Carlos Antônio de Carvalho Fernandes

Interrelationships among morphology, echotexture, and function of the bovine corpus luteum during the estrous cycle.

It has been suggested that ultrasound image attributes are a potential indicator of physiological and functional status of the corpus luteum (CL) in several species, including cattle. The aims of this study were to evaluate CL morphological, functional and echotextural characteristics, and also to investigate the hypothesis that those attributes are correlated and change similarly throughout an estrous cycle. Ovaries of crossbred (Bos taurus taurus x Bos taurus indicus) heifers were evaluated using ultrasonography daily throughout an interestrus interval using a B-mode, real-time ultrasound machine equipped with a 5 MHz linear-array rectal transducer, during a natural estrous cycle (Experiment 1; n=12) or during a shortened cycle, with luteolysis induction 10d after estrus (Experiment 2; n=6). Blood samples were collected for assay of plasma progesterone concentrations. Corpora lutea areas were measured and daily images of each CL were videotaped and digitized for computer-assisted analysis using custom-developed software. In Experiment 1, area of luteal tissue increased until a maximum value 10d after estrus (P<0.001), followed by a plateau phase, and then a decline beginning 14 d after estrus. Luteal tissue area was highly correlated to plasma progesterone concentrations (r=0.86; P<0.001). When luteolysis was induced in Experiment 2, loss of CL function (decrease in plasma progesterone concentrations to metestrous values) preceded tissue regression by 48 h (24h compared with 72 h; P<0.001). The mean pixel value of ultrasound images did not change in Experiment 1 (P>0.70), but a day effect on this attribute was observed in Experiment 2 (P=0.052). In contrast, mean pixel value was correlated to plasma progesterone concentrations in Experiment 1 (r=-0.63; P<0.05), but not in Experiment 2 (r=-0.28; P>0.10). In regard to CL heterogeneity, defined as the standard deviation of the mean pixel value of the luteal tissue, a time effect was observed following both natural (Experiment 1; P<0.009) and luteolysis-induced (Experiment 2; P<0.05) estrous cycles (P<0.05). Moreover, this variable was correlated with plasma progesterone concentrations (r=-0.71 and -0.58 in Experiments 1 and 2, respectively; P<0.01), indicating that CL images were more heterogeneous during metestrus and after luteolysis (functional regression). In summary, morphological and echotextural attributes were correlated with CL function and underwent similar changes during the estrous cycle. Luteal tissue heterogeneity, assessed by ultrasonography, is considered a potential indicator of CL functional status, because it is correlated to circulating progesterone concentrations.

Luteal dynamics in goats: morphological and endocrine features

Objetivou-se neste estudo estabelecer as caracteristicas morfologicas e endocrinas da dinâmica luteal em cabras. Foram utilizadas femeas da raca Toggenburg que manifestaram estro natural em um intervalo de 48 horas. Apos o estro, foram realizadas avaliacoes ultrassonograficas diarias dos ovarios durante 21 dias, utilizando-se um aparelho portatil (5 MHz). Amostras de sangue foram coletadas para dosagem de progesterona (P4) no plasma. Os corpos luteos foram detectados pela primeira vez no D5 e aumentaram progressivamente de tamanho ate o D9 (1,26 ± 0,08 cm2), nao havendo variacao nos dias subsequentes. Nas femeas com uma ovulacao, a primeira visualizacao do corpo luteo foi mais precoce que naquelas com ovulacao multipla (4,54 ± 0,18 vs 5,74 ± 0,25 dias). No momento da primeira visualizacao, a area luteal foi menor nos animais com uma ovulacao. A concentracao plasmatica de P4 aumentou progressivamente ate o D9 e nao apresentou aumento significativo ate o momento da luteolise, caracterizada por uma acentuada queda da concentracao de P4, atingindo valores inferiores a 1 ng/mL em um intervalo de 24 horas. A area luteal diminuiu de forma lenta e gradual. Foi observada uma correlacao positiva significativa entre a area e a concentracao de P4 durante a lutegeonese e a luteolise (r = 0,63 e r = 0,50; respectivamente). No dia em que o corpo luteo atinge sua area maxima (D9), as femeas com mais de um corpo luteo, com maior area de tecido luteal, nao apresentaram concentracao de P4 superior a daquelas com uma ovulacao (5,92 ± 0,59 vs 7,04 ± 0,79 ng/mL). Esses resultados indicam que a dinâmica luteal em caprinos da raca Toggenburg segue padroes semelhantes aos observados em outras racas e em outras especies e que o crescimento de tecido luteal refletiu positivamente na funcionalidade do corpo luteo.

