Corpus luteum blood flow evaluation on Day 21 to improve the management of embryo recipient herds

AbstractThe aim of the present study was to use blood flow evaluation of the CL at 14 days after embryo transfer to detect nonpregnant animals and optimize the management of bovine recipients. The estrous cycle was synchronized in 165 recipients, and the day of expected ovulation was considered to be Day 0. Embryo transfer was performed 7 days later, on Day 7. On Day 21, pregnancy was diagnosed on the basis of blood flow evaluation of the CL (DG21—predictive diagnostic). To validate this methodology, visual scores for blood flow were compared to objective data extracted from CL ultrasound images recorded in the Doppler mode. The size was also evaluated using recorded images of the CL in the B mode. Blood samples were also collected for further analysis of the progesterone (P4) concentration. The diagnosis of pregnancy was confirmed at 35 days after estrus (DG35—definitive diagnostic). The DG21 showed that 55.2% (90 of 163) of the animals were presumptively pregnant, and this value was higher (P < 0.04) than that obtained at DG35 (43.6%, 71 of 163). The predictive diagnostic achieved moderate specificity (79.3%) for the detection of pregnancy, but most importantly, high sensitivity (100%) for the detection of nonpregnant recipients. The overall accuracy of the diagnosis was 88.3%. The P4 concentrations were different (P < 0.02) and correlated with each visual score assigned for the CL size. Visual scores for CL blood flow were also efficient (P < 0.0001) to distinguish animals with different levels of P4; however, P4 concentrations were higher for scores 1 and 2 (high and regular blood flow, respectively) than those for score 3 (low blood flow). This technique showed high sensitivity and facilitated the early detection of nonpregnant animals. The DG21 would allow about 79.3% of nonpregnant animals to be resynchronized 9 to 14 days earlier, when compared to conventional management based on pregnancy diagnosis at Days 30 to 35

Relative expression of mRNAs related to cavitation process in bovine embryos produced in vivo and in vitro

The objectives of this work were to identify and to evaluate possible differences on gene expression of aquaporins and Na/K-ATPases transcripts between embryos in vivo and in vitro produced. For each group, 15 blastocysts distributed in three pools were used for RNA extraction followed by amplification and reverse transcription. The resulting cDNAs were submitted to Real-Time PCR, using the GAPDH gene as endogenous control. It was not possible to identify AQP1 transcripts. Relative expression of AQP3 (1.33 ± 0.78) and AQP11 (2.00 ± 1.42) were not different in blastocysts in vitro and in vivo produced. Na/K-ATPase &#945;1 gene (2.25 ± 1.07) was overregulated whereas Na/K-ATPase &#946;2 transcripts 0.40 ± 0.30) did not differ among blastocysts produced in vitro from those produced in vivo. Transcripts for gene AQP1 are not present in bovine blastocysts. In vitro culture system does not alter expression of genes AQP3, AQP11 and Na/K-ATPase &#946;2 genes, however, it affects expression of Na/K-ATPase &#945;1.Os objetivos neste trabalho foram identificar e avaliar possíveis diferenças na expressão gênica de transcritos de Aquaporina e ATPases-Na/K presentes em embriões produzidos in vivo e in vitro. Para cada grupo, 15 blastocistos distribuídos em três conjuntos foram utilizados para a extração do RNA, seguida da amplificação e da transcrição reversa. Os DNAs complementares foram submetidos à reação em cadeia da enzima polimerase em tempo real, utilizando-se o gene GAPDH como controle endógeno. Não foi possível identificar transcritos de AQP1. A expressão relativa dos genes AQP3 (1,33 ± 0,78) e AQP11 (2,00 ± 1,42) não foi diferente em blastocistos produzidos in vitro e in vivo. O gene ATPase-Na/K &#945;1 (2,25 ± 1,07) encontrou-se sobrerregulado, enquanto o gene ATPase-Na/K &#946;2 (0,40 ± 0,30) não diferiu entre os blastocistos produzidos in vitro e aqueles produzidos in vivo. Transcritos para o gene AQP1 não estão presentes em blastocistos bovinos. O sistema de cultivo in vitro não influencia a expressão dos genes AQP3, AQP11 e ATPase-Na/K &#946;2, porém altera a expressão do gene ATPase-Na/K &#945;1

