Biometrical aspects of the capybara’s (Hydrochoerus hydrochaeris) body and intestines with emphasis on cecal development

The rodent capybara (Hydrochoerus hydrochaeris) has become a new protein source for the population, but it needs studies regarding its anatomy, mainly on its digestive physiology, since this aspect has a direct influence on improvements to species production. Studies have shown that the caecum is the largest of intestinal organs in this rodent and it presents the greatest capacity in relation to the other animals. For the purpose of the current study, 15 animals were divided into two groups: G1, consisting of 4 animals less than 12 months of age, and G2 consisting of 11 animals over 12 months of age. The following biometrical parameters were obtained: body weight, crown-rump length, thoracic perimeter, lengths of the small intestine, large intestine and caecum, volume of the caecum and the average weight of the eyes’ bulb lenses that determined the age of the animals. The measures of the capybara’s caecum were correlated with different morphologic and biometric aspects of this animal in different phases of growth, from birth to the adult stage. Most parameters revealed an increase when comparing the group of young animals with the adults ones, with the exception of the caecum volume that only presented significant growth within the first group. Positive correlation was only identified between the parameters for weight and CCR. It was verified that body growth persists after puberty, with the intestinal development occurring at low intensity in comparison with the young animals

Corporal and testicular biometry in wild boar from birth to 12 months of age

The aim of this tudy was to evaluate corporal and testicular development in wild boars (Sus scrofa scrofa) from birth to 12 months of age, evaluating body weight, biometric testicular parameters, and gonadosomatic index. Thirty-nine male wild boars from a commercial farm licensed by IBAMA were used in the study. The animals were weighed and assigned to 13 experimental groups. The testes were recovered through unilateral orchiectomy, weighed on an analytical balance and measured for length, width and thickness. Body weight and testicular measures increased with the age, up to 12 months, and were more accelerated in the first and ninth months. Initially the testicular growth pattern, between zero and nine months, followed the body growth, and the gonadosomatic index varied from 0.07 to 0.09%. Between 9 and 11 months, the testicular growth was superior to the body growth, and the gonadosomatic index varied from 0.09 to 0.16%. Finally, after 11 months of age, testicular and body growth had a similar behavior. In conclusion, body weight, testicular biometry, and gonadosomatic index development accelerated in the ninth month

Inovulação de embriões bovinos recém-colhidos em receptoras tratadas com rbST no dia do estro

Estudou-se o efeito da administração de rbST no dia do estro, na taxa de gestação e concentração sérica de progesterona em fêmeas bovinas receptoras de embrião. A administração subcutânea de rbST (500 mg) foi realizada em 67 receptoras, mantendo-se 77 sem administração de rbST (144 receptoras no total). Os diagnósticos de gestação foram realizados aos 30 dias após o estro e as taxas de gestação diferiram entre as receptoras: 32,5% (25 das 77 sem administração de rbST) e 65,7% (44 das 67 receptoras tratadas com rbST). As concentrações séricas de progesterona obtidas nas amostras de sangue coletadas no dia da inovulação não diferiram com a administração de rbST: 2,54 ± 0,19 ng/mL (sem rbST) e 2,27 ± 0,20 ng/mL (com rbST). Esses resultados indicam que a administração de 500 mg de rbST no dia do estro aumenta a taxa de gestação, mas não influencia a concentração sérica de progesterona de receptoras de embriões recém-colhidos

The spermatogenic process of the common vampire bat Desmodus rotundus under a histomorphometric view.

Among all bat species, Desmodus rotundus stands out as one of the most intriguing due to its exclusively haematophagous feeding habits. However, little is known about their spermatogenic cycle. This study aimed at describing the spermatogenic process of common vampire bats through testicular histomorphometric characterization of adult specimens, spermatogenic production indexes, description of stages of the seminiferous epithelium cycle and estimative of the spermatogenic process duration. Morphometrical and immunohistochemical analyzes for bromodeoxiuridine were conducted under light microscopy and ultrastructural analyzes were performed under transmission electron microscopy. Vampire bats showed higher investment in gonadal tissue (gonadosomatic index of 0.54%) and in seminiferous tubules (tubulesomatic index of 0.49%) when compared to larger mammals. They also showed a high tubular length per gram of testis (34.70 m). Approximately half of the intertubular compartment was found to be comprised by Leydig cells (51.20%), and an average of 23.77x106 of these cells was found per gram of testis. The germline cells showed 16.93% of mitotic index and 2.51% of meiotic index. The overall yield of spermatogenesis was 60% and the testicular spermatic reserve was 71.44x107 spermatozoa per gram of testis. With a total spermatogenesis duration estimated at 37.02 days, vampire bats showed a daily sperm production of 86.80x106 gametes per gram of testis. These findings demonstrate a high sperm production, which is commonly observed in species with promiscuous mating system

