Abstract Lab animals, such as Guinea pigs (Cavia porcellus), are crucial for scientific development, as they play an important role in the development and quality control chain of vaccines and drugs distributed by the Brazilian public health system. Investigating their biological and physiological parameters is fundamental to raise and keep these animals, so the handling of the facilities that hold them can be updated whenever new information comes up, with the well-being of the animals and alignment with the 3 Rs in mind. In the search for understanding reproductive aspects of Guinea pigs, the present study had the main goal of studying puberty by means of estrous cycle analysis in short-haired Guinea pigs. Guinea pigs have a vaginal occlusive membrane that covers the vaginal orifice. Its rupture takes place gradually and naturally, moments before labor and during estrus. The present study followed 42 females as for the presentation of the vaginal occlusive membrane. Once the membranes ruptured spontaneously, a swab was collected to study vaginal cytology. Membrane rupture was observed in 39 females; six females showed membrane rupture with less than 21 days of age (17 to 21 days). Twenty-three females were characterized as being in estrus due to cytology showing a prevalence of anucleated superficial cells. One of these females was younger than 21 days old. The opening of the vaginal occlusive membrane took place most frequently in intervals between 17 and 18 days, and the membrane remained open between one and three consecutive days. It was possible to follow three cycles of membrane opening on six females. The present study showed the need to adapt handling guidelines for C. porcellus kept in research animal facilities. The early age of puberty imposes the need of separate the female daughters from their fathers at 16 days old.

Resumen:El agouti (Dasyprocta sp.) es un roedor histricomorfo encontrado en algunas regiones de América. Es una especie cinegética importante, lo que indica que la caza excesiva es una amenaza para su conservación. Muy poco es lo que se conoce acerca de la biología de los animales silvestres, en relación al conocimiento acumulado sobre los domésticos. Por lo tanto, el estudio sobre la reproducción de los animales silvestres se hace necesario e imprescindible para el manejo y conservación de la especie como recurso natural. En concreto, los estudios relativos a la monitorización hormonal son una herramienta básica para la investigación en biotecnología reproductiva moderna. No hay información sobre los cambios de progesterona durante la preñez de Dasyprocta sp. en comparación con otros histricomorfos. El objetivo de este estudio fue describir el perfil de la progesterona plasmática durante la preñez, y reportar el reinicio del ciclo ovárico después del parto. Para ello, se utilizaron 18 agoutis de rabo negro (Dasyprocta prymnolopha) nacidos en cautiverio. Fueron estudiadas una o más preñeces consecutivas. La copulación fue confirmada por la presencia de espermatozoides observados en examen colpocitológico. Las muestras de sangre se recogieron dos veces por semana, y las concentraciones de progesterona se determinaron en 10 individuos mediante radioinmunoensayo. Se observó el inicio de la actividad ovárica diaria por examen colpocitológico, comenzando en el día séptimo posparto. El período gestacional observado en este estudio fue de 104.04 días (SD= 1.31, rango entre 101-106 días, N= 26), y el intervalo entre los nacimientos fue 126.03 días (SD= 18.40, rango entre 109-184 días). El perfil plasmático de la progesterona durante el embarazo mostró un aumento progresivo de la 1ª a la 5ª semana. Los mayores niveles de progesterona durante este período (6.88 ng / mL, SD= 3.01) se detectaron en la quinta semana. Este valor fue similar (ANOVA de um factor, p > 0.05) al observado en las semanas cuatro y seis, pero fue estadísticamente diferente (ANOVA de um factor, p<0.05) en comparación con las otras semanas. Después de la sexta semana hubo una disminución progresiva en los niveles plasmáticos de progesterona. Los animales mostraron un estro posparto de 12.04 días (SD= 4.29, rango entre 7-24 días, N= 23). Se observó que el 80.95 % (N= 19) de cópulas durante este período fueron fértiles. Este trabajo contribuyó a la comprensión de los cambios dinámicos en los niveles de progesterona durante la preñez del agouti. Sin embargo, se necesitan más estudios para una mejor comprensión de otros cambios biológicos y endocrinos, y en la unidad materna y feto-placentaria del agouti.

