Emprego da microscopia eletrônica na avaliação pós-vacinal de epitélio traqueal de patos (Anas platyrhynchos) imunizados contra a doença de Newcastle

Avaliou-se o emprego da microscopia eletrônica de varredura no estudo da reação respiratória pós-vacinal em epitélio traqueal de patos (Anas platyrhynchos) imunizados contra a doença de Newcastle. Foram utilizadas 48 aves, distribuídas em quatro grupos: T1 - grupo de aves-controle (não vacinadas), T2 - grupo de aves vacinadas com a estirpe Ulster 2C, T3 - grupo de aves vacinadas com a estirpe B1 e T4 - grupo de aves vacinadas com a estirpe LaSota. Independente do grupo experimental, as aves não apresentaram sinais clínicos detectáveis de reação respiratória pós-vacinal. Ao microscópio eletrônico de varredura, observou-se que os animais vacinados com as estirpes B1 e LaSota desenvolveram descamação epitelial da traqueia, enquanto os vacinados com a estirpe Ulster 2C não, mostrando um epitélio traqueal íntegro, semelhante ao do grupo-controle. Os patos vacinados com a estirpe B1 mostraram evidências de regeneração epitelial da traqueia decorridos 21 dias pós-vacinação, o que não ocorreu com os vacinados com a amostra LaSota.Scanning electron microscopy was used in the study of the post-vaccinal respiratory reaction of the tracheal epithelium of ducks (Anas platyrhynchos) immunized against Newcastle disease. Forty-eight ducks were distributed into four groups: T1 - control birds (non-vaccinated); T2 - birds vaccinated with Ulster 2C strain; t3 - birds vaccinated with B1 strain; and t4 - birds vaccinated with LaSota strain. Regardless the experimental group, birds did not show detectable clinical signs of post-vaccinal respiratory reaction. Scanning electron microscopy showed that birds vaccinated with B1 and LaSota strains developed epithelial sloughing of the trachea, whereas those vaccinated with Ulster 2C strain did not develop this change, showing intact tracheal epithelium, similar to the control group. However, the birds vaccinated with B1 strain showed evidences of regeneration of tracheal epithelium 21 days post-vaccination, which did not happen with the ducks vaccinated with LaSota strain

Efeito da adição de agentes tróficos na dieta de leitões desmamados sobre a estrutura e ultraestrutura do intestino delgado e sobre o desempenho

Foram estudados os efeitos da glutamina, dos ácidos graxos poli-insaturados e da parede celular de levedura (PCL) sobre a estrutura e ultraestrutura do intestino delgado e o desempenho de leitões. Foram utilizados 45 leitões, desmamados aos 21 dias de idade, para testar os seguintes tratamentos: T1 - dieta basal; T2 - dieta basal + 1% de glutamina; T3 - dieta basal + 0,2% de PCL; T4 - dieta basal + 5% de óleo de peixe. Nos dias sete e 14 pós-desmame, foram abatidos cinco leitões de cada tratamento. Os aditivos testados não alteraram a altura e a densidade dos vilos nem a profundidade das criptas do intestino delgado. Foi observado efeito de idade, mostrando redução na altura e na densidade dos vilos e na profundidade das criptas após o desmame. No duodeno e jejuno, foram observados maiores valores de relação vilo:cripta, que aumentaram com a idade pós-desmame. Ocorreram redução da altura dos microvilos do duodeno aos sete dias e aumento da largura dos microvilos do jejuno aos 14 dias pós-desmame. A área de superfície apical dos enterócitos não foi alterada pelos fatores estudados. Os aditivos estudados não foram eficientes em prevenir a atrofia da mucosa intestinal do jejuno, ao não interferir na sua ultraestrutura. Os aditivos incluídos na dieta não influenciaram o desempenho dos leitões no pós-desmame.The effects of glutamine, poliunsatured fatty acids and cellular wall of yeast (CWY) under the structure and ultra structure of the small gut and the performance of the piglets were studied. Forty five piglets weaned at 21 days were used to test the following treatments: T1 - basal diet; T2 - basal diet + 1% of glutamine; T3 - basal diet + 0,2% of CWY; T4 - basal diet + 5% of fish oil. At seven and 14 post weaning days, five piglets of each treatment were slaughtered. The height, density of villus and depth of small gut crypts were not altered by the inclusion of additives. The effect of age was observed, showing a reduction in the height and density of villus and depth of crypts after weaning. In duodenum and jejunum higher values were observed in the relation villus:crypt, which increased with the post wean age. There was a decrease in the height of microvillus of the duodenum at 7 days and an increase of the width of the microvillus of jejunum at 14 days after wean. The area of the apical surface of the enterocytes was not altered by the studied factors. The studied additives were not efficient to prevent the atrophy of the intestinal mucosa of the jejunum, since they did not interfere on its ultra structure. Piglet performance was not affected by the additives included in the diet