Luteal dynamics in goats: morphological and endocrine features

The aim of this study was to establish the morphologic and endocrine characteristics of luteal dynamics in goats. It was used Toggenburg female goats that showed natural estrus in a 48-hour interval. After estrus, ultrasonographic evaluations of the ovaries were daily performed during 21 days using a portable device (5MHz probe). Blood sample was collected for plasma progresterone (P4) determination. Corpora lutea were detected for the first time on day 5 and progressively increased in size until D9 (1.26 ± 0.08 cm²), with no variation on subsequent days. In females with one ovulation, the first visualization of the corpora lutea was earlier than in those with multiple ovulation (4.54 ± 0.18 vs 5.74 ± 0.25 days). At the moment of the first visualization, luteal area was smaller in animals with single ovulation. Plasma P4 concentration progressively increased until day 9 and it did not show significant increase until luteolysis, characterized by a sharp decrease in P4 concentration, reaching values below 1 ng/mL in 24 hours. The luteal area slowly and gradually decreased in size. It was observed a significant positive correlation between P4 concentration and area during luteogenesis and luteolysis (r = 0.63 and r = 0.50, respectively). When corpus luteum reached its maximum size (D9), female with more than one corpora lutea, with a greater luteal tissue area, did not show P4 concentration higher than those with one ovulation (5.92 ± 0.59 vs 7.04 ± 0.79 ng/mL). These results show that luteal dynamics in Toggenbur goats follow a similar pattern to those observed in other goat breeds and luteal tissue growth was positively correlated with corpora lutea functionality.Objetivou-se neste estudo estabelecer as características morfológicas e endócrinas da dinâmica luteal em cabras. Foram utilizadas fêmeas da raça Toggenburg que manifestaram estro natural em um intervalo de 48 horas. Após o estro, foram realizadas avaliações ultrassonográficas diárias dos ovários durante 21 dias, utilizando-se um aparelho portátil (5 MHz). Amostras de sangue foram coletadas para dosagem de progesterona (P4) no plasma. Os corpos lúteos foram detectados pela primeira vez no D5 e aumentaram progressivamente de tamanho até o D9 (1,26 ± 0,08 cm²), não havendo variação nos dias subsequentes. Nas fêmeas com uma ovulação, a primeira visualização do corpo lúteo foi mais precoce que naquelas com ovulação múltipla (4,54 ± 0,18 vs 5,74 ± 0,25 dias). No momento da primeira visualização, a área luteal foi menor nos animais com uma ovulação. A concentração plasmática de P4 aumentou progressivamente até o D9 e não apresentou aumento significativo até o momento da luteólise, caracterizada por uma acentuada queda da concentração de P4, atingindo valores inferiores a 1 ng/mL em um intervalo de 24 horas. A área luteal diminuiu de forma lenta e gradual. Foi observada uma correlação positiva significativa entre a área e a concentração de P4 durante a lutegêonese e a luteólise (r = 0,63 e r = 0,50; respectivamente). No dia em que o corpo lúteo atinge sua área máxima (D9), as fêmeas com mais de um corpo lúteo, com maior área de tecido luteal, não apresentaram concentração de P4 superior à daquelas com uma ovulação (5,92 ± 0,59 vs 7,04 ± 0,79 ng/mL). Esses resultados indicam que a dinâmica luteal em caprinos da raça Toggenburg segue padrões semelhantes aos observados em outras raças e em outras espécies e que o crescimento de tecido luteal refletiu positivamente na funcionalidade do corpo lúteo