Abstract:The agouti (Dasyprocta sp.) is a hystricomorph rodent found in some regions of the Americas. It is an important cynegetic species, which indicates that the overhunting is a threat to their conservation. Very little is known about this wildlife in relation to what already has been studied in domestic animals. Thus, the knowledge on reproduction of wildlife becomes necessary and essential for the management and conservation of these natural resources. Specifically, studies regarding hormonal monitoring are important as a basic tool for research in modern reproductive biotechnology, and currently, there is no information on the progesterone changes during pregnancy of Dasyprocta sp., compared to other hystricomorphs. The aim of this study was to describe the profile of plasmatic progesterone during pregnancy, and report the restart of ovarian cycle in agouti after parturition. For this purpose, 18 black-rumped agoutis (Dasyprocta prymnolopha) born in captivity were used, and one or more consecutive pregnancies were observed. Copulation was confirmed by the presence of spermatozoa observed in the colpocytological examination. Blood samples were collected two times per week, and concentrations of progesterone, assessed in ten agoutis, were determined by radioimmunoassay. The onset of ovarian activity in six females was observed daily by colpocytological examination, starting on the seventh day postpartum. The gestational period observed in this study was 104.04 days (SD = 1.31) (101-106 days) (Number of cases, N = 26), and the interval between births was 126.03 days (SD = 18.40) (109-184 days). The plasmatic profile of progesterone during pregnancy showed a progressive increase from the 1st to the 5th week. The higher progesterone levels over this period (6.88 ng / mL, SD = 3.01) were detected in the 5th week. This value was similar (One-Way ANOVA, p > 0.05) to that observed in the 4th and 6th weeks, but was statistically different (One-Way ANOVA, p < 0.05) when compared to the other weeks. After the 6th week there was a progressive decrease in plasmatic progesterone levels. The animals showed a postpartum estrus of 12.04 days (SD= 4.29) (7-24 days) (N= 23). It was observed that 80.95 % (N= 19) of copulations during this period were fertile. This work contributed to understanding the dynamic changes in the progesterone levels during the pregnancy in agouti. Nevertheless, more studies are needed for a better appreciation of other endocrine and biological changes, in the mother and feto-placental unit of the agouti. Rev. Biol. Trop. 64 (4): 1519-1526. Epub 2016 December 01.

Estudos biológicos são necessários para o manejo da vida silvestre em cativeiro, e o conhecimento da reprodução é um dos aspectos importantes para o aumento da produção. Esta pesquisa teve como objetivo determinar a idade da puberdade do cateto macho. Foram utilizadas amostras testiculares de 15 animais, entre 7 a 16 meses, distribuídos em cinco grupos (G1, G2, G3, G4 e G5). Os testículos aumentaram no peso, comprimento e largura consideravelmente (p < 0,05) do G1 ao G3, enquanto que, a partir deste grupo, o desenvolvimento desse órgão foi mais lento. Houve correlação positiva (p < 0,001) entre os seguintes parâmetros testiculares: peso e comprimento (r = 0,97), peso e largura (r = 0,88), comprimento e largura (r = 0,92). Com relação ao diâmetro tubular, observou-se um aumento (p < 0,05) do G1 ao G4. A quantidade total de células espermatogênicas aumentou significativamente (p < 0,05) até o G3, e se estabilizou a partir deste grupo. Houve correlação positiva entre o peso testicular e o diâmetro tubular (r = 0,99, p < 0,001), bem como o peso testicular e as células espermatogênicas (r = 0,98, p < 0,001). A quantidade de células de Sertoli reduziu significativamente (p < 0,05) do G1, onde se encontravam indiferenciadas como células de suporte, até G5, onde foram observadas juntamente com todas as células da linhagem espermática. Estes resultados demonstraram que as fases do desenvolvimento reprodutivo de catetos podem ser classificadas em: impúbere (G1, 7-8 meses), pré-púbere (G2, 9-10 meses), púbere (G3, 11-12 meses), pós-púbere 1 (G4, 13-14 meses) e pós-púbere 2 (G5, 15-16 meses). Com base na análise histológica, a puberdade dos catetos machos ocorre entre 11 e 12 meses de idade.

