number, peak intensity (PPI in %), time to peak intensity (TTP in s), mean transit time (MTT in s) and area under the curve (AUC in %). Colour-coded Doppler evaluation demonstrated an increase in signal detection as cycle progressed, with blood flow initially detected with few coloured pixels and mainly at the ventral surface of the ovaries. Further on, the number of coloured pixels increased and spreading to the central region, resulting in a circular-like pattern around the corpora hemorrhagica. The spectral waveform was consistent at all timepoints. SPV (cm/s) and EDV (cm/s) presented a numeric trend and a slight statistical difference at all timepoints, whereas no difference was found for RI and PI. CEUS evaluation demonstrated an increase in pixel intensity across all the timepoints. Quantitative CEUS analysis revealed a statistical difference in PPI (%), MTT (s) and AUC (%) at T5. CEUS evaluation of the ovaries was feasible and demonstrated a marked increase in perfusion parameters in the late postovulatory period, demonstrating its applicability in the assessment of canine corpora lutea development.


Assuntos
Ovário , Ultrassonografia Doppler , Feminino , Cães , Animais , Ovário/diagnóstico por imagem , Ovário/irrigação sanguínea , Brasil , Ultrassonografia/métodos , Ultrassonografia Doppler/veterinária , Corpo Lúteo/diagnóstico por imagem , Estro , Ultrassonografia Doppler em Cores
12.
Res Vet Sci ; 152: 579-581, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36201904

RESUMO

Leptospirosis in ruminants presents as a chronic disease that causes several reproductive disorders leading to severe economic losses. The current recommended treatment can be efficient to eliminate the renal carrier state, however little is known about the effect of this drug in removing the genital carrier state and the hormonal influence on it. A total of 12 primiparous sheep experimentally infected with a strain of Leptospira santarosai serogroup Sejroe, FV52 strain, were used and distributed as group A (estrus; n = 5), group B (metaestrus; n = 4) and group C (control; n = 3). At D0, groups A and B were treated with streptomycin (25 mg/kg) single dose. Samples of cervicovaginal mucus (CVM) were collected on days 0, 3, and 35 post-treatment, while uterine fragment (UF) samples were collected on days 3 and 35, for PCR. Even after antibiotic treatment, all groups presented infected animals, at D3 and D35, with no significant difference between the treated and control groups. Based on these results, it was conducted a second protocol of treatment with streptomycin, IM (25 mg/kg) for three consecutive days, which was 100% effective to eliminate the genital carrier state; therefore, that protocol should be recommended.


Assuntos
Leptospira , Leptospirose , Doenças dos Ovinos , Feminino , Ovinos , Animais , Estreptomicina/uso terapêutico , Leptospirose/tratamento farmacológico , Leptospirose/veterinária , Sorogrupo , Estro , Útero , Doenças dos Ovinos/tratamento farmacológico
13.
Endocrine ; 78(3): 476-483, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36301508

RESUMO

PURPOSE: Our previous study showed that 6-h fasting increased insulin expression in the hypothalamus of male rats. We, therefore, wanted to examine if this phenomenon occurs in female rats and whether it depended on the estrus cycle phase. METHODS: Female rats in proestrus or diestrus were either exposed to 6-h fasting or had ad libitum access to food. The serum, cerebrospinal fluid, and hypothalamic insulin levels were determined using radioimmunoassay. The hypothalamic insulin mRNA expression was measured by RT-qPCR, while the hypothalamic insulin distribution was assessed immunohistochemically. RESULTS: Albeit the short-term fasting lowered circulating insulin, both hypothalamic insulin mRNA expression and hypothalamic insulin content remained unaltered. As for the hypothalamic insulin distribution, strong insulin immunopositivity was noted primarily in ependymal cells lining the upper part of the third ventricle and some neurons mainly located within the periventricular nucleus. The pattern of insulin distribution was similar between the controls and the females exposed to fasting regardless of the estrous cycle phase. CONCLUSION: The findings of this study indicate that the control of insulin expression in the hypothalamus differs from that in the pancreatic beta cells during short-term fasting. Furthermore, they also imply that the regulation of insulin expression in the female hypothalamus is different from males but independent of the estrus cycle phase.


