Gonadotrophic, prolactin, corticosterone, and gonadal hormones levels over 15 months in Giant Amazon River Turtles - Podocnemis expansa (Schweigger, 1812) (Testudines: Podocnemididae), in captive conditions / Gonadotrofinas, prolactina, corticosterona, e as hormonas sexuais durante 15 meses de Tartarugas da Amazônia - Podocnemis expansa (Schweigger, 1812) (Testudines: Podocnemididae), em condições de cativeiro

Abstract In order to achieve successful captive breeding the Podocnemis expansa, it is necessary to study their reproductive endocrinology. The purpose of this research was to evaluate and characterize plasma concentrations in gonadotrophic, gonadic, corticosterone and prolactin hormones from Giant Amazon Turtles under captive conditions. Blood samples were collected over a 15 month period. The samples were assayed by the use of radioimmunoassay, prolactin, corticosterone, LH, FSH, testosterone, 17β-estradiol and progesterone. We verified significant seasonal pattern increase in 17β-estradiol levels and decrease in progesterone levels in the course of a year, which indicates vitellogenesis. This is related to normal ovarian cycles and possibly to the functional integrity of the hypothalamus-pituitary-gonad axis of captive females. There were negative correlations between testosterone and corticosterone in the male samples, suggestive of stress (management stress) on the reproductive system. The plasma concentrations of gonadotrophic, gonadic, prolactin and corticosterone hormones may be used as a reference for further research and possible therapeutic approaches. The data collected during this research are unprecedented for this species and may serve as a reference for future research regarding the reproductive cycle of this turtle, also allowing reproductive management while in captivity. Information about these hormones must be gathered from wild populations during different periods of the year for better clarification of the reproductive physiology of this species.

Resumo Com o objetivo de obter reprodução em cativeiro de Podocnemis expansa, é necessário reunir o conhecimento a respeito de sua endocrinologia reprodutiva. O objetivo deste trabalho foi avaliar e caracterizar as concentrações plasmáticas de hormônios gonadotróficos, gonadais, corticosterona e prolactina em Tartarugas da Amazônia em condições de cativeiro. Amostras de sangue foram coletadas durante 15 meses. As amostras foram ensaiadas pelo uso de um radioimunoensáio, prolactina, corticosterona, LH, FSH, testosterona, 17β-estradiol e progesterona. Verificou-se aumento de padrão sazonal significativo nos níveis de 17β-estradiol e diminuição dos níveis de progesterona ao longo do ano, o que indica o recrutamento folicular. Isto está relacionado com ciclos ovarianos normais e possivelmente para a integridade funcional do eixo hipotálamo-hipófise-gônadas de fêmeas em cativeiro. Houve correlação negativa entre testosterona e corticosterona nas amostras do sexo masculino, sugestivos de efeito do estresse de manejo sobre o sistema reprodutivo. As concentrações plasmáticas de hormônios gonadotrofinas, gonadais, prolactina e hormônios corticosterona pode ser usado como referência para futuras pesquisas e possíveis abordagens terapêuticas. Os dados médios coletados durante a pesquisa são inéditos para a espécie e pode servir como referência para futuras pesquisas sobre o sistema reprodutivo da tartaruga, também permitindo manejo reprodutivo em cativeiro. Informações sobre esses hormônios devem ser recolhidas a partir de natureza selvagem em diferentes períodos do ano para melhor esclarecimento da fisiologia da reprodução desta espécie.

Gonadotrophic, prolactin, corticosterone, and gonadal hormones levels over 15 months in Giant Amazon River Turtles - Podocnemis expansa (Schweigger, 1812) (Testudines: Podocnemididae), in captive conditions.

In order to achieve successful captive breeding the Podocnemis expansa, it is necessary to study their reproductive endocrinology. The purpose of this research was to evaluate and characterize plasma concentrations in gonadotrophic, gonadic, corticosterone and prolactin hormones from Giant Amazon Turtles under captive conditions. Blood samples were collected over a 15 month period. The samples were assayed by the use of radioimmunoassay, prolactin, corticosterone, LH, FSH, testosterone, 17ß-estradiol and progesterone. We verified significant seasonal pattern increase in 17ß-estradiol levels and decrease in progesterone levels in the course of a year, which indicates vitellogenesis. This is related to normal ovarian cycles and possibly to the functional integrity of the hypothalamus-pituitary-gonad axis of captive females. There were negative correlations between testosterone and corticosterone in the male samples, suggestive of stress (management stress) on the reproductive system. The plasma concentrations of gonadotrophic, gonadic, prolactin and corticosterone hormones may be used as a reference for further research and possible therapeutic approaches. The data collected during this research are unprecedented for this species and may serve as a reference for future research regarding the reproductive cycle of this turtle, also allowing reproductive management while in captivity. Information about these hormones must be gathered from wild populations during different periods of the year for better clarification of the reproductive physiology of this species.