Biological studies are necessary for the management of wildlife in captivity, and knowledge of reproduction is one of the important features for increasing production. The objective of the research was to determine the age at which male collared peccaries reach puberty. Testicular samples of 15 animals, aged 7 to 16 months, distributed into five groups (G1, G2, G3, G4 and G5) were used. The testes showed considerably increased weight, length and width (p < 0.05) from G1 to G3, whereas, from this group onward, the development of this organ was slower. There was positive correlation (p < 0.001) between the following testicular parameters: weight and length (r = 0.97), weight and width (r = 0.88), length and width (r = 0.92). Regarding the diameter of seminiferous tubules, an increase was observed (p < 0.05) from G1 to G4. The total number of spermatogenic cells increased significantly (p < 0.05) until G3 and then it stabilized. There was also positive correlation between testis weight and tubular diameter (r = 0.99, p < 0.001), and testis weight and spermatogenic cells (r = 0.98, p < 0.001). The number of Sertoli cells decreased significantly (p < 0.05) from G1, when they were undifferentiated as support cells, to G5, when they occurred together with the complete line of spermatic cells. The results demonstrate that the reproductive development of peccaries can be classified into the following stages: impuberty (G1, 7-8 months); pre-pubertal (G2, 9-10 months); pubertal (G3, 11-12 months); post-pubertal 1 (G4, 13-14 months); and post-pubertal 2 (G5, 15-16 months). Based on the histological analyses, puberty in the male collared peccary was determined to occur between 11 and 12 months of age.

La sustentabilidad y la producción de pecarí de collar (Pecari tajacu) han sido estudiados en los últimos años, sin embargo, más información sobre su reproducción es necesaria para el éxito de los sistemas de crianza . La comprensión de los aspectos relacionados con la foliculogénesis contribuirá con la aplicación de biotécnicas de reproducción, las cuales son útiles en la preservación y la producción de la vida silvestre. El objetivo de este estudio fue obtener datos sobre la población folicular del ovario de pecarí de collar. En relación con la población folicular en el ovario derecho, los valores de los folículos primordiales y primarios fueron similares, pero se observó que había una diferencia significativa (p<0.05) con el secundario. En el ovario izquierdo, la fase folicular presentó diferencias significativas (p<0.05) entre todos los folículos, y en la fase lútea el número medio de folículos primordiales y primarios fueron similares. Ahora bien, con respecto a la población de folículos antrales, en la fase folicular, se observaron diferencias significativas entre los ovarios (p<0.05), y de forma similar en la fase lútea. También se encontraron diferencias significativas en el diámetro medio de los folículos preantrales, oocitos, la capa granulosa y el núcleo del oocito durante las fases del ciclo estral. Asimismo, en los folículos antrales se observó diferencia estadísticamente significativa (p<0.05) en el diámetro folicular. En ambas fases del ciclo estral, se encontró el predominio de folículos primordiales y primarios en desarrollo, por otro lado, los folículos secundarios y los folículos antrales mostraron un alto grado de degeneración. Los resultados aquí presentes son necesarios para el desarrollo de los programas de mejoramiento y conservación.

