RESUMO

Monitoring equine parturition effectively is essential for preemptive intervention in periparturient issues and ensuring the overall well-being of both mares and foals. However, its implementation in breeding farms is challenging due to variable gestational lengths and nocturnal births. Predictive techniques have the potential to streamline the monitoring process, reduce labor intensity, and minimize costs. Research on foaling prediction in mares carrying mule or equine clone fetuses is scarce. Therefore, this study aimed to comparatively analyze foaling prediction parameters in mares pregnant with mule, equine, or equine clone fetus. The study included vulvar relaxation, sacroiliac ligament tension, pH, BRIX index, and concentrations of calcium, phosphorus, magnesium, sodium, and potassium in prepartum mammary secretions. Sixty pregnant mares were used for this study and grouped as follows: 25 mares with mule fetuses (MF), 20 with equine clone fetuses (CF), and 15 with equine control fetuses (EF). Results showed significant differences in vulvar relaxation and sacroiliac ligament tension only in MF group (p < 0.05) on the day of parturition compared to the other days evaluated, different from the other groups. Levels of pH notably decreased on parturition day (mean 5.7 ± 0.04, p < 0.0001), with lower values in MF (6.05 ± 0.02) and CF (6.08 ± 0.04) compared to EF (6.26 ± 0.04) (p < 0.03). The BRIX index showed variation across mares and was not a good parameter for foaling prediction. Electrolytes correlated positively with impending parturition, showing no significant differences among groups. The MF and CF groups exhibited a substantial increase (102.13 % and 110.66 %, respectively) in mean calcium concentrations on the day before foaling, unlike EF (38.29 %). In conclusion, the pH values were different in mammary secretions between mares carrying mule and clone fetuses, in contrast to equine control fetuses. Nevertheless, there was a trend of decreasing pH values closer to parturition in all groups. Conversely, the BRIX index serves as a valuable indicator of colostrum quality yet does not offer insights into the proximity of parturition. While electrolyte concentrations did not reveal significant differences among groups, it is worth noting that the evaluation of phosphorus emerges as a new parameter to explore in mares nearing parturition, since it obtained a pattern similar to calcium.

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This retrospective study aimed at identifying factors that contribute to the success of equine in vitro embryo production by intracytoplasmic sperm injection (ICSI). A total of 7993 ovum pick-up (OPU) sessions were performed, totaling 2540 donor mares and semen from 396 stallions. Oocytes were aspirated at multiple sites in Brazil and were sent to the laboratory, within 6 h from OPU, in pre-maturation medium where they were in vitro matured (IVM) followed by ICSI and in vitro embryo culture for 7-8 days. The number of recovered oocytes, matured oocytes, cleaved embryos and blastocysts were used to explore the effect of age and breed of the donor mare, time of year in which the mare was aspirated and phase of the estrous cycle on the day of follicular aspiration. Mares between 6 and 15 years old were superior to other age groups in most parameters evaluated, including the average number of blastocysts per OPU. The impact of age was similar when evaluated within two breeds, American Quarter Horse (AQHA) and Warmblood mares. We observed that breed (AQHA, Warmblood, Crioulo, Lusitano and Mangalarga) had an important effect on most of the parameter evaluated, including number of oocytes recovered, blastocysts produced per OPU, and blastocyst rates. The overall impact of season was less pronounced than age and breed, with the only statistically significant difference being a higher rate of oocyte maturation during the summer season. Finally, most of the parameters evaluated were superior in follicular phase mares, with or without dominant follicle than luteal phase mares. In conclusion, this retrospective study revealed that breed, age, season and stage of estrous at the time of OPU are all important parameters for the success of equine embryo production by ICSI. This technology enables producing embryos all-year-round from mares of different breeds and ages from OPU-derived oocytes collected at multiple sites.