Induced reproduction and early development histology of Oscar Astronotus ocellatus (Agassiz, 1831)

Oscar (Astronotus ocellatus) is an important fish from the Amazon Basin that has great potential for fish farming, human consumption, sport fishing and fish keeping. This study aimed to evaluate the effect of two hormonal treatments on the induction of artificial reproduction in broodstock and to describe the histological development of embryos and larvae. Broodstocks were selected and induced using two different hormones: (i) extract of carp pituitary (ECP); and (ii) synthetic human chorionic gonadotropin (hCG). Spawnings were transferred to hatcheries, collected at pre-established times, processed and analysed by histology. Astronotus ocellatus did not respond well to induced reproduction. From 16 couples of breeding fish, only five out of the eight females released oocytes after the hormonal action time, three with hCG and two with ECP; just one male responded positively to hCG. Oscar eggs were oval, and semi-adhesive, the yolk contained granules, and egg diameter was approximately 1.65 ± 0.057 to 1.98 ± 0.038 mm. Development from the initial collection (IC) point until the total absorption of the yolk lasted 315 h, at an average temperature of 27.45 ± 2.13°C. Several events marked embryonic and larval development, including the formation of the optic cup, forebrain, otic vesicle and cephalic divisions. The newly hatched larvae had non-pigmented eyes, and a closed mouth and anus, as well as the presence of adhesive glands on the head. Larval development was characterized by formation of the heart, liver, gaseous bladder, gills, pronephros, brain, fins and also the digestive tract. These results provide important information for the rearing and reproduction of A. ocellatus. Copyright © Cambridge University Press 2013

Efeito do resfriamento sobre a textura post-mortem da carne do peixe matrinxã Brycon cephalus Chilling effect on the post-mortem texture of the matrinxã fish muscle Brycon cephalus

Os mecanismos que causam o amolecimento e a perda na textura post-mortem da carne de matrinxã foram determinados por meio das mudanças na microestrutura do músculo, imediatamente após a morte e depois de 12 horas de estocagem a -3&deg;C. As observações na microestrutura, realizadas com microscópio eletrônico de transmissão, foram semelhantes aos resultados obtidos na força de ruptura do músculo medidos com o texturômetro. Os valores da força da ruptura foram menores para a carne após o resfriamento. Observou-se que as fibras do colágeno do tecido conectivo pericelular se desintegraram e que as do colágeno do tecido conectivo do miocommata conservaram sua arquitetura e integridade. Houve pouca degradação da linha Z. Isso sugere que o amolecimento post-mortem da carne de mantrinxã, durante a estocagem a -3&deg;C, é causado pela degradação do tecido conectivo pericelular.<br>In order to determine the mechanisms that cause the post mortem muscle softness of the matrinxã Brycon cephalus, changes in the micro structure of the muscle were observed immediately after death and after 12 hours of storage at -3º C, measuring the firmness of the flesh with test instruments. Observations by the transmission electron microscope were similar to the results obtained in the breaking strength of the muscle measured with a texturometer. The values of the breaking strength of the fish muscle were smaller after chilling. At the same time, it was observed that the collagen fibers of the pericellular connective tissue had disintegrated, while the collagen fibers of the miocommata connective tissue maintained their organization and integrity. No evident breakdown of Z-discs was observed. It is suggested that the post-mortem tenderization of the matrinxã muscle during chilled storage was due to the disintegration of the collagen fibers in the pericellular connective tissue and, in a smaller extent, to the weakening of Z-disk