The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti).

The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.

Anthelmintic usage on the performance of the Agouti (Dasyprocta leporina) reared intensively in Trinidad and Tobago, West Indies / Uso de anti-helmíntico no desempenho da cutia (Dasyprocta leporina) criada intensivamente em Trinidad e Tobago, Índias Ocidentais

Anthelmintic drugs have been used strategically in livestock reared in the tropics. These drugs have been used in the treatment of endoparasitism which have resulted in an increase in the animals’ performance. The agouti (Dasyprocta leporina) is a neo-tropical rodent with the potential for domestication and has been farmed intensively in Trinidad. However, the objective of this research was to investigate the effect of anthelmintic use of the growth performance of the agouti. In searching the literature, it was found that this type of study on the agouti has not been done. In this experiment fourteen weaned agoutis weighing 1kg were divided into two groups randomly. The first group (T1) was not given any anthelmintic treatment but the second group (T2) was treated with Endovet Ces® subcutaneously every three months. There were no significant differences (p > 0.05) between the two groups in the carcass weight, weight gain, dressing percentage (hot and cold), heart, lungs, skin, head and feet. However, a significant difference (p < 0.05) was seen between groups in the weight of liver and pluck. To the authors knowledge this is the first time that carcass parameters has been presented in literature. The live weight of the animals at the end of the experiment ranged from 2.4 kg to 2.6 kg and animals had a dressing percentage of 57% to 55%. The results are suggestive that the use of anthelmintic drugs in agoutis reared intensively had no significant effect on weight gain and dressing percentage.

Drogas anti-helmínticas têm sido usadas estrategicamente em rebanhos criados nos trópicos. Essas drogas têm sido utilizadas no tratamento do endoparasitismo, o que resultou em um aumento no desempenho dos animais. A cutia (Dasyprocta leporina) é um roedor neotropical com potencial para domesticação e tem sido criada intensivamente em Trinidad. Porém, o objetivo desta pesquisa foi investigar o efeito do uso de anti-helmínticos no desempenho de crescimento da cutia. Através de uma busca na literatura, constatou-se que esse tipo de estudo na cutia não foi realizado. Neste experimento, quatorze cutias desmamadas pesando 1kg foram divididas em dois gruposale atoriamente. O primeiro grupo (T1) não recebeu nenhum tratamento anti-helmíntico, mas o segundo grupo (T2) foi tratado com Endovet Ces® por via subcutânea a cada três meses. Não houve diferenças significativas (p> 0,05) entre os dois grupos no peso da carcaça, ganho de peso, porcentagem de cobertura (quente e frio), coração, pulmão, pele, cabeça e pés. No entanto, uma diferença significativa (p <0,05) foi observada entre os grupos no peso do fígado e depenagem. Para os autores, esta é a primeira vez que parâmetros de carcaça são apresentados na literatura. O peso vivo dos animais ao final do experimento variou de 2,4 kg a 2,6 kg e os animais tinham uma porcentagem de curativo de 57% a 55%. Os resultados sugerem que o uso de anti-helmínticos em cutias criadas intensivamente não teve efeito significativo no ganho de peso e na porcentagem de curativo.

External morphology and biometry of newborn agouti (Dasyprocta prymnolopha, Wagler 1831) / Morfologia externa e biometria de neonates de cutias (Dasyprocta prymnolopha, Wagler 1831)

Morphological features are essential to assess neonates' viability. In order to characterize the morphology and biometry of newborn agouti, 36 animals born at 103 days of gestation under human care in Teresina-PI, Brazil were evaluated. After birth, the newborns were weighed on digital precision scales, measured with a flexible tape measure and their external morphology was assessed. The animals observed had coat color trait of adults, open eyes, hairs in the nasal region and four incisor teeth. The forelimbs had developed four digits and the hind limbs three digits, with white edged claws and a short hairless tail. The following were observed: weight of 144.58 ± 33.39g and lengths: crown-rump 14.73 ± 1.82cm, total 19.88 ± 1.52cm, head to tail 16.95 ± 1.55cm, head 7.33 ± 0.59cm, thoracic girth 11.78 ± 1.36cm, abdominal girth 10.73 ± 1.21cm, tail length 1.18 ± 0.25cm, eye diameter 1.27 ± 0.27cm and ear length 0.21 ± 0.35cm. The agoutis presented morphological maturity at birth with external morphology very similar to that of the adult animals. Most of the births in this species are the double type and newborns that weigh more than 90g have better chances of survival in captivity.