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After parturition, a rapid transition occurs from the intrauterine to the extrauterine milieu, exposing neonates to physiological circumstances characterized by oxidative conditions that instigate the generation of reactive oxygen species. These free radicals play pivotal roles in physiological processes; however, an imbalance between their production and the removal of antioxidants can result in severe cellular damage. The main objective of this study was to compare the oxidative and antioxidant profiles in mule and horse neonates immediately post-parturition, as well as at subsequent time points (1, 6, 12, and 24 h, 7 and 30 days) during their extrauterine existence. The parameters assessed included the systemic concentrations of Thiobarbituric Acid Reactive Substances (TBARS) and carbonyl groups; the activities of the antioxidants superoxide dismutase (SOD) and glutathione peroxidase (GPx); and the levels of the total, indirect, and direct bilirubin. Our results showed no interaction effect between the neonatal groups and the assessed time points for the variables under investigation. Notably, the concentrations of TBARS, as a marker of lipid peroxidation, and bilirubin were consistently lower in the mules, whereas the glutathione peroxidase (GPx) activity exhibited higher levels in this group. The bilirubin levels were notably reduced in the mule neonates. The TBARS demonstrated a progressive decrease over the observation period in both groups, while the GPx activity remained relatively stable from birth to 7 days, with a substantial increase evident at the 30-day mark. Protein oxidation was not affected by the group and time, while for the SOD values, all times were statistically similar, except for the lower activity at T1h. Consequently, our findings lead us to the conclusion that neonatal mules and horses manifest distinct patterns of oxidative activity and antioxidant capacity during the initial month of their extrauterine existence, potentially indicative of different adaptation mechanisms to the extrauterine environment.

RESUMO

Mules are derived from crossing horse mares with a donkey, in which the interest is due to gentleness and ability to work and equestrian sports. As the placenta is responsible for fetal development and maturation, knowing its typical microstructure allows us to understand how fetomaternal interactions occur in this interspecific pregnancy. Thus, the study performed a comparative stereological evaluation of volumetric composition and fetomaternal contact surface in the uterine body (UB), gravid uterine horn (GUH), and nongravid uterine horn (NGUH) of Mangalarga Paulista mare's term allantochorion membrane in mule and equine pregnancies. In equine gestation, the UB microcotyledon surface density was negatively correlated with the NGUH absolute area and the total volume of microvilli. In mule gestation, the base width and the number of microcotyledon were negatively correlated with the height and number of microcotyledons in the NGUH. Mule also showed a negative correlation between (1) the UB microcotyledon surface density and the GUH microcotyledons number per unit of membrane length, (2) the GUH total volume and the NGUH microcotyledon number. Such differences demonstrate a compensatory mechanism in conversion capacity among macrocompartments. A trend toward a greater total volume of allantoid vessels and total volume of allantoid mesoderm in UB microvilli was found in the equine and mule groups, respectively. There was a significant increase in the base width of microcotyledons in the NGUH of mules versus horses. These finds possibly influence the exchange capacity of each placental microregion and suggest a difference between mule versus horse term allantochorion membrane.

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Challenges of the extrauterine environment can be life threatening for a premature fetus with inadequate fetal maturity. Maternal corticosteroids therapy is widely employed to induce fetal pulmonary maturation. Nevertheless, whenever therapeutic pregnancy interruption has to be performed in a time manner insufficient to treat the dam, postnatal corticotherapy can be considered an alternative. However, it is not known if antenatal and postnatal corticotherapy can improve similarly neonatal outcomes and pulmonary function. This research aimed to analyze antenatal and postnatal corticotherapy on premature lambs vitality, pulmonary functioning, metabolic and oxidative status. Lambs were evaluated according to the mode of treatment: Prenatal Corticosteroid Group (8 lambs born after maternal betamethasone treatment 48 h prior to birth), Postnatal Corticosteroid Group (9 lambs subjected to betamethasone treatment 10 min after birth) and Control Group (5 lambs remained untreated). Lambs were medically followed-up from birth to 72 h thereafter through a complete physical examination, as well as lactatemia, glycaemia, blood acid-base balance and antioxidant status. Treated lambs had higher vitality score than the Control Group. Heart rate was higher in postnatal therapy compared to prenatal treatment. Respiratory rate and rectal temperature were higher in treated groups. Treated lambs had hyperglycemia, while the Postnatal Group had higher lactatemia than the Control Group. The Prenatal Group had lower and normal pCO2 from 60 min onwards. The Postnatal Group had higher superoxide dismutase activity than untreated lambs. In conclusion, prenatal and postnatal betamethasone treatments favor neonatal clinical outcome, respiratory function, glucose homeostasis and oxidative balance.