The sustainability and production of collared peccary (Pecari tajacu) has been studied in the last few years; however, further information on its reproduction is necessary for breeding systems success. Understanding folliculogenesis aspects will contribute to effective reproductive biotechniques, which are useful in the preservation and production of wildlife. The aim of this study was to evaluate the ovarian folliculogenesis in collared peccary. Ovaries from six adult females of collared peccary were obtained through ovariectomy and analyzed. These were fixed in aqueous Bouin’s solution and sectioned into 7μm slices, stained with hematoxilin-eosin and analyzed by light microscopy. The number of pre-antral and antral follicles per ovary was estimated using the Fractionator Method. The follicles, oocytes and oocyte nuclei were measured using an ocular micrometer. Results showed that the length, width, thickness, weight, and the gross anatomy of the right and left ovaries were not significantly different. However, the mean number of corpora lutea was different between the phases of the estrous cycle (p<0.05), with the highest mean in the luteal phase. Primordial follicles were found in the cortex; the oocytes were enveloped by a single layer of flattened follicular cells. In the primary follicles, proliferation of the follicular cells gave rise to cuboidal cells (granulosa cells). The secondary follicle was characterized by two or more concentric layers of cuboidal cells (granulosa), beginning of antrum formation, and the presence of pellucid zone and theca cells. Antral follicles were characterized by a central cavity (antrum), the presence of cumulus oophorus and theca layers (interna and externa). In the right ovary, the values of the primordial and primary follicles were similar, but significantly different from the secondary ones (p<0.05). In the left ovary, significant differences were observed between all follicles in the follicular phase (p<0.05); the mean number of primordial and primary follicles was similar in the luteal phase. The mean number of pre-antral follicles and antral follicles in the follicular phase was higher in the left ovary (p<0.05). The mean number of antral follicles in the luteal phase was similar in both ovaries. We also found significant differences in mean diameter of preantral follicles, oocyte, granulosa layer and oocyte nucleus during the estrous cycle. In the antral follicles a significant difference was observed only in follicular diameter (p<0.05). The predominance of active primordial and primary follicles was found in both phases; otherwise the secondary follicles and antral follicles showed a high degree of degeneration. The results obtained in the present work will strengthen the development of biotechnology programs to improve the productive potential and conservation of the collared peccary.

El conocimiento de los procesos reproductivos de especies de importancia económica local son indispensables para apoyar su producción en cautiverio y garantizar su manejo sostenible. El objetivo del presente trabajo fue evaluar los niveles hormonales de progesterona y 17β-estradiol durante el ciclo estral en agutí (Dasyprocta prymnolopha). La recolección de sangre se realizó dos veces por semana, sin sedación. Las hormonas fueron analizadas por radioinmunoanálisis. Los niveles de progesterona fueron los siguientes: proestro 0.78+0.39ng/ml, estro 2.83+2.34ng/ml, metaestro 1.49+1.24ng/ml y diestro 3.71+1.48ng/ml. En el estro se observó un aumento de los niveles de progesterona durante un periodo de 24h. Los niveles de 17 β-estradiol fueron los siguientes: proestro 2 030.98+961.00pg/ml, estro 1 910.56+650.54pg/ml, metaesto 1 724.83+767.28pg/ml y diestro 1 939.94+725.29pg/ ml. Los resultados encontrados sugieren que los niveles plasmáticos de progesterona durante el ciclo estral en agutí siguen un patrón de aumento, estabilización y diminución, tal como en los mamíferos domésticos. Agutí tienen dos etapas de desarrollo folicular, puesto que se observaron dos altos valores de 17β-estradiol, el primero en el metaestro y el segundo durante el proestro. La ovulación espontánea ocurre posiblemente después del aumento de la progesterona, indicando que esta hormona posiblemente está asociada con el proceso ovulatorio. Es necesario desarrollar un estudio más detallado para mejorar la comprensión del papel de la progesterona en la ovulación. Algunos estudios de la participación de la progesterona en la ruptura folicular se pueden realizar utilizando inhibidores de la biosíntesis de esteroides y observar el efecto de esta hormona sobre la actividad de las enzimas proteolíticas en la pared folicular.

