Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 19.303
Filtrar
1.
J Reprod Dev ; 70(1): 25-29, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38171908

RESUMO

The aim of the present study was to develop a semi-quantitative urine pregnancy test for mares based on the Cuboni reaction and to verify the reliability of this test. The urine specimens were hydrolyzed by heating in the presence of hydrochloric acid. The resulting free estrogens were extracted from the urine matrix using toluene. Sulfuric acid was added to the toluene extract and the mixture was heated again. The lower layer in the test tube containing sulfuric acid was used for fluorescence measurements with excitation at 355 nm and measurement at 535 nm. The fluorometric Cuboni test revealed that the fluorescence counts in urine samples collected after the second trimester of gestation were significantly higher than those obtained from barren mares. The levels of estrogens, including equilin, estrone and estardiol-17ß exhibited a dose-dependent increase in fluorescence counts, whereas other steroids, such as progesterone, testosterone, and cortisol, did not affect fluorescence. Heat treatment of urine samples with hydrochloric acid significantly increased the fluorescence counts in those collected after the second trimester of gestation compared to non-pregnant samples, implying the presence of large amounts of conjugated estrogens in pregnant mare urine. Fluorescence counts in urine samples obtained during pregnancy showed a positive relationship with estrone concentrations as measured by enzyme immunoassay. The results of the present study showed that the fluorometric Cuboni test facilitates urine fluorescence counts depending on the urinary estrogen content and is capable of discriminating between pregnancy and non-pregnancy states beyond the second trimester of gestation in mares.


Assuntos
Estrona , Prenhez , Ácidos Sulfúricos , Gravidez , Cavalos , Animais , Feminino , Ácido Clorídrico , Reprodutibilidade dos Testes , Estrogênios , Tolueno
2.
Artigo em Alemão | MEDLINE | ID: mdl-37820617

RESUMO

The administration of drugs to pregnant bitches may not only pose a potential danger to the bitch but also to the fetuses. In this context, the extent of the risk also depends on the stage of gestation. Although a number of agents are known to have a fetotoxic and/or teratogenic potential, insufficient knowledge concerning their potential risk to the embryo/fetus is available for the majority of drugs.Arranged in groups of active substances, a selection of drugs that are assumed to be safe according to the current state of knowledge is provided. Drugs for which there is insufficient knowledge or which are clearly contraindicated are also mentioned.The second part of this overview covers the use of medicines in puppies. The physiology of a puppy does not simply correspond to that of a small dog. Only very few drugs posess valid pharmacological data for use in puppies. However, a subset of restrictions on the use of pharmacologic agents may be derived from the specifics of puppy physiology.The recommendations made do not claim to be complete and no guarantee for accuracy is provided, as these have been compiled from a literature review. In certain cases, the recommendations are even contradictory.Veterinarians are therefore encouraged to report all adverse events associated with treatments of pregnant bitches and puppies within the framework of pharmacovigilance. This is the only way to close gaps in knowledge about the treatment of these special patients.


Assuntos
Preparações Farmacêuticas , Prenhez , Animais , Cães , Feminino , Gravidez
4.
Biol Lett ; 19(6): 20230183, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37376852

RESUMO

In the majority of mammals, gestation length is relatively consistent and seldom varies by more than 3%. In a few species, females can adjust gestation length by delaying the development of the embryo after implantation. Delays in embryonic development allow females to defer the rising energetic costs of gestation when conditions are unfavourable, reducing the risk of embryo loss. Dispersal in mammals that breed cooperatively is a period when food intake is likely to be suppressed and stress levels are likely to be high. Here, we show that pregnant dispersing meerkats (Suricata suricatta), which have been aggressively evicted from their natal group and experience weight loss and extended periods of social stress, prolong their gestation by means of delayed embryonic development. Repeated ultrasound scans of wild, unanaesthetized females throughout their pregnancies showed that pregnancies of dispersers were on average 6.3% longer and more variable in length (52-65 days) than those of residents (54-56 days). The variation in dispersers shows that, unlike most mammals, meerkats can adapt to stress by adjusting their pregnancy length by up to 25%. By doing so, they potentially rearrange the costs of gestation during adverse conditions of dispersal and enhance offspring survival.