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RESUMO

Os muares são híbridos, provenientes do cruzamento de éguas com jumentos e que apresentam um número cromossômico diplóide (2n = 63). Estes animais herdam a combinação de traços comportamentais de ambas as espécies base, e demonstram frequentemente vigor híbrido nas suas características físicas e cognitivas. A popularidade, bem como o interesse econômico tem crescido, devido as características como docilidade, rusticidade e habilidades para atividades de trabalho e esporte. Entretanto, existe uma nítida falta de informação sobre híbridos muares, desde parâmetros gestacionais, a comportamentais, físicos e fisiológicos dos neonatos. Esta revisão, tem por objetivo trazer as informações da literatura e resultados das últimas pesquisas desenvolvidas pelo LEPPE (Laboratório de Estudos da Prenhez e Periparto em Equídeos), sobre parâmetros de éguas gestantes de potros híbridos muares, bem como parâmetros neonatais. A principal finalidade, é permitir um correto manejo e uma abordagem clínica, permitindo a identificação e intervenção precoce em problemas.

Mules are hybrids, products of mares and donkeys, with a diploid chromossomic number (2n = 63). These animals inherit a combination of behavioral traits from both species and often show hybrid vigor in their physical and cognitive characteristics. Their popularity, as well as their economic value, has increased because of their characteristics such as docility, rusticity, and ability for work and pleasure. However, there is a lack of published information about hybrid mules, such as gestational, behavioral, physical, and physiological neonatal parameters. Therefore, this review aims to bring published information and results from the most current research projects developed by LEPPE (Laboratory of the Study of Pregnancy and Peripartum in Equids), about parameters of pregnant mares with mule foals, as well as neonatal parameters. The main purpose is to assist in the correct management and clinical approach, allowing diagnosis and early intervention when there are problems.

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It has been shown in ruminants that increased dietary protein leading to elevated blood urea nitrogen concentrations (BUN) can be a factor in decreased survival of early embryos. This work is a review of the effects of elevated BUN on endometrium and embryos from mares. An experimental model was used to elevate BUN with intravenous urea infusion, acute treatment, or oral urea, chronic treatment. After the acute urea treatment there was a decrease in uterine pH and changes in genes related to cell pH and ion homeostasis. After the chronic urea treatment there was no difference in uterine pH but genes related to necrosis and cellular movement had a different expression. The effect of high BUN was also evaluated on equine embryo transcriptome, with a positive correlation between plasma BUN and blastocoele fluid urea nitrogen concentration. Additionally, the expression of genes related to survival of organism and adhesion were different. Lastly, using mares from private farms, lower pregnancy rate was seen when embryos were collected from mares with higher BUN concentrations. In conclusion, these novel results show that high BUN results in endometrial and embryonic alterations, suggesting that it might lead to decreased fertility.

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RESUMO

Equine piroplasmosis, disease globally responsible for significant economic losses, is caused by the transmission of the hemoprotozoa Theileria equi and Babesia caballi by ticks. Transplacental transmission has been reported previously in horses, which is not the case for mules´ foals. The present study investigated, by Real Time-PCR (RT-PCR), the presence of both Theileria equi and Babesia caballi in newborn mules before the ingestion of colostrum. Blood samples of 18 mares and their respective mules´ foals were collected and analyzed by RT-PCR. Only one mare was positive for B. caballi. In contrast, 13 mares were positive for T. equi, with two foals (11.1%) positive for the same protozoon, both of affected mares. We may conclude that transplacental transmission of Theileria equi also occurs in mules which may be an important concern while breeding such animals.