Testis morphometry and kinetics of spermatogenesis in the feral pig (Sus scrofa)

The feral pig (Sus scrofa sp) also known as Monteiro pig, originated from a domestic pig breed that was introduced into Pantanal region in Brazil in the eighteenth century. Although the feral pig has commercial potential, there are few reports in the literature concerning the reproductive biology of this species. Therefore, the aim of this study was to further describe the feral pig testis parenchyma as well as characterize the stages of the seminiferous epithelium cycle by tubular morphology method, and to evaluate the number of differentiated spermatogonia generations in this species. Eight sexually mature feral pigs were analyzed. Fragments of testes were embedded in plastic resin and used to prepare slides for morphometrical studies. It was concluded that the feral pig has six generations of differentiated spermatogonials (A1, A2, A3, A4, In, B) and that the cellular composition in the eight stages of the seminiferous epithelium cycle of these animals were very similar to those reported in species of suidae and tayssuidae already studied.

Protocolos hormonais para produção in vitro de embriões de zebuínos e taurinos

The objective of this work was to evaluate the effects of hormonal synchronization protocols, associated or not with follicular development stimulation, on the recovery of oocytes and on in vitro production of Bos indicus and B. taurus embryos, in different seasons. Ultrasound-guided follicular aspirations (n=237) were performed without pre-treatment (G1, control group) and after follicular wave synchronization (G2), or after follicular wave synchronization and follicle growth induction (G3). Bos indicus produced more oocytes and embryos than B. taurus (18.7±0.9 vs. 11.9±0.6 oocytes and 4.8±0.3 vs. 2.1±0.2 embryos). On average, oocyte and embryo yields were higher in G3 than in G2, and both were greater than in G1, which lead to a higher conversion of oocytes to embryos in these treatments. The hot or the cold season did not affect the B. indicus outcomes, whereas, in B. taurus, both oocyte recovery and embryo production were higher in the cold season. Follicular wave synchronization improves ovum pick-up and in vitro production of embryos in both cattle subspecies evaluated.

Inovulation of bovine embryos recently collected in receiving treated with rbST in the estrus day

Estudou-se o efeito da administracao de rbST no dia do estro, na taxa de gestacao e concentracao serica de progesterona em femeas bovinas receptoras de embriao. A administracao subcutânea de rbST (500 mg) foi realizada em 67 receptoras, mantendo-se 77 sem administracao de rbST (144 receptoras no total). Os diagnosticos de gestacao foram realizados aos 30 dias apos o estro e as taxas de gestacao diferiram entre as receptoras: 32,5% (25 das 77 sem administracao de rbST) e 65,7% (44 das 67 receptoras tratadas com rbST). As concentracoes sericas de progesterona obtidas nas amostras de sangue coletadas no dia da inovulacao nao diferiram com a administracao de rbST: 2,54 ± 0,19 ng/mL (sem rbST) e 2,27 ± 0,20 ng/mL (com rbST). Esses resultados indicam que a administracao de 500 mg de rbST no dia do estro aumenta a taxa de gestacao, mas nao influencia a concentracao serica de progesterona de receptoras de embrioes recem-colhidos.