Assuntos
Jejum , Insulina , Animais , Ratos , Feminino , Masculino , Insulina/metabolismo , Hipotálamo/metabolismo , Estro/fisiologia , RNA Mensageiro/metabolismo
14.
J Dairy Sci ; 105(10): 8523-8534, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36055839

RESUMO

The objectives of this retrospective observational study were to determine the associations of anogenital distance (AGD) with (a) postpartum estrous activity, (b) diameter of the preovulatory follicle, (c) intensity of estrous expression, (d) postestrus ovulation, (e) corpus luteum (CL) size, and (f) concentrations of progesterone at estrus and on d 7 after estrus. Lactating Holstein cows (n = 178; 55 primiparous, 123 multiparous) were enrolled into the study during the first postpartum week. All cows were continuously monitored by a pedometer-based automated activity monitoring (AAM) system for estrus. Postpartum estrous activity was assessed using the AAM estrus alerts, in which cows with at least one true estrus alert (i.e., a relative increase in steps from each cow's baseline detected by the AAM and the presence of at least one follicle >15 mm, a CL <20 mm, or no CL detected by ultrasound) by the first 50 d in milk (DIM) were considered to have commenced estrous activity. At the estrus alert >60 DIM, ovulation was determined by ultrasound at 24 h, 48 h, and 7 d after estrus, and blood samples were collected at estrus alert and on d 7 after estrus for progesterone analysis. The AGD was measured from the center of the anus to the base of the clitoris and classified as either short- or long-AGD using 2 cut-points of 148 mm (predictive of the probability of pregnancy to first insemination; short-AGD, n = 115; long-AGD, n = 63) and 142 mm (the median AGD; short-AGD, n = 90; long-AGD, n = 88). Regardless of the cut-point used, early postpartum estrous activity by 50 DIM (67 vs. 54%), duration of estrus (11.6 vs. 9.7 h), and preovulatory follicle diameter (20 vs. 19 mm) were greater in short-AGD than in long-AGD cows. Increased peak of activity at estrus in short-AGD cows (354 vs. 258% mean relative increase) was affected by an interaction between AGD and parity in which multiparous long-AGD cows had lesser relative increase in activity than primiparous cows (217 vs. 386%, respectively). Mean progesterone concentration at estrus was lesser in short-AGD (0.47 vs. 0.61 ng/mL) than in long-AGD cows. The ovulatory response at 24 h did not differ, but at 48 h (91 vs. 78%) and on d 7 after estrus (97 vs. 84%) it was greater in short-AGD cows. Although CL diameter on d 7 after estrus did not differ, short-AGD cows had greater progesterone concentration 7 d after estrus than long-AGD cows (4.1 vs. 3.2 ng/mL, respectively). In conclusion, greater proportions of short-AGD cows commenced estrous activity by 50 DIM, had larger preovulatory follicles, exhibited greater duration of estrus, had reduced progesterone concentration at estrus, had greater ovulation rates and progesterone concentration 7 d after estrus compared with long-AGD cows, with no difference in CL size between AGD groups. Because all the differences in physiological characteristics of short-AGD cows reported herein favor improved reproductive outcomes, we infer that these are factors contributing to improved fertility reported in short-AGD cows compared with long-AGD cows.


Assuntos
Sincronização do Estro , Progesterona , Animais , Bovinos , Estro/fisiologia , Sincronização do Estro/fisiologia , Feminino , Inseminação Artificial/veterinária , Lactação/fisiologia , Ovulação/fisiologia , Período Pós-Parto , Gravidez
15.
J Reprod Dev ; 68(5): 324-329, 2022 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-35922914

RESUMO

Insulin-like peptide 3 (INSL3) and sex steroids were measured in bovine dominant follicles and corpora lutea during the estrus cycle and in follicular cysts. Paired ovaries from beef heifers (n = 47) were classified, by their morphological features, either into four stages of the estrus cycle (Day 1 = day of ovulation, Day 20 = day of estrus) as Stage I (Days 1-4; n = 8), Stage II (Days 5-10; n = 10), Stage III (Days 11-17; n = 8), and Stage IV (Days 18-20; n = 11) or follicular cystic (n = 10). Cysts (n = 15) were subdivided into estrogen-active (n = 7) and estrogen-inactive (n = 8) cysts. INSL3, testosterone, and estradiol-17ß concentrations in the dominant follicular fluid of Stage IV were higher than those in Stages II and III (P < 0.05). INSL3 concentrations in the cystic fluid were similar to those in dominant follicles at Stage IV, whereas testosterone and estradiol-17ß concentrations were lower in cysts (P < 0.05). INSL3 content per estrogen-inactive cyst was higher than that of Stage IV (P < 0.05). INSL3 and progesterone concentrations in luteal tissue and contents per corpus luteum were higher in Stages II and III (P < 0.05). In conclusion, INSL3 secretion in bovine dominant follicles increased with maturation. Follicular cysts may retain the production of INSL3 during their formation but tend to lose the capacity for testosterone secretion. Estrogen-inactive cysts subjected to advanced atresia may accumulate more INSL3. INSL3 production in bovine corpora lutea is enhanced during maturation.