Assuntos
Distribuição Animal , Herpestidae , Prenhez , Estresse Psicológico , Animais , Feminino , Gravidez , Prenhez/fisiologia
5.
Mol Reprod Dev ; 90(7): 658-672, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-35385215

RESUMO

Pregnancy establishment in mammals, including pigs, requires coordinated communication between developing conceptuses (embryos with associated membranes) and the maternal organism. Porcine conceptuses signalize their presence by secreting multiple factors, of which estradiol-17ß (E2) is considered the major embryonic signal initiating the maternal recognition of pregnancy. During this time, a limited supply of prostaglandin (PGF2α) to the corpora lutea and an increased secretion of luteoprotective factors (e.g., E2 and prostaglandin E2 [PGE2]) lead to the corpus luteum's maintained function of secreting progesterone, which in turn primes the uterus for implantation. Further, embryo implantation is related to establishing an appropriate proinflammatory environment coordinated by the secretion of proinflammatory mediators including cytokines, growth factors, and lipid mediators of both endometrial and conceptus origin. The novel, dual role of PGF2α has been underlined. Recent studies involving high-throughput technologies and sophisticated experimental models identified a number of novel factors and revealed complex relationships between these factors and those already established. Hence, it seems that early pregnancy should be regarded as a sequence of processes orchestrated by pleiotropic factors that are involved in redundancy and compensatory mechanisms that preserve the essential functions critical for implantation and placenta formation. Therefore, establishing the hierarchy between all molecules present at the embryo-maternal interface is now even more challenging.


Assuntos
Dinoprosta , Prenhez , Gravidez , Feminino , Animais , Suínos , Prenhez/metabolismo , Implantação do Embrião , Prostaglandinas/metabolismo , Dinoprostona , Mamíferos
6.
J Dairy Sci ; 106(2): 822-842, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36460512

RESUMO

Mobilization of body reserves including fat, protein, and glycogen is necessary to overcome phases of negative nutrient balance typical for high-yielding dairy cows during the periparturient period. Skeletal muscle, the largest internal organ in mammals, plays a crucial role in maintaining metabolic homeostasis. However, unlike in liver and adipose tissue, the metabolic and regulatory role of skeletal muscle in the adaptation of dairy cows to the physiological needs of pregnancy and lactation has not been studied extensively. The functional integrity and quality of skeletal muscle are maintained through a constant turnover of protein, resulting from both protein breakdown and protein synthesis. Thus, muscle protein breakdown (MPB) and synthesis are intimately connected and tightly controlled to ensure proper protein homeostasis. Understanding the regulation of MPB, the catabolic component of muscle turnover, and its assessment are therefore important considerations to provide information about the timing and extent of tissue mobilization in periparturient dairy cows. Based on animal models and human studies, it is now evident that MPB occurs via the integration of 3 main systems: autophagy-lysosomal, calpain Ca2+-dependent cysteine proteases, and the ubiquitin-proteasome system. These 3 main systems are interconnected and do not work separately, and the regulation is complex. The ubiquitin-proteasomal system is the most well-known cellular proteolytic system and plays a fundamental role in muscle physiology. Complete degradation of a protein often requires a combination of the systems, depending on the physiological situation. Determination of MPB in dairy cows is technically challenging, resulting in a relative dearth of information. The methods for assessing MPB can be divided into either direct or indirect measurements, both having their strengths and limitations. Available information on the direct measures of MPB primarily comes from stable isotopic tracer methods and those of indirect measurements from assessing expression and activity measures of the components of the 3 MPB systems in muscle biopsy samples. Other indirect approaches (i.e., potential indicators of MPB), including ultrasound imaging and measuring metabolites from muscle degradation (i.e., 3-methylhistidine and creatinine), seem to be applicable methods and can provide useful information about the extent and timing of MPB. This review presents our current understanding, including methodological considerations, of the process of MPB in periparturient dairy cows.