Plasma concentration of progesterone and 17β-estradiol of black-rumped agouti (Dasyprocta prymnolopha) during the estrous cycle. The agouti is a game animal that have been raised in captivity for conservation and sustainability purposes. However, the management of wild animals in an intensive breeding system requires an assertive knowledge of its reproductive parameters, one of the most important features for production improvement. Besides, little information is available regarding changes in reproductive hormone profiles in agouti. The objective of this study was to evaluate the hormonal profile of progesterone and 17β-estradiol during the estrous cycle of the agouti (Dasyprocta prymnolopha). The hormones were analyzed by radioimmunoassay. Blood samples were collected without sedation twice a week. The concentrations of progesterone were as follows: proestrus 0.78+0.39ng/ml, estrus 2.83+2.34ng/ml, metestrus 1.49+1.24ng/ml, diestrus 3.71+1.48ng/ml. In the estrous phase, an increase in the progesterone level was observed during a period of 24h. The average 17 β-estradiol levels were as follows: proestrus 2 030.98+961.00pg/ml, estrus 1 910.56+650.54pg/ml, metestrus 1 724.83+767.28pg/ml, diestrus 1 939.94+725.29pg/ml. The current results suggest that the progesterone plasma concentration during the estrous cycle in the agouti has a similar increasing, stabilizing and decreasing pattern, as in domestic mammals. Agoutis have two phases of follicular development, as two periods of 17β-estradiol peaks were observed, the first one in the metestrus and the second during the proestrus. Spontaneous ovulation seems to occur after the progesterone peak, possibly indicating that this hormone is associated with the ovulatory process. A more detailed investigation is needed for better understanding of how progesterone influences ovulation. Studies on the involvement of progesterone in follicular rupture can be carried out, using steroid biosynthesis inhibitors and observing the effect of this hormone on ovarian activity of proteolytic enzymes in the follicular wall. Rev. Biol. Trop. 59 (1): 29-35. Epub 2011 March 01.

Este trabalho teve por objetivo estudar o ciclo estral do cateto, aplicando a colpocitologia como método diagnóstico. As amostras da citologia vaginal foram coletadas em dez fêmeas adultas, durante três vezes na semana, por seis meses. Verificou-se que a duração média do ciclo estral para esta espécie foi de 28,45 ± 5,45 dias. Observou-se diferença estatística (p<0,01) em relação à frequência dos diferentes tipos celulares na mesma fase do ciclo estral. No proestro foi verificado o aumento de células intermediárias e superficiais. A fase de estro caracterizou-se pela elevação significativa de células superficiais em relação aos demais tipos celulares e pela ausência de leucócitos. Durante este período, a genitália externa estava hiperêmica, edemaciada e com muco. No metaestro houve um decréscimo de células superficiais, quando comparado com o proestro e com o estro, e uma elevação significativa de células intermediárias, presença de leucócitos, de células de metaestro e de foam. Na fase de diestro, houve um aumento de células intermediárias, e um decréscimo no número de leucócitos. Conclui-se que, por meio da colpocitologia, é possível diferenciar as fases do ciclo estral em catetos.

The main objective of this work was to study the estrous cycle of collared peccary by vaginal cytology. Samples were collected in 10 adult females, three times a week, for six months. The estrous cycle period for this specie was 28.45 ± 5.45 days. We observed a significant difference (p<0.01) between the cell types in the same phase of the oestrous cycle. During the proestrus phase, the exfoliative cytology arrangement showed high frequency of intermediate and superficial cells. The estrus phase had elevated rates of superficial cells, when compared to the other types, and an absence of leukocytes. During this phase, the external genitalia were reddish, tumescent; and the cervical mucus was evident. In the metaestrus phase, we observed a decrease of superficial cells, as well as the highest indices of intermediate cells, an increase of leukocytes and the presence of metestrus and foam cells. In the diestrus phase, the intermediate cells increased and leukocytes decreased. In conclusion, the present study suggests that it is possible to differentiate the phase of estrous cycle by vaginal cytology.