Assuntos
Cisto Folicular , Insulinas , Animais , Bovinos , Corpo Lúteo , Estradiol , Estrogênios , Estro , Feminino , Hormônios Esteroides Gonadais , Folículo Ovariano/química , Peptídeos , Progesterona , Testosterona
16.
Anim Reprod Sci ; 244: 107045, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35932512

RESUMO

Nutritional changes immediately after insemination cause increased embryonic mortality, but the mechanisms controlling this are not well known. Our objective was to evaluate the impact of nutritional change on estrus expression, steroid concentrations, peripheral and uterine luminal fluid metabolites, and embryo quality in beef heifers. Heifers (n = 139) were assigned to one of two pre-artificial insemination (AI) dietary treatments: LOW (≤ 90% NEm) or HIGH (≥ 139% NEm). Heifers were on treatment for 33-36 days before AI (d0) when half of the heifers in each treatment were randomly reassigned to generate four treatments; HIGH-HIGH, HIGH-LOW, LOW-HIGH, and LOW-LOW. Heifers remained on treatments until embryo collection (d 6-8). Negative energy balance was achieved among LOW heifers as demonstrated by body weight loss and increased NEFA concentrations (P < 0.05). Pre-AI treatment influenced expression of estrus (P = 0.05; HIGH 80.4 ± 4.0% vs. LOW 69.4 ± 4.2%). Estradiol concentrations and interval to estrus were not affected by treatment (P > 0.55); however, progesterone concentrations were reduced among LOW compared to HIGH (3.57 ± 0.27, 4.64 ± 0.26 ng/mL, respectively; P = 0.004), and heifers maintained on the HIGH pre-AI diet had consistently greater concentrations of progesterone from d 0 to d 8 (P = 0.014). Pre-AI treatment influenced embryo stage (P = 0.05; HIGH 3.61 ± 0.32 vs. LOW 2.72 ± 0.30). Post-AI treatment affected embryo grade (P = 0.02; HIGH 1.78 ± 0.23 vs. LOW 2.64 ± 0.27). In summary, pre-AI nutrient restriction caused decreased expression of estrus, reduced progesterone concentrations after AI, and negatively impacted embryo development, while post-AI restriction hindered embryo quality.


Assuntos
Sincronização do Estro , Progesterona , Animais , Bovinos , Dinoprosta , Desenvolvimento Embrionário , Estro , Feminino , Hormônio Liberador de Gonadotropina , Inseminação Artificial/veterinária , Nutrientes
17.
Reprod Fertil Dev ; 34(14): 920-932, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35969892

RESUMO

CONTEXT: Most of our current knowledge regarding echidna reproductive behaviour is based on qualitative measurements; therefore, it is unclear if specific behavioural cues could be utilised in their captive reproductive management. AIMS: This study aimed to identify quantitative changes in general and reproductive behaviour of echidna breeding pairs and pregnant females that might facilitate the detection of oestrus and impending oviposition and provide a summary of reproductive behaviour observed in a captive colony over a three-year observation period. METHODS: Three echidna breeding pairs and two trios were monitored daily for seven reproductive and eight general behaviours during the 2020 breeding season. After confirmed copulation, females were monitored for four egg-laying and eight general behaviours until egg incubation. General observations of reproductive behaviours during the 2018-2020 breeding seasons were recorded as part of routine husbandry. KEY RESULTS: For breeding pairs, there was a significant rate of change over time before and after copulation for the behaviours 'urogenital sniffing', 'rolling' and 'copulation attempt'. For pregnant females, time engaged in 'pacing' significantly increased while 'time eating' and the 'quantity of food eaten' significantly decreased on the day of oviposition. We were not able to identify oestrus from specific behaviours, but our observations suggest that the female echidna's period of receptivity is less than 24h. CONCLUSIONS: The frequency that males express 'urogenital sniffing', 'rolling' and 'copulation attempt' toward the female can be used to alert zookeepers that copulation has likely occurred. Increased pacing, reduced feeding time and quantity of food eaten can aid zookeepers to identify impending oviposition. IMPLICATIONS: This study demonstrates that there are quantifiable changes in specific echidna behaviours that can be incorporated into zoo husbandry practices to improve the reproductive management of this species.