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During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO2 (10.67 ± 5.65 mmHg) and SO2 (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO2 and pO2 . Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.(AU)

Assuntos

RESUMO

During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO2 (10.67 ± 5.65 mmHg) and SO2 (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO2 and pO2 . Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.

Assuntos

RESUMO

During pregnancy, fetal lambs are exposed to low oxygen tension. Thus, an effective antioxidant mechanism is partially developed which sensitizes fetus to oxidative stress. Consequently, term and preterm neonates are susceptible to molecular and cellular injury caused by oxygen species (ROS). This study aimed to evaluate the development of antioxidant enzymes and oxidative profile of preterm (135 days of pregnancy) and term (145 days of pregnancy) neonatal lambs, correlating with clinical analysis. Preterm lambs had significantly (P ≤ 0.05) lower score of vitality (4.00 ± 1.10), bradycardia (99 ± 34 bpm) and bradypnea (13 ± 10 mpm). However, both groups were normothermic and euglycemic. Preterm group had low blood pH (7.07 ± 0.10) and both groups had hypercapnia, more severe in preterm group (85.52 ± 18.65 mmHg). In addition, premature newborns had lower pO2 (10.67 ± 5.65 mmHg) and SO2 (6.17 ± 5.85%) values. No significant difference (P ≥ 0.05) on antioxidant enzymes and oxidative stress were verified among experimental groups, although glutathione peroxidase negatively correlated with Apgar score, heart rate, SO2 and pO2. Our data show that preterm neonates are less adapted to the odds of labor and to overcome the immediate changes of extra-uterine life. Furthermore, we verified an influence of glutathione peroxidase in controlling oxidative stress, which highlights mature enzymatic mechanisms of cell redox, even in premature lambs.

RESUMO

Uma placenta normal e eficiente que desempenhe suas funções é um pré-requisito indispensável paraque a gestação seja conduzida com sucesso, permitindo o desenvolvimento e maturação fetal e resultando nonascimento de um produto sadio e com desenvolvimento adequado. Assim, um conjunto de avaliações queforneçam dados sobre as características maternas, eficiência placentária e monitoramento da gestação são deextrema importância para a criação e o mercado equestre. Têm sido demonstrada uma relação entra ascaracterísticas macro e microscópicas da placenta e viabilidade de potros ao nascimento. Dessa forma, oconhecimento das mudanças na estrutura e função placentária que são influenciadas pelo porte, idade e paridadematerna, e por sua vez, possam refletir no desenvolvimento e crescimento do feto, são de grande importânciapara uma melhor seleção e manejo das matrizes e/ou receptoras, que serão responsáveis por gestar um potro.

A normal and efficient placenta that fulfills its functions is an essential prerequisite in order to have aterm pregnancy, allowing fetal development and maturation resulting in the birth of a healthy, well developedfoal. Therefore, several evaluations that provide information on maternal characteristics, placental efficiencyand pregnancy monitoring are of extreme importance for equine breeding industry. A relationship betweenmacro and microscopic placental characteristics and foals’ viability at birth has been detected. Thus, theknowledge of the changes of structure and placental function that are influenced by size, age and maternalparity which can reflect in development and growth of the fetus are of major importance for a better selectionand management of broodmares and/or recipients that will carry a foal to term.