Estudos relacionados à obtenção e avaliação de sêmen de Tayassu tajacu são escassos, sendo necessárias pesquisas a respeito. Os objetivos do estudo foram avaliar a biometria testicular de caititus adultos cativos, testar a eficiência da eletroejaculação para obtenção de sêmen e avaliar suas características seminais ao longo do ano. Procedeu-se à eletroejaculação em oito animais adultos e as amostras de sêmen colhidas foram avaliadas quanto às características físicas e morfológicas. Os animais tinham testículo esquerdo com 3,8 ± 0,4 cm X 2,6 ± 0,3 cm e 2,3 ± 0,2 de consistência, e testículo direito com 3,8 ± 0,5 cm X 2,7 ± 0,3 cm e 2,3 ± 0,2 de consistência. A taxa de sucesso nas colheitas foi de 75,21%. O sêmen possuiu: volume 0,81 ± 0,86 mL, concentração 137,44 ± 153 x 106 sptz mL-1, pH 7,92 ± 0,73, motilidade 52,66 ± 28,79%, vigor 2,2 ± 0,8, integridade de membrana plasmática 55,84 ± 28,55%, defeitos maiores 22,87 ± 12,93%, defeitos menores 9,11 ± 5,88% e defeitos totais 31,52 ± 13,81%. Os animais apresentaram simetria testicular, a eletroejaculação se mostrou eficiente para a obtenção de ejaculados em caititus e as flutuações observadas na produção seminal não foram suficientes para caracterizá-los como animais de reprodução sazonal.

Research development in semen collection and sperm evaluation of Tayassu tajacu are necessary. The aims of this research were to evaluate testicular biometry of captive collared peccaries, test electroejaculation for semen collection and evaluate seminal characteristics during the year. Eight animals were submitted to electroejaculation and semen samples were evaluated according their physical and morphological characteristics. Left testicles measured 3.8 ± 0.4 cm X 2.6 ± 0.3 cm and presented 2.3 ± 0.2 of consistence, while right testicles were 3.8 ± 0.5 cm X 2.7 ± 0.3 cm and presented 2.3 ± 0.2 of consistence. Success rate on semen collections achieved 75.21%. Semen presented 0.81 ± 0.86 mL (volume), 137.44 ± 153 x 106 sptz mL-1 (sperm concentration), 7.92 ± 0.73 (pH), 52.66 ± 28.79% (sperm motility), 2.2 ± 0.8 (vigour), 55.84 ± 28.55% (plasmatic membrane integrity), 22.87 ± 12.93% (primary defects), 9.11 ± 5.88% (secondary defects) and 31.52 ± 13.81% (overall defects). Seminal characteristics showed no expressive variation along the year. Testicular symmetry was observed, electroejaculation was an efficient method to semen collection and slight mensal oscillations of seminal quality were not enough to characterize collared peccaries as seasonal reproductive animals.

En los bosques tropicales, el consumo de carne silvestre representa una opción o la única fuente de proteínas para algunas poblaciones humanas. Este estudio analizó el comercio ilegal de carne de animales silvestres con fines alimenticios en un mercado de la Amazonia brasileña. El comercio de carne fue observado todo el año (2005), a través de entrevistas a los vendedores y consumidores, para la valoración del perfil socioeconómico de los comerciantes, determinar las principales especies y los subproductos vendidos, el origen geográfico, valor comercial, frecuencia de venta y demanda de los productos. Los datos indicaron que los comerciantes tenían una alta dependencia financiera de la actividad, obteniendo una renta mensual de US$ 271.49. Se observó la comercialización de 5 970kg de carne silvestre y su consumo fue confirmado por 94% de los entrevistados, que reportaron 27 etnoespecies: 19 mamíferos, seis reptiles y dos aves. El mismo porcentaje de los entrevistados (94%) han comprado carne de 18 especies silvestres: 12 mamíferos y seis reptiles. La mayoría del comercio ilegal de animales silvestres y la importante demanda de productos en la población local apuntan a la necesidad de políticas de desarrollo sostenible para las especies de caza, que garanticen la conservación del medio ambiente, una mejoría en la calidad de vida y la manutención cultural local.