Assuntos
Comportamento Reprodutivo , Tachyglossidae , Animais , Estro , Feminino , Masculino , Oviposição , Gravidez , Reprodução
18.
Reprod Domest Anim ; 57(11): 1428-1439, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35924392

RESUMO

The aim of the first study was to determine the influence of the calf handling (restricted or full contact) and fenceline bull stimulation on performance of mothers and their calves. The aim of the second study was to determine the relative impact of calf-bull contact, comparing the result of restricted calf and no bull with that of fenceline calf contact and direct bull contact on the performance of mother buffaloes and their calves. In Experiment 1, 24 mother-calf dyads were allocated to three treatments: NCB (no calf-mother-bull contact), RC-FBC (restricted calf and fenceline bull contact) and FC-FBC (fenceline calf and fenceline bull contact). In Experiment 2, another 24 mother-calf dyads were allocated to two treatments: RC-NB (restricted calf and no bull contact) and FC-DBC (fenceline calf and direct bull contact). In Experiment 1, average daily gain (ADG) was greater in FC-FBC than RC-FBC and NCB calves (p < .05). Average dry matter intake (DMI) was greater in FC-FBC than RC-FBC and NCB calves. DMI of buffaloes was greater in FC-FBC than RC-FBC and NCB. Daily milk yield of buffaloes was more (p < .05) in FC-FBC (10.2 ± 0.2 kg) than RC-FBC (8.4 ± 0.2 kg) and RC-FBC (7.8 ± 0.2 kg). There were no statistical differences observed in the interval from calving to first oestrus, first service, service period among three groups. In Experiment 2, ADG's and DMI were greater in FC-FBC calves than RC-FBC (p < .05). DMI of buffaloes was greater in FC-DBC than RC-NBC (p < .05). Daily milk yield of buffaloes was greater (p < .05) in FC-DBC (11.6 ± 0.2 kg) than RC-NBC (8.3 ± 0.2 kg). The first oestrus (51.5 ± 3.1 vs. 103.2 ± 7.2), days to first service (74.8 ± 3.5 vs.112.0 ± 7.6) and service period (78.8 ± 4.8 vs.118.9 ± 8.3 days) were lower (p < .05) in FC-DBC than RC-NBC buffaloes. The fenceline calf-mother contact increased the growth rate, FCR, and feeding efficiency of buffalo calves; reduced some stress responses and improved the productive performance of buffalo mothers. Further, mother-bull contact stimulated the post-partum reproductive performance of buffaloes in fenceline calf contact.


Assuntos
Bison , Búfalos , Feminino , Bovinos , Animais , Humanos , Búfalos/fisiologia , Mães , Reprodução , Estro/fisiologia , Leite , Ração Animal , Dieta/veterinária , Desmame
19.
J Dairy Sci ; 105(10): 8411-8425, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36028340

RESUMO

The primary objective of this randomized controlled experiment was to evaluate the insemination dynamic and reproductive performance of cows managed with a targeted reproductive management (TRM) program designed to prioritize artificial insemination (AI) at detected estrus (AIE) and optimize timing of AI by grouping cows based on detection of estrus during the voluntary waiting period (VWP). Our secondary objective was to evaluate reproductive outcomes for cows with or without estrus during the VWP. Lactating Holstein cows fitted with an ear-attached sensor for detection of estrus were randomly assigned to a TRM treatment that prioritized AIE based on detection of estrus during the VWP (TP-AIE; n = 488), a non-TRM treatment that prioritized AIE (P-AIE; n = 489), or an all timed AI (TAI) treatment with extended VWP (ALL-TAI; n = 491). In TP-AIE, cows with or without automated estrus alerts (AEA) recorded during the VWP received AIE if detected in estrus for at least 31 ± 3 or 17 ± 3 d after a 49 d VWP, respectively. Cows not AIE with or without AEA during the VWP received TAI after Ovsynch with progesterone supplementation and 2 PGF2α treatments (P4-Ov) at 90 ± 3 or 74 ± 3 d in milk (DIM), respectively. In P-AIE, cows received AIE if detected in estrus for 24 ± 3 d after a 49 d VWP, and if not AIE received TAI at 83 ± 3 DIM after P4-Ov. In ALL-TAI, cows received TAI at 83 ± 3 DIM after a Double-Ovsynch protocol. Data were analyzed by logistic and Cox's proportional hazard regression. The proportion of cows AIE did not differ for TP-AIE (71.0%) and P-AIE (74.6%). Overall P/AI at 39 d after first service was greater for the ALL-TAI (47.6%) than for the P-AIE (40.2%) and TP-AIE (39.5%) treatments. The hazard of pregnancy up to 150 DIM was greater for cows in TP-AIE (hazard ratio = 1.2; 95% confidence interval: 1.1-1.4) and P-AIE (hazard ratio = 1.2; 95% confidence interval: 1.1-1.4) than for cows in the ALL-TAI treatment which resulted in median time to pregnancy of 89, 89, and 107 d. Conversely, the proportion of cows pregnant at 150 DIM did not differ (ALL-TAI 78.5%, P-AIE 76.3%, TP-AIE 76.0%). Except for a few outcomes for which no difference was observed, cows detected in estrus during the VWP had better performance than cows not detected in estrus. Cows with AEA during the VWP were more likely to receive AIE, had greater P/AI, and greater pregnancy rate up to 150 DIM regardless of first service management. We conclude that a TRM program designed to prioritize AIE by grouping cows based on detection of estrus during the VWP was an effective strategy to submit cows for first service resulting in similar or improved performance than a non-TRM program that prioritized AIE or an all-TAI program with extended VWP. Also, AEA recorded during the VWP might be used as a strategy for identifying subgroups of cows with different reproductive performance.