As características morfológicas são essenciais para avaliar a viabilidade dos neonatos. Para caracterizar a morfologia e biometria de cutias recém-nascidas, foram avaliados 36 animais nascidos aos 103 dias de gestação sob cuidados em Teresina-PI, Brasil. Após o nascimento, os recém-nascidos foram pesados em balança digital de precisão, medidos com fita métrica flexível e avaliada sua morfologia externa. Os animais observados apresentavam traço de pelagem de adultos, olhos abertos, pelos na região nasal e quatro dentes incisivos. Os membros anteriores desenvolveram quatro dedos e os membros posteriores três, com garras brancas afiadas e uma cauda curta e sem pêlos. Foram observados: peso de 144,58 ± 33,39g e comprimentos: garupa 14,73 ± 1,82cm, total 19,88 ± 1,52cm, cabeça a cauda 16,95 ± 1,55cm, cabeça 7,33 ± 0,59cm, perímetro torácico 11,78 ± 1,36cm, abdominal perímetro 10,73 ± 1,21 cm, comprimento da cauda 1,18 ± 0,25 cm, diâmetro do olho 1,27 ± 0,27 cm e comprimento da orelha 0,21 ± 0,35 cm. As cutias apresentaram maturidade morfológica ao nascimento com morfologia externa muito semelhante à dos animais adultos. A maioria dos nascimentos nesta espécie são do tipo duplo e recém-nascidos que pesam mais de 90g têm melhores chances de sobrevivência sob cuidados humanos.

Post-implantation development of red-rumped agouti (Dasyprocta leporina Linnaeus, 1758).

Fourteen pregnant agouti (Dasyprocta leporina Linnaeus, 1758) females at gestational ages of 30-100days and two at gestational ages of 55-100days, were studied, including 24 embryos/fetuses and two neonates (single offspring from two females). Females were euthanized and embryos/fetuses were examined, measured, and photographed. Embryos at 30days post-copulation were "C-shaped," with paddle-shaped limb buds and 10.75±0.11mm crown-rump length (CRL). In embryos at 35days post-copulation, paddle-shaped forelimbs, fin-shaped pelvic limbs, and a liver bud were evident, with 15.6±0.16mm CRL; at 45days, mouth and nostrils were evident, lower incisors were emerging, and tactile hairs could be seen near the nostrils, with 40.8±0.4mm CRL; at 55days, cranial sutures had fused, digits were totally separated and claws formation was beginning, with 58.8±0.1mm CRL; at 65days, the genital bud had differentiated, with 83±0.08mm CRL; at 85days, the body was covered with short hair, with 127.7±0.6mm CRL; and at 100days, the mature fetus had fully formed teeth and claws and an open external acoustic meatus, with 164.3±10.4mm CRL. Neonates had bristly hair and open eyes, with 179.1±0.5mm CRL. In conclusion, characteristics of the embryo/fetus during pregnancy can be used to estimate gestational age, and can be used as parameters during ultrasound examinations to help identify developmental pathologies and to test effects of nutrition, drugs, and pollution on pregnancy.

The quantification of testicular cells during the postnatal development in two Caviomorph rodents: the guinea pig (Cavia porcellus) and the cutia (Dasyprocta agouti)

ABSTRACT The germinative, Sertoli and Leydig cells of two caviomorph rodents (Cavia porcellus and Dasyprocta agouti) were counted as well as the estimation of the total volume of the testis and the total volume of seminiferous tubules and interstitium in prepubertal, pubertal and adult animals. The number of spermatogonia, spermatocytes and spermatids cells increased during the pubertal phase in both rodents, notably the spermatid cells. The spermatocyte and spermatid slightly decreased in the adult of both rodents, but the increment in spermatogonia cells number was seen, mainly in cutias. The number of Sertoli cells increased in pubertal rodents, but in the adult the number reduced. Substantial number of Leydig cells was counted in pubertal and adult guinea pigs. In cutias, the number of Leydig cells increased in pubertal phase and decline in adults. The design-based stereological method has proven to be unbiased and reliable to be applied in reproduction studies.