Maturação sexual e parâmetros reprodutivos em touros da raça Nelore criados em sistema extensivo

Objetivou-se verificar o estágio de maturidade sexual, a ocorrência do formato testicular e a relação entre características reprodutivas de tourinhos da raça Nelore. Foram utilizados 5.903 touros com média de 21 meses de idade submetidos a exame andrológico entre os anos de 1999 e 2003. Na ocasião do exame, foram registradas as seguintes características: perímetro escrotal (31,99 ± 2,23 cm), comprimentos testiculares esquerdo (11,21 ± 0,98 cm) e direito (11,26 ± 0,97 cm), larguras testiculares esquerda (5,92 ± 0,44 cm) e direita (5,97 ± 0,46 cm), formato testicular, variando de 1 a 5 (1,72 ± 0,46), volume testicular (632,21 ± 132,72 cm³), motilidade espermática progressiva retilínea (69,56 ± 12,31%), vigor espermático (2,87 ± 0,61) e morfologia espermática, com defeitos totais (22,19 ± 11,13%) e maiores (15,86 ± 10,45%) dos espermatozoides. As freqüências dos formatos testiculares foram longo (30,80%), longo-moderado (66,19%), longo-oval (2,49%), oval-esférico (0,02%) e esférico (0,04%). As correlações entre perímetro escrotal e características reprodutivas foram positivas. O perímetro escrotal é uma ótima característica para seleção de touros jovens da raça Nelore, que, na maioria (78,33%), apresentam-se sexualmente maturos aos 21 meses de idade

Taxa de prenhez e concentração sérica de progesterona em novilhas receptoras de embrião tratadas com somatotropina recombinante bovina (RBST)

O objetivo deste trabalho foi avaliar o efeito da aplicação de somatotropina recombinante bovina (rbST) sobre a taxa de prenhez e a concentração sérica de progesterona (P 4 ) em novilhas receptoras de embrião. Foram selecionadas 52 novilhas como receptoras, distribuídas aleatoriamente em dois grupos (G1 e G2), sendo o G1 composto por 22 novilhas que não receberam rbST (controle), e o G2 por 30 novilhas que receberam 250 mg de rbST, por via subcutânea, na fossa ísqueo-retal, durante o estro. As novilhas de ambos grupos foram inovuladas entre o sexto e oitavo dia do ciclo estral com embriões recém-coletados. No momento da transferência dos embriões, colheu-se sangue da veia ou artéria coccígea, para análise da concentração sérica de P 4 , pela técnica de radioimunoensaio. A taxa de prenhez foi determinada por exame ultra-sonográfico realizado no 28o dia após a detecção do estro das receptoras. Foram observadas 14 novilhas gestantes (46,6%) no G2 e 11 novilhas gestantes (50,0%) no G1. A rbST não afetou a taxa de gestação das novilhas receptoras (P>0,05). A concentração média de P 4 no dia da inovulação dos embriões foi de 1,71±0,74 ng/mL para os animais de G1 (n=22) e de 1,48±0,72 ng/mL para os de G2 (n=27), não havendo diferença (P>0,05). Concluiu-se que a aplicação de 250 mg de rbST, durante o estro, em novilhas receptoras de embrião não afetou a concentração sérica de P 4 entre o sexto e oitavo dia, nem a taxa de prenhez no 28o dia após o estro.The aim of this work was to evaluate the effects of recombinant bovine somatotropin (rbST) on pregnancy rate and progesterone (P4) serum concentration in embryo recipient heifers. Fifty two heifers were selected as recipients and randomly allocated into two groups, (G1 and G2), where the G1 was composed by 22 heifers which were not injected with rbST (control), and the G2 by 30 heifers, which were treated with a single subcutaneous injection of 250 mg of rbST, applied at detected estrus. Heifers from both treatments received fresh embryos, from day six to eight after the detected estrus. At the moment of embryo transfer, blood samples were collected from the coccygeal vein or artery for serum P4 analysis using the radioimmunoassay technique. The pregnancy rate was established by ultrasound exam performed twenty eight day after detected estrus of the receptors. No significant difference (P>0.05) was observed in the pregnancy rate between G1 (50%) and G2 (46.6%) treated heifers, or in the P4 concentration, with mean values of 1.71±0.74 ng/mL, and 1.48±0.72 ng/mL for G1 (n=22) and G2 (n=27) treated animals, respectively. In conclusion, the application of 250 mg rbST, at detected estrus in heifers, had no effect between days six to eight on P4 serum concentration or on pregnancy rate twenty-eight day after detected estrus

Germ cells and spermatic production indexes in <i>Desmodus rotundus</i>.

<p>Germ cells and spermatic production indexes in <i>Desmodus rotundus</i>.</p