Structural and Functional Dynamics of the Ovary and Uterus during the Estrous Cycle in Donkeys in the Eastern Caribbean.

Eight non-bred, non-pregnant, regularly cycling Caribbean jennies were examined daily via transrectal ultrasound to define the ovarian and uterine dynamics during four consecutive estrous cycles. Blood samples were collected every other day for progesterone analysis. The mean (±SD) overall inter-ovulatory interval across all donkeys and cycles was 22.93 ± 1.99 days. The maximum follicular diameter was 34.6 ± 2.9 mm. A two-wave pattern was evident in 97% (30/31) of the cycles. The emergence of the future dominant follicle and the largest subordinate follicle of the major primary wave coincided on Day 5.7 ± 3.6 post-ovulation, whereas the secondary wave emerged on Day 19.8 ± 2.9 during estrus of the previous cycle or early diestrus. The secondary wave was often minor (93%, 28/30 cycles). Follicular deviation occurred 8.2 ± 1.4 days before the subsequent ovulation. Luteal volume increased for the first four days after ovulation and reached a maximum volume of 8.5 ± 2.7 mm3 at Day 5.4 ± 0.4, before gradually regressing after Day 15. Serum progesterone concentration increased from Day 1 after ovulation, peaking at 27.0 ± 9.6 ng/mL between 7 and 10 days after ovulation. Progesterone concentration dropped precipitously around Day 15 after ovulation and was below 2 ng/mL around Day 17 ± 2. A day effect (p < 0.0001) was observed for corpus luteum's volume, progesterone concentration, and uterine tone, but not for endometrial edema (p > 0.05). This study helps to clarify and define normal estrous characteristics of jennies in the Eastern Caribbean.

Morphology of Pêga jennies term placenta and its fetal-maternal interface / Morfologia da placenta a termo e da interface materno-fetal da jumenta Pêga

This study describes the placental morphology and fetal-maternal interface regarding macroscopic and microscopic aspects from Pêga Jennies at end of pregnancy. Eleven placentas were evaluated after delivery, and four fragments from each placenta were taken in duplicate corresponding to the pregnant uterine horn and non-pregnant horn. Fragments from fetal-maternal interface were obtained from one Jennie at C- section. All fragments were submitted to light microscopy and scanning electron microscopy. Regarding the macroscopic aspect of the placenta, microcotyledons were observed at the endometrial interface, characterized by the diffuse aspect of the placenta. Light microscopy revealed villous type chorion at the chorioallantoic membrane, which were organized in agglomeration villi, presenting a connective tissue stroma and trophoblastic cells. At the fetal-maternal interface, micro placentation, which were composed by inter digitations of agglomeration of villi, limited by maternal crypts, circled by arcades, composed by a fetal trophoblast and an internal portion. In addition, endometrial glands opening were observed. Scanning electron microscopy revealed that the chorioallantoic membranes were covered by villi agglomerations. At the top of those fetal villi we observed cell protrusions from trophoblast cells, which carried debris from maternal tissues. A transversal section from the fetal- maternal interface represented an intricate villi interdigitation with thin maternal caruncle structures, which consist in micro placentation. Macro and microscopic aspects of Jennies placenta, as well as the fetalmaternal interface presented similarities with the observed in mares.(AU)