Assuntos

RESUMO

Muitos são os hormônios envolvidos no período de gestação da égua, sendo um evento muito complexodo que um simples predomínio progesterônico como muitos acreditam. Da mesma forma, o processo do parto,não é atribuído a um gatilho hormonal isolado, mas sim uma cascata de alterações endócrinas que atuam em umasequência ordenada. Estes hormônios circulantes na égua gestante, são produzidos por precursores fetais,metabolizados na placenta e com principal ação no útero materno. Embora a maioria dos hormônios envolvidosna gestação e parto sejam comuns entre as espécies de mamíferos, alguns aspectos da secreção degonadotrofinas, progesterona e esteroides pela unidade feto-placentária são exclusivos na égua. Assim, oconceito de cooperação interdependente entre placenta, feto e endométrio torna-se fundamental nessa espécie,primando a manutenção da gestação, desenvolvimento fetal e desencadeamento do parto.

Several hormones are involved throughout pregnancy and it is a lot more complex than theprogesterone predominance as believed. Likewise, the process of parturition is not an event attributed to anisolated hormonal trigger but a cascade of endocrinological alterations that act in a coordinated sequence.These circulating hormones in the pregnant mare are produced by fetal precursors, metabolized by the placentaand act mainly in maternal uterus. Although most hormones involved in pregnancy and parturition are commonamong mammalian species, some aspects of fetoplacental secretion of gonadotrophins, progesterone andsteroids are unique in the mare. Thus, the concept of interrelationship between placenta, fetus and endometriumis fundamental in this species, aiming pregnancy maintenance, fetal development and triggering of parturition.

Assuntos

RESUMO

Muitos são os hormônios envolvidos no período de gestação da égua, sendo um evento muito complexodo que um simples predomínio progesterônico como muitos acreditam. Da mesma forma, o processo do parto,não é atribuído a um gatilho hormonal isolado, mas sim uma cascata de alterações endócrinas que atuam em umasequência ordenada. Estes hormônios circulantes na égua gestante, são produzidos por precursores fetais,metabolizados na placenta e com principal ação no útero materno. Embora a maioria dos hormônios envolvidosna gestação e parto sejam comuns entre as espécies de mamíferos, alguns aspectos da secreção degonadotrofinas, progesterona e esteroides pela unidade feto-placentária são exclusivos na égua. Assim, oconceito de cooperação interdependente entre placenta, feto e endométrio torna-se fundamental nessa espécie,primando a manutenção da gestação, desenvolvimento fetal e desencadeamento do parto.(AU)

Several hormones are involved throughout pregnancy and it is a lot more complex than theprogesterone predominance as believed. Likewise, the process of parturition is not an event attributed to anisolated hormonal trigger but a cascade of endocrinological alterations that act in a coordinated sequence.These circulating hormones in the pregnant mare are produced by fetal precursors, metabolized by the placentaand act mainly in maternal uterus. Although most hormones involved in pregnancy and parturition are commonamong mammalian species, some aspects of fetoplacental secretion of gonadotrophins, progesterone andsteroids are unique in the mare. Thus, the concept of interrelationship between placenta, fetus and endometriumis fundamental in this species, aiming pregnancy maintenance, fetal development and triggering of parturition.(AU)

Assuntos

RESUMO

Uma placenta normal e eficiente que desempenhe suas funções é um pré-requisito indispensável paraque a gestação seja conduzida com sucesso, permitindo o desenvolvimento e maturação fetal e resultando nonascimento de um produto sadio e com desenvolvimento adequado. Assim, um conjunto de avaliações queforneçam dados sobre as características maternas, eficiência placentária e monitoramento da gestação são deextrema importância para a criação e o mercado equestre. Têm sido demonstrada uma relação entra ascaracterísticas macro e microscópicas da placenta e viabilidade de potros ao nascimento. Dessa forma, oconhecimento das mudanças na estrutura e função placentária que são influenciadas pelo porte, idade e paridadematerna, e por sua vez, possam refletir no desenvolvimento e crescimento do feto, são de grande importânciapara uma melhor seleção e manejo das matrizes e/ou receptoras, que serão responsáveis por gestar um potro.(AU)