Aspects of the Macroscopic Testicular and Epididymal Morphology in the Greater Rhea, Rhea Americana (Linneaus - 1758) Birds.

The purpose of this research was to study the macroscopic testicular and epididymal morphology of the greater rhea. The testicles of 54 greater rhea bred in captivity were utilized. The samples were collected November 2005 (n = 14), December 2006 (n = 20) and May 2007 (n = 20). During commercial slaughter, the testicles and epididymides were collected and their following morphometric parameters were immediately measured: length, width, thickness, circumference, volume, weight of the parenchyma and the tunica albuginea, also aspects such as shape, cavity implantation, relationship with other organs and vascularization. The testicles presented cylindrical shape, with a thin, dense and transparent tunica albuginea, and the vascularization was accomplished by the testicular artery that ramifies from the cranial rectal artery. In the samples from December 2006 and May 2007, the media from the macroscopic measures of the right testicles were volume 58.7 and 14.7 ml, length 9.87 and 3.5 cm, width 2.4 and 0.6 cm, thickness 2.4 and 0.5 cm, circumference 8.0 and 2.3 cm, parenchyma weight 27.6 and 6.1 g and tunica albuginea weight 1.0 and 0.3 g, P < 0.05, respectively. The epididymides, the media from macroscopic measures December 2006 and May 2007 were volume 7.7 and 3.0 ml, length 5.8 and 1.3 cm, width 0.7 and 0.3 cm, thickness 0.6 and 0.3 cm, circumference 2.5 and 1.2 cm, tissue weight 6.4 and 2.8 g and capsule weight 0.4 and 0.1 g, P < 0.05, respectively. Some measures from the right testicle and epididymis were superior to measures taken from the left ones (P < 0.05), but these were not characterizing asymmetry. The morphometric parameters observed during November 2005 remained on an intermediate situation (P < 0.05); however, they were quantitatively closer to the means of December 2006, which may characterize it as a potential transition period between repose and sexual activity. Morphologically, the testicles and epididymides of greater rhea have common points with other researched birds; however, differences were observed. The testicles and epididymides of the Rhea americana are influenced by the environment, presenting reproductive activity season (November-December) during late spring, early summer and sexual repose season (May) during autumn-winter. The morphometric testicular and epididymal measurements were introduced. The morphometric parameters of testicles and epididymides exhibited differences between winter and spring-summer that could be established like sexual activity season.

Detection of bovine herpesvirus 1 and 5 in semen from Brazilian bulls.

Bovine herpesvirus 1 (BoHV-1) and 5 (BoHV-5) are important pathogens of the respiratory and genital tract of cattle and may also affect the central nervous system and cause meningoencephalitis. Both virus types are estimated to be widely distributed in Southern Brazil. In the present study, BoHV-1 and/or BoHV-5 DNA were detected in bovine semen samples from two states of Brazil by two species-specific nested polymerase chain reactions (nPCRs). These nPCRs were used to assay 53 samples of fresh semen and 23 samples of frozen semen from breeding bulls. Viral DNA was detected in all 76 semen samples: all were positive for BoHV-5, whereas 34 of these were positive for BoHV-1 as well. Moreover, in five fresh and in 13 frozen semen samples-of a total number of 40 samples suitable for virus isolation-infectious BoHV-1 and/or BoHV-5 virus were detected. In conclusion, that both BoHV-1 and BoHV-5 were detected in bovine semen in Brazil highlighted the importance of examining bull semen in search for both agents to reduce the risk of transmitting these viruses.

Sperm morphology of beef bulls evaluated by two different methods.