Assuntos
Lactação , Proteínas Musculares , Músculo Esquelético , Período Periparto , Prenhez , Proteólise , Animais , Bovinos , Feminino , Gravidez , Tecido Adiposo/metabolismo , Dieta/veterinária , Lactação/fisiologia , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismo , Período Periparto/metabolismo , Prenhez/metabolismo
8.
J S Afr Vet Assoc ; 93(2)2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36412081

RESUMO

Population demographics and reproductive performance of Thoroughbred populations have been described, but the most recent assessment of the South African Thoroughbred population was reported two decades ago. Objectives of this study were to report demographic data for selected Thoroughbred breeding populations and to analyse selected mare-level variables in association with foaling outcomes, as predictors of reproductive performance. The National Horseracing Authority of Southern Africa's stud health scheme requires annual screening of Thoroughbred stallions, maiden and barren mares for venereal pathogens prior to breeding. In 2018 and 2019, 1 065 and 1 207 horses were sampled, respectively. Demographic data were sourced from laboratory sample submission forms that accompanied samples and supplemented by data gathered from the annual Thoroughbred foal identification programme. Univariate analysis of candidate predictors of successful foaling outcomes was performed followed by assessment in a multivariable model.Median ages of mares and stallions tested in 2018 and 2019 were nine and 11 years, respectively. Nearly twice the number of barren compared to maiden mares were tested in each year, and failure to conceive was the most common reported reason for classification as barren. Of mares tested in 2018 and 2019, 68.1% (95% CI 65.1, 70.9) and 63.3% (95% CI 60.4, 66.1), respectively, subsequently produced foals that were presented for identification. Mare age, rather than reproductive status, was a significant predictor of having a foal presented for identification. In conclusion, novel demographic data were described for South African Thoroughbred populations. Seasonal foaling rate as the selected measure of reproductive performance for sampled mares ranged from 63.3% to 68.1% and declined with increasing mare age.


Assuntos
Prenhez , Gravidez , Cavalos , Animais , Feminino , Masculino , África do Sul/epidemiologia , Reprodução
9.
Anim Reprod Sci ; 247: 107149, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36375290

RESUMO

While detrimental effects of reduced plasma progesterone concentration in the early luteal phase on conceptus development in horses have recently been demonstrated, there is no information on associated effects on the endometrium, allantochorion (AC), and chorionic girdle (CG) in this species. We hypothesised that reduced early postovulatory progesterone concentration in pregnant horses is detrimental to endometrial function and development of the embryonic membranes and is an underlying cause of delayed conceptus development. After insemination and ovulation, mares (n = 11) were assigned to treatment (TREAT) or control (CON) during two pregnancies. In TREAT pregnancies, mares received a PGF2α analogue for four consecutive days starting on the day of ovulation with the aim to reduce progesterone secretion. Mares were left untreated in CON pregnancies and thus served as their own controls. Endometrial biopsies for analysis of histomorphology, epidermal growth factor (EGF) and EGF receptor (EGFR) mRNA and protein expression in the endometrium, AC, and CG as well as abundance of regulatory T lymphocytes (Tregs) were collected on day 34 of pregnancy. Histomorphometric analysis revealed a higher luminal endometrium and a higher CG epithelium in CON compared to TREAT pregnancies. Abundance of mRNA for EGF and EGFR was large in the endometrium, AC and CG but did not differ between TREAT and CON pregnancies. The number of endometrial regulatory T lymphocytes was reduced in TREAT compared to CON pregnancies, adding further aspects to the potentially detrimental effects of reduced progesterone concentrations on equine pregnancy.


Assuntos
Prenhez , Progesterona , Gravidez , Cavalos/genética , Animais , Feminino , Progesterona/farmacologia , Fase Luteal , Placentação , Fator de Crescimento Epidérmico/genética , Endométrio/metabolismo , RNA Mensageiro/metabolismo , Receptores ErbB/metabolismo , Receptores ErbB/farmacologia
10.
Theriogenology ; 194: 58-63, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36209545