A normal and efficient placenta that fulfills its functions is an essential prerequisite in order to have aterm pregnancy, allowing fetal development and maturation resulting in the birth of a healthy, well developedfoal. Therefore, several evaluations that provide information on maternal characteristics, placental efficiencyand pregnancy monitoring are of extreme importance for equine breeding industry. A relationship betweenmacro and microscopic placental characteristics and foals viability at birth has been detected. Thus, theknowledge of the changes of structure and placental function that are influenced by size, age and maternalparity which can reflect in development and growth of the fetus are of major importance for a better selectionand management of broodmares and/or recipients that will carry a foal to term.(AU)

Assuntos

RESUMO

A placenta é o órgão de ligação entre a égua e o potro e é um dos principais responsáveis pelo desenvolvimento fetal e pelas características morfométricas do neonato. Essa função se torna cada vez mais importante porque os estudos indicam que as características físicas dos potros predizem o seu desenvolvimento na vida adulta. Desta forma, o objetivo do presente estudo foi correlacionar número de partos (1-5) e características maternas de éguas com as características placentárias e o tamanho do potro. As éguas foram categorizadas em grupos de acordo com o número de partos sendo G1: 1 parto (n=4); G2: 2 partos (n=6); G3: 3 partos (n=7); G4: 4 partos (n=5); e G5: 5 partos (n=3). Como principais resultados obtidos, o perímetro torácico e o peso da égua pré- e pós-parto influenciaram positivamente peso (p=0,004/ R= 0,51; p=0,002/ R= 0,55; p=0,01/ R= 0,43), altura (p=0,0005/ R= 0,60; p=0,001/ R= 0,57; p=0,005/ R= 0,50) e perímetro torácico (p=0,0001/ R= 0,65; p≤0,0001/ R= 0,71; p=0,0002/ R= 0,64) dos potros ao nascimento. Éguas com maior peso corporal no pré-parto apresentaram maior peso placentário (p=0,01/R= 0,45) e pariram potros mais pesados (p=0,003/ R= 0,52) com maior perímetro torácico (p=0,01/ R= 0,45). Os neonatos de éguas do G4 foram os mais pesados, indicando que provavelmente o maior tamanho uterino em éguas pluríparas permita uma maior cobertura placentária, maior área de contato materno fetal e provavelmente maior aporte de nutrientes ao feto.(AU)

The placenta connects the mare and the foal and it is one of the main organs responsible for fetal development and newborns morphometric characteristics. This function becomes even more important because a number of studies indicates that foals physical characteristics are able to predict their development in adult life. Therefore, the aim of this study was to correlate mares parity (1-5) and maternal characteristics with placental characteristics as well as foals size. Mares were categorized according to parity in G1: 1 parturation (n=4); G2: 2 parturations (n=6); G3: 3 parturations (n=7); G4: 4 parturations (n=5); and G5: 5 parturations (n=3). Results indicate that the mares pre- and post-parturition thoracic perimeter and weight had a positive correlation on foals weight (p=0.004/ R= 0.51; p=0.002/ R= 0.55; p=0.01/ R= 0.43), height (p=0.0005/ R= 0.60; p=0.001/ R= 0.57; p=0.005/ R= 0,50), and thoracic perimeter (p=0.0001/ R= 0.65; p≤0.0001/ R= 0.71; p=0.0002/ R= 0.64) at birth. Mares that were heavier at pre-partum had greater placental weight (p=0.01/R= 0.45) and delivered heavier foals (p=0.003/ R= 0.52) with greater thoracic perimeter (p=0.01/ R= 0.45). Foals of mares in G4 were heavier, probably indicating that the greater uterine size in multiparous mares allows greater placental coverage, greater fetomaternal surface contact and probably greater supply of nutrient to the fetus.(AU)