O presente trabalho descreveu a morfologia placentária e a interface materno-fetal de jumentas da raça Pêga, quanto aos aspectos macroscópicos e microscópicos ao final da gestação. Foram avaliadas onze placentas, colhendo-se quatro fragmentos por placenta em duplicata, correspondentes ao corno uterino prenhe e ao corno uterino não prenhe. Fragmentos da interface materno-fetal, oriundos de uma jumenta com gestação a termo, foram obtidos durante o procedimento de cesariana. Os fragmentos foram examinados por microscopia de luz e microscopia eletrônica de varredura. Na macroscopia, foi observado microcotilédone na interface com o endométrio caracterizando placentação difusa. À microscopia de luz na membrana corioalantoide foi observado o córion do tipo viloso, com vilos organizados em tufos vilosos, estroma de tecido conjuntivo e células trofoblásticas. Na interface materno-fetal, microplacentônios, formados pela interdigitação dos tufos vilosos, limitados pelas criptas maternas, circundados pelas arcadas, compostos por uma parte fetal trofoblástica e uma parte interna, observando-se a abertura de glândulas endometriais. À microscopia eletrônica de varredura, foi constatado que a membrana corioalantoide se encontrava coberta por tufos vilosos. Nos ápices dos vilos fetais, foram observadas protrusões de células do trofoblasto, carreando debris de tecidos maternos. Em corte transversal da interface materno-fetal, foi verificada a intrincada interdigitação dos vilos com as finas estruturas das carúnculas maternas, formando os microplacentônios. Os aspectos macro e microscópicos da placenta da jumenta, assim como as descrições da interface materno-fetal apresentaram similaridades com os observados na égua.(AU)

Morphology of Pêga jennies term placenta and its fetal-maternal interface / Morfologia da placenta a termo e da interface materno-fetal da jumenta Pêga

This study describes the placental morphology and fetal-maternal interface regarding macroscopic and microscopic aspects from Pêga Jennies at end of pregnancy. Eleven placentas were evaluated after delivery, and four fragments from each placenta were taken in duplicate corresponding to the pregnant uterine horn and non-pregnant horn. Fragments from fetal-maternal interface were obtained from one Jennie at C- section. All fragments were submitted to light microscopy and scanning electron microscopy. Regarding the macroscopic aspect of the placenta, microcotyledons were observed at the endometrial interface, characterized by the diffuse aspect of the placenta. Light microscopy revealed villous type chorion at the chorioallantoic membrane, which were organized in agglomeration villi, presenting a connective tissue stroma and trophoblastic cells. At the fetal-maternal interface, micro placentation, which were composed by inter digitations of agglomeration of villi, limited by maternal crypts, circled by arcades, composed by a fetal trophoblast and an internal portion. In addition, endometrial glands opening were observed. Scanning electron microscopy revealed that the chorioallantoic membranes were covered by villi agglomerations. At the top of those fetal villi we observed cell protrusions from trophoblast cells, which carried debris from maternal tissues. A transversal section from the fetal- maternal interface represented an intricate villi interdigitation with thin maternal caruncle structures, which consist in micro placentation. Macro and microscopic aspects of Jennies placenta, as well as the fetalmaternal interface presented similarities with the observed in mares.

O presente trabalho descreveu a morfologia placentária e a interface materno-fetal de jumentas da raça Pêga, quanto aos aspectos macroscópicos e microscópicos ao final da gestação. Foram avaliadas onze placentas, colhendo-se quatro fragmentos por placenta em duplicata, correspondentes ao corno uterino prenhe e ao corno uterino não prenhe. Fragmentos da interface materno-fetal, oriundos de uma jumenta com gestação a termo, foram obtidos durante o procedimento de cesariana. Os fragmentos foram examinados por microscopia de luz e microscopia eletrônica de varredura. Na macroscopia, foi observado microcotilédone na interface com o endométrio caracterizando placentação difusa. À microscopia de luz na membrana corioalantoide foi observado o córion do tipo viloso, com vilos organizados em tufos vilosos, estroma de tecido conjuntivo e células trofoblásticas. Na interface materno-fetal, microplacentônios, formados pela interdigitação dos tufos vilosos, limitados pelas criptas maternas, circundados pelas arcadas, compostos por uma parte fetal trofoblástica e uma parte interna, observando-se a abertura de glândulas endometriais. À microscopia eletrônica de varredura, foi constatado que a membrana corioalantoide se encontrava coberta por tufos vilosos. Nos ápices dos vilos fetais, foram observadas protrusões de células do trofoblasto, carreando debris de tecidos maternos. Em corte transversal da interface materno-fetal, foi verificada a intrincada interdigitação dos vilos com as finas estruturas das carúnculas maternas, formando os microplacentônios. Os aspectos macro e microscópicos da placenta da jumenta, assim como as descrições da interface materno-fetal apresentaram similaridades com os observados na égua.