RESUMO

Canine gestational age can be estimated based on fetal kidney length (L) although accuracy, sensitivity and specificity decrease during the last 5 days of pregnancy. In humans, fetal renal cortical and medullary thickness (CT and MT) and their ratio (CT/MT) are described as useful tools for monitoring the development of fetal kidneys. The aim of this study was to evaluate a potential relationship between canine fetal kidney parameters and gestational age. Ten clinically healthy pregnant bitches of different breeds were monitored by ultrasound at least twice from -10 to 0 days before parturition (dbp). L, CT, MT and CT/MT were measured on the three most caudal fetuses of both uterine horns. Statistical analysis was performed using a linear mixed model considering maternal size (small ≤10 kg, N = 4, medium 11-25 kg, N = 3, and large 26-40 kg, N = 3) as fixed effect, dbp (-10 to 0) and litter size as covariates, and the bitch as a random and repeated effect. Dbp and L, CT, MT showed a negative and linear correlation, and their estimated regression coefficients were -0.68 ± 0.14, -0.04 ± 0.01 and -0.12 ± 0.02 mm, respectively (P < 0.01). CT/MT decreased as parturition approached, whereas MT and CT increased. A statistically significant difference was found for L between small and large bitches (17 ± 1 vs 24 ± 2 mm, P = 0.03) and, for CT, between small, medium and large bitches (1.57 ± 0.04 vs 1.77 ± 0.04 vs 1.99 ± 0.05 mm, P < 0.001). None of the renal parameters were affected by litter size. L, CT, MT and CT/MT are related to dbp and may be considered for predicting parturition in dogs.


Assuntos
Prenhez , Gravidez , Feminino , Humanos , Cães , Animais , Ultrassonografia Pré-Natal/veterinária , Parto , Feto , Rim/diagnóstico por imagem
11.
Reprod Fertil Dev ; 34(16): 1023-1033, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36116787

RESUMO

CONTEXT: The establishment of pregnancy in cows requires uterine activity regulation of the main Hippo signalling effector yes-associated protein 1 (YAP). It remains unknown (1) how YAP activity at the corpus luteum (CL) correlates with early pregnancy-related events in ruminants; and (2) if YAP activity in the uterus and CL can be affected by metabolic disorders that may lead to pregnancy failure in ruminants. AIMS AND METHODS: To determine the effect of early pregnancy on total and phospho-YAP expression and its transcriptional activity in the CL, we compared non-pregnant vs pregnant ewes. To understand the YAP activity dysregulation with disorders that may result in pregnancy loss, we induced negative energy balance in pregnant ewes. KEY RESULTS AND CONCLUSIONS: Our main results indicate that early pregnancy alters the expression and activity patterns of YAP in the ovine CL but not in the endometrium. In addition, while our NEB-induced model fails to alter YAP activity at the endometrium level, we found that fasting during the first but not second week of pregnancy affects YAP activity in the CL of pregnant ewes. IMPLICATIONS: The data presented herein provide considerable insight into the activity of a signalling pathway that may be a key player in pregnancy recognition and establishment in ewes.


Assuntos
Prenhez , Proteínas de Sinalização YAP , Animais , Bovinos , Corpo Lúteo/metabolismo , Endométrio/metabolismo , Feminino , Gravidez , Ovinos , Útero/metabolismo
12.
J Equine Vet Sci ; 118: 104104, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35964852

RESUMO

The study aimed to (1) describe the use of reproductive therapeutics; (2) estimate the incidence of disease and injury; and (3) describe non-reproductive medications administered during pregnancy in Thoroughbred broodmares. A prospective birth cohort was established on seven farms across the UK and Ireland. Details of dams' signalment, breeding history, reproductive management during the breeding season(s) and veterinary-attended episodes of illness or injury and medication usage during gestation were retrieved retrospectively for 275 pregnancies in 235 mares over two breeding seasons. Results are reported at pregnancy-level of mares with data available. Preoestrus medications, ovulatory agents and post-covering treatments were administered to 55% (n = 85/155, 95% Confidence interval (CI) 47-62), 64% (n = 101/157, 95% CI 57-71) and 73% (n = 109/150, 95% CI 65-79) of mares respectively. Antibiotics were utilized in 69% (n = 75/109, 95% CI 60-77) of post-covering treatments. Of mares with no visible fluid on post-covering ultrasound, 37% (n = 24/65, 95% CI 26-49) still received treatment. Thirty-four percent (n = 70/203, 95% CI 28-41) of mares suffered at least one veterinary-attended episode of disease or injury, with conditions affecting the musculoskeletal system (23%, n = 46/203, 95%CI 17-29) and placentitis (5%, n = 10/203, 95% CI 3-9) most prevalent. Forty-seven percent (n = 95/203, 95% CI 40-54) of mares received at least one non-reproductive medication during gestation, antibiotics (25%, n = 51/203, 95% CI 20-31) and non-steroidal anti-inflammatory drugs (23%, n = 47/203, 95% CI 18-29) being most frequently prescribed. Post-covering treatments often included antibiotics and were sometimes given in the absence of fluid, highlighting a need to further understand therapeutic rationale. Disease occurrence and medication usage during gestation were frequent and warrant additional investigation.