Perfil de progesterona e intervalo ao estro de receptoras bovinas sincronizadas com doses reduzidas de cloprostenol

The objective of this research was to compare the effects of different doses of application of sodic cloprostenol (doses equivalent to 50% the conventional), in the intramuscular (IM) and intra-vulvosubmucosal (IVSM) vias on the synchronization rates, interval of application to estrus and decrease of seric progesterone concentrations. One hundred and ninety-nine females, 103 with of previus report estrous and 96 without report of previus estores evaluated by rectal palpation to verify the presence of corpus luteum, were randomly divided into three treatments: 1 - 68 animals (38 with report of previous estrus) received 1 mL of cloprostenol through IVSM; 2 - 66 animals (33 with report of previous estrus) received 1 mL through IM; 3 - 65 animals (32 with report of previous estrus) received 2 mL through IM. It was considered the animals that showed estrus up to 96 hours after cloprostenol application. The seric progesterone concentrations (P4) were analyzed by RIA at 0 and 48 hours after the application of luteolitic drug. No effects of treatments on synchronization rates (72.1, 53.0, and 64.6%, respectively), interval from application to estrus (69.3 ± 15.2, 67.9 ± 16.7, and 68.3 ± 16.9 hours, respectively) and P4 percentage concentration decrease (79; 68 and 83%, respectively) were observed. However, when data of animals from treatments of days 11 to 16 were grouped and compared to those of treatments of days 7 to 10, the synchronization rates differed (76.1% vs 55.5%). Sodic cloprostenol doses that was reduced by 50%, in IM or IVSM vias, showed effect similar to the conventional dose. Animals during days 11 to 16 respond better to a synchronization with cloprostenol than those during days 7 to 10 of diestrus.

Morphology and Morphometry of Seminiferous Tubules in Crioulo Horses

Abstract This study aimed to assess the biometrics of the testes and the morphology of the seminiferous tubules of Crioulo horses. We studied 10 sexually mature stallions (3–6 years of age). After orchiectomy, testes were perfused with Karnovskys solution and then embedded in glycol methacrylate. Testis sections (4 &mgr;m) were cut and stained with toluidine blue and a solution of 1% sodium borate. The histological images were digitized, and the morphometric analysis was performed using ImageJ software. The average weight of the stallions was 377.5 kg, and the average weight of both testicles was 162.9 g. The percentage of testicular parenchyma occupied by the seminiferous tubules and the intertubular tissue was 77.97% ± 6.34% and 22.03% ± 6.34%, respectively. The average tubular diameter was 205.00 ± 36.91 &mgr;m, whereas the average height of the seminiferous epithelium was 70.56 ± 2.82 &mgr;m. Average tubular length per testicle and average tubular length per gram of testicle were 4,085.10 ± 1,170.68 m and 26.09 ± 10.63 m/g, respectively. The characteristics of the eight stages of the seminiferous epithelium cycle were similar to those reported in other horse breeds. We conclude that the morphometry of the seminiferous tubules of Crioulo horse resembles what has been reported in other horse breeds. The volumetric proportion of the seminiferous tubules and the Leydig cells of the Crioulo horse is one of the highest ever reported for stallions. HighlightsThis is the first article describing the morphology of spermatogenesis Crioulo horses.The volumetric proportion of the seminiferous tubules of the Crioulo horse is one of the highest ever reported for stallions.The proportion of the Leydig cells of the Crioulo horse is one of the highest ever reported for stallions.

Testicular Histomorphometric Evaluation of Zebu Bull Breeds

ABSTRACT The objective of this study was to evaluate the quantitative histology and testicular biometrics in zebu bulls of different breeds. Testicular fragments of Nelore (n=10), Polled Nelore (n=6), Gir (n=5), Guzerat (n=5) and Tabapua bulls (n=5) were used. The fragments were perfusion-fixed in Karnovsky solution, embedded in glycol methacrylate and stained with toluidine blue-1% sodium borate. The Nelore animals had a higher tubular volumetric proportion (85.2%) and greater height of the seminiferous epithelium (73.2 µm) than the Gir, Guzerat and Tabapua breeds. The Nelore animals also had a higher volumetric proportion of Leydig cells (5.2%) than the Guzerat and Tabapua breeds. There was no significant difference for any of these parameters between the Nelore and Polled Nelore breeds. The gonadosomatic index, seminiferous tubule diameter, cross-sectional area of the seminiferous tubule and tubule length (total length and length per gram of testicular parenchyma) did not vary among the breeds studied. The morphometric parameters evaluated suggested that the genetic selection applied to the Nelore and Polled Nelore breeds improved the efficiency of spermatogenesis in these breeders. Key words: cattle, testis, volumetric proportion, seminiferous tubule