Assuntos

RESUMO

Abstract The placenta connects the mare and the foal and it is one of the main organs responsible for fetal development and newborns morphometric characteristics. This function becomes even more important because a number of studies indicates that foals physical characteristics are able to predict their development in adult life. Therefore, the aim of this study was to correlate mares parity (1-5) and maternal characteristics with placental characteristics as well as foals size. Mares were categorized according to parity in G1: 1 parturation (n=4); G2: 2 parturations (n=6); G3: 3 parturations (n=7); G4: 4 parturations (n=5); and G5: 5 parturations (n=3). Results indicate that the mares pre- and post-parturition thoracic perimeter and weight had a positive correlation on foals weight (p=0.004/ R= 0.51; p=0.002/ R= 0.55; p=0.01/ R= 0.43), height (p=0.0005/ R= 0.60; p=0.001/ R= 0.57; p=0.005/ R= 0,50), and thoracic perimeter (p=0.0001/ R= 0.65; p0.0001/ R= 0.71; p=0.0002/ R= 0.64) at birth. Mares that were heavier at pre-partum had greater placental weight (p=0.01/R= 0.45) and delivered heavier foals (p=0.003/ R= 0.52) with greater thoracic perimeter (p=0.01/ R= 0.45). Foals of mares in G4 were heavier, probably indicating that the greater uterine size in multiparous mares allows greater placental coverage, greater fetomaternal surface contact and probably greater supply of nutrient to the fetus.

Resumo A placenta é o órgão de ligação entre a égua e o potro e é um dos principais responsáveis pelo desenvolvimento fetal e pelas características morfométricas do neonato. Essa função se torna cada vez mais importante porque os estudos indicam que as características físicas dos potros predizem o seu desenvolvimento na vida adulta. Desta forma, o objetivo do presente estudo foi correlacionar número de partos (1-5) e características maternas de éguas com as características placentárias e o tamanho do potro. As éguas foram categorizadas em grupos de acordo com o número de partos sendo G1: 1 parto (n=4); G2: 2 partos (n=6); G3: 3 partos (n=7); G4: 4 partos (n=5); e G5: 5 partos (n=3). Como principais resultados obtidos, o perímetro torácico e o peso da égua pré- e pós-parto influenciaram positivamente peso (p=0,004/ R= 0,51; p=0,002/ R= 0,55; p=0,01/ R= 0,43), altura (p=0,0005/ R= 0,60; p=0,001/ R= 0,57; p=0,005/ R= 0,50) e perímetro torácico (p=0,0001/ R= 0,65; p0,0001/ R= 0,71; p=0,0002/ R= 0,64) dos potros ao nascimento. Éguas com maior peso corporal no pré-parto apresentaram maior peso placentário (p=0,01/R= 0,45) e pariram potros mais pesados (p=0,003/ R= 0,52) com maior perímetro torácico (p=0,01/ R= 0,45). Os neonatos de éguas do G4 foram os mais pesados, indicando que provavelmente o maior tamanho uterino em éguas pluríparas permita uma maior cobertura placentária, maior área de contato materno fetal e provavelmente maior aporte de nutrientes ao feto.

RESUMO

A placenta é o órgão de ligação entre a égua e o potro e é um dos principais responsáveis pelo desenvolvimento fetal e pelas características morfométricas do neonato. Essa função se torna cada vez mais importante porque os estudos indicam que as características físicas dos potros predizem o seu desenvolvimento na vida adulta. Desta forma, o objetivo do presente estudo foi correlacionar número de partos (1-5) e características maternas de éguas com as características placentárias e o tamanho do potro. As éguas foram categorizadas em grupos de acordo com o número de partos sendo G1: 1 parto (n=4); G2: 2 partos (n=6); G3: 3 partos (n=7); G4: 4 partos (n=5); e G5: 5 partos (n=3). Como principais resultados obtidos, o perímetro torácico e o peso da égua pré- e pós-parto influenciaram positivamente peso (p=0,004/ R= 0,51; p=0,002/ R= 0,55; p=0,01/ R= 0,43), altura (p=0,0005/ R= 0,60; p=0,001/ R= 0,57; p=0,005/ R= 0,50) e perímetro torácico (p=0,0001/ R= 0,65; p≤0,0001/ R= 0,71; p=0,0002/ R= 0,64) dos potros ao nascimento. Éguas com maior peso corporal no pré-parto apresentaram maior peso placentário (p=0,01/R= 0,45) e pariram potros mais pesados (p=0,003/ R= 0,52) com maior perímetro torácico (p=0,01/ R= 0,45). Os neonatos de éguas do G4 foram os mais pesados, indicando que provavelmente o maior tamanho uterino em éguas pluríparas permita uma maior cobertura placentária, maior área de contato materno fetal e provavelmente maior aporte de nutrientes ao feto.