Assuntos
Prenhez , Gravidez , Cavalos , Animais , Feminino , Estudos Prospectivos , Estudos Retrospectivos , Reprodução , Antibacterianos/efeitos adversos
13.
Cytokine ; 157: 155966, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35905625

RESUMO

Altered lipid metabolism in obesity causes pregnancy complications in humans and animals. Leptin levels increase in pregnancy, as well as obesity. However, the effect of obesity on uterine leptin receptors and its distal signaling is not clear. The present study aimed to understand the effect of increased fat on leptin signaling in rat uterus. Wistar female rats were fed with an HF diet (40% Fat, 17% Sucrose, 1.25% Cholesterol, 0.75% Cholic acid) for 6 weeks before the mating and during pregnancy. HF diet significantly increased the fat depots, liver weight, serum, and tissue cholesterol levels. It produced fatty degeneration in the liver and caused infiltration of inflammatory cells, cystic endometrial glands, and sub endometrial fibrosis of the uterus. In isometric tension experiments, leptin caused a significant increase in uterine contractions in high fat-fed animals compared to control animals. Analysis of receptor expressions revealed no significant difference between the groups. However, a significant decrease in the JAK2 and BKCaα mRNA expression was observed in the uterus of high fat-fed rats. No change in the BKCaß, eNOS, iNOS, MLCP, and MLCK mRNA expressions was noticed in the HF group compared to the control. The findings of the present study suggest that the contractile response to leptin in the uterus of high fat-fed rats may be attributed to reduced signaling through JAK2 and, lowered expressions of BKCa channel α subunits.


Assuntos
Leptina , Contração Uterina , Tecido Adiposo/metabolismo , Animais , Dieta Hiperlipídica , Gorduras na Dieta , Feminino , Janus Quinase 2/metabolismo , Obesidade/metabolismo , Gravidez , Prenhez , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar
14.
Anim Reprod Sci ; 244: 107047, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35908301

RESUMO

Anogenital distance (AGD) is related to fertility in cows, but there is little information on the association of AGD and reproduction in does. Therefore, the present study was conducted to assess the relationship between AGD and reproductive variables in Murciano-Granadina does. AGD was measured as the distance between anus and clitoris and does (n = 578) were divided into two categories of AGD, including short AGD (AGD ≤ median of AGD in studied does; n = 313) and long AGD (AGD > median of AGD in studied does; n = 265). Data of reproductive variables were retrieved from the herd database and were analyzed using multivariable statistical models, in which the potential confounding factors were included. AGD data were not normally distributed (3.78 ± 0.02 cm) and ranged from 2.70 to 5.10 cm. AGD was longer in multiparous and primiparous does than nulliparous does (P < 0.0001), and was positively associated with age and body weight (P < 0.0001). The risk of pregnancy and kidding, litter size, fecundity, proportion of male offspring and birth weight of kids were higher in long AGD does than short AGD does (P < 0.05). But abortion risk did not differ between does with long and short AGD (P > 0.05). In conclusion, the present study revealed that AGD had individual variation among Murciano-Granadina does, and does with long AGD were more fertile and more likely to produce larger, heavier and male-biased litters as compared with does with short AGD.