Assuntos
Detecção do Estro , Sincronização do Estro , Animais , Bovinos , Dinoprosta , Estro , Detecção do Estro/métodos , Sincronização do Estro/métodos , Feminino , Hormônio Liberador de Gonadotropina , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Lactação , Gravidez , Progesterona , Prostaglandinas F
20.
Theriogenology ; 192: 45-51, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36044806

RESUMO

The present study was performed to evaluate the reproductive performance of gilts inseminated using fixed-time artificial insemination (FTAI) protocol. A total of 408 Landrace × Yorkshire crossbred gilts were included in the experiment. Gilts at 8 months of age were randomly allocated into three groups: control AI (n = 192), treatment 1-TAI (n = 117) and treatment 2-FTAI (n = 99). Gilts in the control AI group were inseminated 2-3 times during standing oestrus at 0, 12 and 24 h after the onset of oestrus. Gilts in the treatment 1-TAI group were orally administered 20 mg per day of altrenogest for 18 days and then inseminated 2-3 times during standing oestrus by conventional AI. Gilts in the treatment 2-FTAI group were synchronized like gilts in treatment 1-TAI group but then GnRH (10 µg of buserelin) was administered 120 h after the end of altrenogest treatment and fixed time artificial inseminated twice at 24 and 32 h after GnRH irrespective of the presence of oestrus or not. Conception rate of gilts in treatment 2-FTAI (87.9%) was similar to the treatment 1-TAI (94.9%) and control AI (83.3%) (P > 0.05). Conception rate in treatment 1-TAI (94.9%) was higher compared to control AI group (83.3%, P = 0.040). Farrowing rate of gilts in treatment 2-FTAI (83.8%) was similar to treatment 1-TAI (89.7%) and control AI (76.0%) (P > 0.05). Farrowing rate of treatment 1-TAI (89.7%) was higher than control AI gilts (76.0%, P = 0.033). In treatment 2-FTAI, the conception and farrowing rate of the nine gilts that were inseminated even if they were not detected in oestrus (all during warm season) was 44.4% and 44.4%, respectively. Regular return to oestrus was similar between groups (9.4%, 0.9% and 4.1% for control AI, treatment 1-TAI and treatment 2-FTAI, respectively, P > 0.05). The total number of piglets born per litter in treatment 1-TAI group was higher than control AI (13.1 ± 0.2 versus 11.6 ± 0.2, respectively, P < 0.001) and treatment 2-FTAI groups (12.2 ± 0.3, P = 0.019). The number of piglets born alive was higher in treatment 1-TAI (12.1 ± 0.3) compared to treatment 2-FTAI (11.3 ± 0.2) and control AI group (11.2 ± 0.3). The percentage of stillbirth and mummified foetus were not different between groups (P > 0.05). The present study indicated that fixed-time AI in gilts can be successfully performed by administration of altrenogest for 18 days, GnRH at 120 h after altrenogest withdrawal and then double fixed-time AI at 24 and 32 h after the administration of GnRH. Fertility metrics such as conception rate, farrowing rate and litter performances using this method were similar to gilts inseminated at oestrus with conventional AI.


Assuntos
Busserrelina , Inseminação Artificial , Animais , Estro , Sincronização do Estro , Feminino , Hormônio Liberador de Gonadotropina , Inseminação Artificial/métodos , Inseminação Artificial/veterinária , Reprodução , Sus scrofa , Suínos
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