In tropical forests, wild game meat represents an option or the only protein source for some human populations. This study analyzed the wildlife meat trade destined to human consumption in an open market of the Amazon rainforest, Brazil. Wildlife meat trade was monitored during 2005 through interviews to vendors and consumers in order to evaluate the socioeconomic profile of the sellers, the main species and byproducts sold, their geographical origin, commercial value, frequency of sale and product demand. Data indicated that vendors were financially highly dependant of this activity, getting a monthly income up to US$271.49. During the survey, the amount of wildlife meat on sale added a total of 5 970kg, as follows: 63.2% capybara (Hydrochoerus hydrochaeris), 34.4% cayman (Melanosuchus niger and/or Caiman crocodilus crocodilus), 1.1% paca (Cuniculus paca); 0.6% armadillo (Dasypus novemcinctus), 0.5% deer (Mazama americana), 0.2% matamata (Chelus fimbriatus), and 0.1% opossum (Didelphis marsupialis). Most of the commercialized species were not slaughtered locally. The consumption of wildlife meat was admitted by 94% of the interviewed, consisting of 27 ethno-species: 19 mammals, 6 reptiles, and 2 birds. The same percentage of the interviewed (94%) already bought wildlife meat of 18 species: 12 mammals and 6 reptiles. The great amount of wildlife meat traded and the important demand for these products by the local population, point out the necessity to adopt policies for a sustainable management of cinegetic species, guaranteeing the conservation of the environment, the improvement of living standards, and the maintenance of the local culture. Rev. Biol. Trop. 58 (3): 1079-1088. Epub 2010 September 01.

O objetivo desta pesquisa foi analisar a puberdade em fêmeas de cutias. Não foi observado o inicio da puberdade quando as fêmeas foram mantidas sem os machos. Se um macho adulto era mantido com as fêmeas adultas e não ciclantes, o inicio do ciclo estral era observado após um período de 10 a 60 dias. Quando as fêmeas jovens eram mantidas com o macho, a puberdade se estabelecia aos nove meses. Concluindo que o macho de cutia influencia o inicio da puberdade das fêmeas, e as fêmeas dominantes, aparentemente, inibem ou atrasam a puberdade de outras do grupo. Sugerem-se estudos futuros sobre o controle social na reprodução deste animal.

The objective of this research was to analyze female agouti puberty. We did not observe the onset of puberty when the females were raised without males. When an adult male was put together with other adults and no cycling females, the onset of estrous cycle was observed after 10 to 60 days. When the young females were raised with a male, the onset of puberty was reached at 9 months. We concluded that the male agouti influences the onset of puberty in females, and that the dominant female, apparently, inhibits or delays the puberty of the other agouti females of the group. We suggest further studies be made concerning the social control of the reproduction of these animal.

O objetivo do trabalho foi estudar a biologia reprodutiva da Agouti paca criada em cativeiro. Os resultados demonstraram que, a duração média do ciclo estral foi de 32,5 + 3,7 dias e o período gestacional de 148,6 + 4,8 dias. O intervalo entre partos foi de 224,5 + 52,2 dias e o primeiro cio pós-parto foi de 25,6 + 8,8 dias. A maioria (55,6 %) das fêmeas apresentou dois partos por ano, com o nascimento de um filhote por parto, sendo 44,7 % fêmeas e 55,3 % machos. Ao nascer o peso médio das fêmeas foi de 605,9 + 87,5 g e dos machos 736,7 + 108,4 g (P < 0,05). A puberdade das fêmeas ocorreu entre o 8º e 12º mês, porém neste aspecto são necessárias investigações mais detalhadas.

The objective of this paper was to study the reproductive biology of the Agouti paca raised in captivity. It was observed that the estrous cycle average was 32.5 + 3.7 days, gestation length 148.6 + 4.8 days, parturition interval 224.5 + 52.2 days, and the first post-partum 25.6 + 8.8 days. It was also observed that 55.5% of the females presented two parturitions per year with one young per parturition, of which 44.7% were females and 55.3% were males. The birth weight was 605.9 + 87.8 g for females and 736.7 + 108.4 g for males (P<0.05). Puberty in females occurred between 8 to 12 months; for this, however, more detailed investigations are necessary.