Assuntos
Fertilidade , Cabras , Reprodução , Canal Anal , Animais , Feminino , Cabras/anatomia & histologia , Tamanho da Ninhada de Vivíparos , Masculino , Gravidez , Prenhez
15.
Res Vet Sci ; 148: 42-51, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35660544

RESUMO

Early gestation may be the best period for sows to recover body reserve losses from previous lactation. The aim of this study was to investigate the effect of different levels of restricted feeding in early gestation on the body status, productive and reproductive performance, and hormonal-metabolic status of primiparous and multiparous sows. A total of 130 sows were randomly assigned to one of three feeding levels: Treatment I, which sows were fed at the level commonly used from day 3 to 28 of gestation (2.5 kg·d-1 of a diet with 2.18 Mcal NE·kg-1 and 13.72 g CP·kg-1), and Treatments II and III, where feed was increased by 25% and 50%, respectively. Sow body status, litter size and weight, early mortalities, reproductive rates, weaning-to-estrus interval, and hormones linked to metabolism were recorded. The highest weight gain, body condition score, and backfat thickness were found in sows fed Treatment III compared to those fed the usual feeding level (Treatment I). No differences among treatment groups were found in litter size or litter weight, although a tendency for more live born piglets and fewer stillbirths was found in sows fed Treatment III. In contrast, litters from sows fed at higher feeding levels had a higher mortality at 72 h compared to those fed at the lowest feeding level (I), which was partly linked to a higher percentage of piglets culled at birth and piglets weighing less than 800 g. There were no differences in conception and farrowing rates, leptin, progesterone, insulin, or cortisol among treatment groups applied in early gestation. In conclusion, increasing the feeding level in sows during early gestation to improve their short-term productive and reproductive performance remains controversial. Further studies are needed to focus on how the restricted feeding level applied could affect the viability and proportion of low-weight piglets.


Assuntos
Ração Animal , Dieta/veterinária , Prenhez/fisiologia , Reprodução , Suínos/fisiologia , Ração Animal/análise , Animais , Feminino , Lactação , Tamanho da Ninhada de Vivíparos , Gravidez , Suínos/metabolismo , Desmame , Aumento de Peso
16.
Anim Genet ; 53(5): 557-569, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35748198

RESUMO

Twin and multiple births have negative effects on the performance and health of cows and calves. To decipher the genetic architecture of this trait in the two Swiss Brown Swiss cattle populations, we performed various association analyses based on de-regressed breeding values. Genome-wide association analyses were executed using ~600 K imputed SNPs for the maternal multiple birth trait in ~3500 Original Braunvieh and ~7800 Brown Swiss animals. Significantly associated QTL were observed on different chromosomes for both breeds. We have identified on chromosome 11 a QTL that explains ~6% of the total genetic variance of the maternal multiple birth trait in Original Braunvieh. For the Brown Swiss breed, we have discovered a QTL on chromosome 15 that accounts for ~4% of the total genetic variance. For Original Braunvieh, subsequent haplotype analysis revealed a 90-kb window on chromosome 11 at 88 Mb, where a likely regulatory region is located close to the ID2 gene. In Brown Swiss, a 130-kb window at 75 Mb on chromosome 15 was identified. Analysis of whole-genome sequence data using linkage-disequilibrium estimation revealed possible causal variants for the identified QTL. A presumably regulatory variant in the non-coding 5' region of the ID2 gene was strongly associated with the haplotype for Original Braunvieh. In Brown Swiss, an intron variant in PRDM11, one 3' UTR variant in SYT13 and three intergenic variants 5' upstream of SYT13 were identified as candidate variants for the trait multiple birth maternal. In this study, we report for the first time QTL for the trait of multiple births in Original Braunvieh and Brown Swiss cattle. Moreover, our findings are another step towards a better understanding of the complex genetic architecture of this polygenic trait.