Testicular echotexture is not a viable method to indirectly evaluate the spermatogenic parameters in Nelore bulls

espanolRESUMEN El objetivo de este estudio fue evaluar la ecotextura testicular de los toros Nelore y correlacionarlo con los parametros de espermatogenesis. Para este proposito, 41 toros de edades de 3-5 anos y con pesos corporales en el intervalo de 510,2 ± 21,61 kg fueron seleccionados para el estudio. Los toros se sometieron a ecografia, utilizando un dispositivo portatil junto con un transductor lineal a una frecuencia de 7,5 MHz. Inmediatamente despues, los animales fueron castrados, y el tejido testicular se trato con Karnovsky fijador. Los fragmentos testiculares se incluyeron en metacrilato de glicol y se tineron con una solucion de borato de sodio-azul de toluidina al 1%. La intensidad media de pixeles en el parenquima testicular se determino para secciones de superficie de 1.600 mm2. Los El area entre los dos testiculos derecho e izquierdo dieron lugar a la intensidad media de los pixeles de 105,22 ± 13,58, 107,95 ± 12,82 y 106,59 ± 11,43, respectivamente. El coeficiente de eficiencia de la mitosis espermatogonial fue 19,74; Indice meiotico fue 2,63, y el rendimiento global del espermatogenesis alcanzo el 52,0. No se observo correlacion (P>0,05) entre ecotextura testicular y cualquiera de los parametros morfometricos medidos. Estos resultados sugieren que ecotextura testicular no es un metodo viable para el analisis indirecto de la poblacion celular en el epitelio seminifero, el rendimiento de la espermatogenesis intrinseco, o el indice de celulas de Sertoli en toros Nelore. EnglishABSTRACT The objective of this study was to evaluate the testicular echotexture of Nelore bulls and to correlate it with spermatogenic parameters. Forty one bulls aged 3-5 years, with body weight of 510.2 ± 21.61 kg were selected for the study. The animals were subjected to ultrasonography, using a portable device coupled with a linear transducer at a frequency of 7.5 MHz. Immediately afterwards they were castrated and the testicular tissue was treated with Karnovsky fixative. Next, the fragments were embedded in glycol methacrylate and stained with toluidine blue-1% sodium borate solution. The average pixel intensity in the testicular parenchyma was determined for 1,600-mm2 surface sections. The right and left testicles and the area between the two testicles resulted in average pixel intensities of 105.22 ± 13.58, 107.95 ± 12.82, and 106.59 ± 11.43, respectively. The efficiency coefficient of spermatogonial mitosis was 19.74; meiotic index was 2.63, and overall yield of spermatogenesis was 52.0. No correlation (P>0.05) was observed between testicular echotexture and any of the measured morphometric parameters. These results suggest that testicular echotexture was not a viable method for the indirect analysis of cellular population in the seminiferous epithelium, intrinsic spermatogenic performance, or the Sertoli cell index in Nelore bulls.

Acurácia da ultrassonografia e da avaliação comportamental na determinação das características funcionais de estruturas ovarianas císticas

The objective of this work was to evaluate the accuracy of ultrasound and symptomatology in determining functional features of ovarian cystic structures. In 51 Girolando cows, without corpus luteum, the following were evaluated: presence or absence of luteinized tissue on the follicle wall; serum concentrations of progesterone (P4); and animal clinical signals (anestrus or nymphomania). P4 plasma concentrations were considered as the gold standard. Ultrasound evaluation was an accurate (82.4%) method to diagnose the type of follicular cyst. Anestrus is related to the presence of luteinized cysts and high P4 levels. Non-luteinized cysts are often found in animals with low P4, which exhibit anestrus or nymphomaniac behavior.