The placenta connects the mare and the foal and it is one of the main organs responsible for fetal development and newborn’s morphometric characteristics. This function becomes even more important because a number of studies indicates that foals physical characteristics are able to predict their development in adult life. Therefore, the aim of this study was to correlate mares parity (1-5) and maternal characteristics with placental characteristics as well as foals size. Mares were categorized according to parity in G1: 1 parturation (n=4); G2: 2 parturations (n=6); G3: 3 parturations (n=7); G4: 4 parturations (n=5); and G5: 5 parturations (n=3). Results indicate that the mares pre- and post-parturition thoracic perimeter and weight had a positive correlation on foals weight (p=0.004/ R= 0.51; p=0.002/ R= 0.55; p=0.01/ R= 0.43), height (p=0.0005/ R= 0.60; p=0.001/ R= 0.57; p=0.005/ R= 0,50), and thoracic perimeter (p=0.0001/ R= 0.65; p≤0.0001/ R= 0.71; p=0.0002/ R= 0.64) at birth. Mares that were heavier at pre-partum had greater placental weight (p=0.01/R= 0.45) and delivered heavier foals (p=0.003/ R= 0.52) with greater thoracic perimeter (p=0.01/ R= 0.45). Foals of mares in G4 were heavier, probably indicating that the greater uterine size in multiparous mares allows greater placental coverage, greater fetomaternal surface contact and probably greater supply of nutrient to the fetus.

Assuntos

RESUMO

This review intends to show the main factors that may affect intrauterine growth and the placentals nutrients supply to the fetus, morphofunctional aspects placental efficiency, correlating them with performance indexes, such as breed, age and pluriparious. This study aims to discuss the interrelationships that determine greater placental efficiency, proposing a comparative parallel between various species in order to understand more about the placental efficiency in the equine species.

Esta revisão de literatura propõe levantar os principais fatores que podem influenciar o crescimento intrauterino e o suprimento de nutrientes placentários para o feto, abordando aspectos morfofuncionais relacionados à eficiência placentária, correlacionando-os com aspectos zootécnicos, como raça, pluriparidade e idade das fêmeas gestantes. O objetivo foi estabelecer as interrelações que determinem maior eficiência placentária, propondo um paralelo comparativo entre espécies a fim de ser entendida a eficiência placentária na espécie equina.

Assuntos

RESUMO

This review intends to show the main factors that may affect intrauterine growth and the placentals nutrients supply to the fetus, morphofunctional aspects placental efficiency, correlating them with performance indexes, such as breed, age and pluriparious. This study aims to discuss the interrelationships that determine greater placental efficiency, proposing a comparative parallel between various species in order to understand more about the placental efficiency in the equine species. (AU)

Esta revisão de literatura propõe levantar os principais fatores que podem influenciar o crescimento intrauterino e o suprimento de nutrientes placentários para o feto, abordando aspectos morfofuncionais relacionados à eficiência placentária, correlacionando-os com aspectos zootécnicos, como raça, pluriparidade e idade das fêmeas gestantes. O objetivo foi estabelecer as interrelações que determinem maior eficiência placentária, propondo um paralelo comparativo entre espécies a fim de ser entendida a eficiência placentária na espécie equina. (AU)

Assuntos