Assuntos
Estudo de Associação Genômica Ampla , Prole de Múltiplos Nascimentos , Prenhez , Locos de Características Quantitativas , Animais , Bovinos/genética , Cromossomos , Feminino , Estudo de Associação Genômica Ampla/veterinária , Polimorfismo de Nucleotídeo Único , Gravidez , Prenhez/genética , Sinaptotagminas/genética
17.
J Anim Sci ; 100(7)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35772752

RESUMO

Embryonic or fetal loss in cattle is associated with problems that occur during oocyte maturation, early embryonic development, conceptus elongation, maternal recognition of pregnancy (MRP), and/or placental attachment and implantation. Many of these problems manifest as inadequate or asynchronous communication between the developing conceptus and endometrium, resulting in pregnancy failure. This review will provide an overview of how various conceptus-endometrial paracrine signaling systems control the fate of early pregnancy in cattle and other ruminants. We begin by summarizing the actions of interferon-tau, the classic MRP signal in ruminates, and then explore how other secretory factors derived from either the conceptus or endometrium influence establishment and maintenance of pregnancy. Insight into how the endometrium responds to male vs. female conceptuses or conceptuses produced by in vitro methods will also be described. Specific focus will be placed on describing how "omic" technologies and other cutting-edge techniques have assisted with identifying novel conceptus and/or endometrial factors and their functions. Recent findings indicate that the endometrial transcriptome and histotroph are altered by conceptus sex, quality, and origin, suggesting that the endometrium is a sensor of conceptus biochemistry. Although the endometrium has a certain level of flexibility in terms of conceptus-maternal interactions, this interplay is not sufficient to retain some pregnancies. However, new information inspires us to learn more and will help develop technologies that mitigate early embryonic loss and reproductive failure in ruminants and other animals.


Early pregnancy losses are common in cattle. This review describes how critical the interplay between the developing conceptus (embryo and extraembryonic membranes) and endometrium is to maintaining pregnancies in cattle and other ruminants. The discovery of interferon-tau more than 40 yr ago initiated a new field of reproductive biology focused on describing how the conceptus and endometrium communicate with one another through the secretion of paracrine factors, extracellular vesicles, and other molecules. The use of "omic" and gene editing technologies has assisted with identifying novel functions for many conceptus and endometrial secreted factors. This review provides examples of how conceptus sex, quality, and in vitro vs. in vivo development influences endometrial function. The endometrium appears to have some flexibility in its response to conceptuses, and this insight could be used to our advantage as we work towards developing schemes to rescue conceptuses that are in danger of experiencing pregnancy loss.


Assuntos
Implantação do Embrião , Prenhez , Animais , Bovinos , Endométrio , Feminino , Interferon Tipo I/fisiologia , Masculino , Placenta , Gravidez , Proteínas da Gravidez/fisiologia , Ruminantes
20.
J Equine Vet Sci ; 115: 104038, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35691582

RESUMO

Practitioners are frequently requested to diagnose and stage pregnancy in donkeys with unknown breeding dates; however, scant work has been done to stage pregnancy in the species. Therefore, this study aimed to determine the association between measurements of fetal aortic, thoracic, and heartbeat with gestational age in donkeys carrying and delivering healthy foals. Multiparous Dezhou donkeys (n = 50) ranging from 4 to 16 years were enrolled in the study by 150 days of gestation. Transabdominal ultrasonography coupled with a 3.5 MHz sectorial convex transducer was performed at 30 day-intervals until delivery to obtain fetal aortic, thoracic, and fetal heartbeat measurements. Data were tested for normality with Shapiro- Wilk's test and then ANOVA and Tukey's. Statistical significance was set at P < .05. The mean duration of pregnancy was 356.6 ± 10.6 days (339-368). There were significant associations between gestational age and fetal aortic (r = 0.89) and thoracic (r = 0.88) measurements. Fetal heartbeat (r = -0.76) was negatively correlated with gestation length. The fetal aortic and thoracic measurements increased from the seventh month of gestation to the term (P < .001). The fetal heartbeat remained steady from 150 days to 270 days of gestation, then continuously decreased from 270 days until parturition (P < .001). In conclusion, fetal aortic and thoracic measurements are strongly associated with gestational age in donkeys. Fetal heartbeat decreases with advanced pregnancy.


Assuntos
Equidae , Feto , Frequência Cardíaca , Prenhez , Ultrassonografia Pré-Natal , Animais , Feminino , Feto/diagnóstico por imagem , Idade Gestacional , Gravidez , Ultrassonografia Pré-Natal/veterinária
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...