The objectives of this study were to compare two different methods of evaluating bull sperm morphology, bright-field (BF) microscopy of eosin-nigrosin (EN) stained dry-mount semen smears and differential interference phase contrast (DIC) microscopy of wet-mount semen 'fixed' in isotonic formal saline, both at 1000x. Ejaculates (n=72) were evaluated, representing both pre- and post-breeding season ejaculates collected from 40 2-yr-old beef bulls via electro-ejaculation. For both methods, 200 sperm were counted in random fields with defects categorized as major (MAD) and minor (MID). Sperm abnormalities were also placed into two other categories: those considered to be most influenced by process (wet or dry, METHDEF) and those with depictions that could be influenced by optics (BF or DIC, OPTIDEF). Differences (P<0.05) occurred between DIC and BF methods respectively: MAD 23.3/16.1, MID 7.6/13.4, acrosome 3.8/1.1, midpiece 9.2/11.7, tail 2.0/4.7, droplets 8.3/4.2, METHDEF 14.2/21.4 and OPTIDEF 13.0/5.5, but not (P>0.05) in percent normal sperm 69.1/70.4 or sperm head defects 7.5/8.3. Acrosome, tail and droplet defects were observed in 98.2/80.5, 86.1/100 and 98.2/94.4 percent of bulls for DIC and BF, respectively (P<0.05). As percent normal sperm did not differ between methods, bright-field microscopy assessment of EN preparations was considered to be a satisfactory method to categorize breeding soundness of bulls. However, DIC was more effective in visualizing major defects, while BF (which included stained smear preparation) was considered to cause more minor defects. Thus DIC was considered to be the preferred method of semen assessment for accurate assessment of sperm morphology in bulls.

Puberdade em touros Nelore criados em pasto no Brasil: características corporais, testiculares e seminais e de índice de capacidade andrológica por pontos / Puberty in Nellore bulls raised at pasture in Brazil: body, testicular and seminal characteristics and breeding soundness evaluation

Foram utilizados 23 touros da raça Nelore entre os 10 e 20 meses de idade, para caracterizar o desenvolvimento puberal. Os animais foram criados em condições extensivas com alimentação em pasto e suplementação mineral. A cada duas ou quatro semanas foram realizadas colheitas de dados que incluíram medidas de peso corporal, circunferência torácica, comprimento e largura testicular e circunferência escrotal. Foram, também, colhidos ejaculados pela eletroejaculação e avaliados os aspectos físicos e morfológicos. No momento da colheita de sêmen foram aferidas as porcentagens de desprendimento entre pênis e prepúcio e determinadas as idades médias ao desprendimento total (IDPPRE). Foram determinadas as idades médias ao aparecimento dos primeiros espermatozóides (ISEM1) e dos primeiros espermatozóides móveis (ISEM2) no ejaculado, e a puberdade seminal (IDPUB). Estabeleceram-se os índices de capacidade andrológica por pontos (ICAP). Os touros Nelore apresentaram idades médias ISEM1, ISEM2 e IDPUB de 13,1±2,2, 13,6±2,3 e 14,8±1,8 meses, respectivamente, e IDPPRE de 18,1±1,9. Aos 16 meses de idade, o grupo apresentou 91,4 por cento, 82,6 por cento e 73,9 por cento dos animais com ISEM1, ISEM2 e IDPUB manifestada, respectivamente. Observou-se correlação positiva entre idade dos touros e as características de crescimento corporal, testicular, aspectos físicos dos ejaculados e correlação negativa entre a idade dos touros e os defeitos espermáticos. Observou-se correlação negativa entre a idade dos touros e a pontuação para circunferência escrotal no ICAP à puberdade (-0,77; P<0,001). Touros da raça Nelore, criados a pastos, manifestaram a puberdade precocemente antes dos 15 meses de idade. Houve um período de 51 dias desde o aparecimento dos espermatozóides no ejaculado, até a puberdade seminal. A puberdade foi mais precoce nos touros jovens com maiores testículos.

Twenty three 10-months-old Nellore bulls, raised under pasture conditions in Brazil, were used to study puberty. Monthly measurement of scrotal circumference and testicular width and length were recorded. Semen was collected by eletroejaculation and evaluated according to physical and morphological aspects. Penile and prepuce detachment percentages were also evaluated. The ages of the presence of first spermatozoa in the ejaculate (ISEM1), first motile spermatozoa in the ejaculate (ISEM2), seminal puberty (IDPUB) and detachment between penile and prepuce (IDPPRE) were calculated. Scores of breeding soundness were measured. ISEM1, ISEM2, IDPUB and IDPPRE were 13.1±2.2, 13.6±2.3, 14.8±1.8 and 18.1±1.9 months, respectively. At 16 months of age, the animals presented 91.4 percent, 82.6 percent and 73.9 percent with ISEM1, ISEM2 and IDPUB reached, respectively. High positive correlation were observed between age and corporal and testicular growth or seminal physical aspects. Negative correlation was verified between age and spermatic defects. High negative correlation was observed between age and score of scrotal circumference at puberty (-0.7;7 P<0.001). Precocious puberty was observed before 15 months of age. From ISEM1 to IDPUB, 51 days were elapsed. Young bulls with larger testicles reached puberty earlier.