Qualidade do sêmen em tilápia do Nilo (Oreochromis niloticus), alimentadas com dietas contendo diferentes níveis de vitamina C.

A vitamina C atua na proteção de danos celulares provocados pelos radicais livres, sendo a suplementação considerada essencial para a maioria das espécies de peixes, uma vez que não a sintetizam em função da ausência da enzima L-gulonolactona oxidase. Assim, avaliou-se o efeito da suplementação de 0, 75, 150 e 225 mg de vitamina C kg-1 de ração na qualidade do sêmen em tilápias do Nilo (Oreochromis niloticus). Os parâmetros quali-quantitativos do sêmen não foram influenciados pela suplementação de vitamina C, exceto a motilidade progressiva que aumentou linearmente com adição de vitamina C. Conclui-se que os reprodutores de tilápias do Nilo devem ser suplementados com 225 mg de vitamina C kg-1 de ração

Quality of fresh and cryopreserved semen and their influence on the rates of fertilization, hatching and quality of the larvae of Piaractus mesopotamicus

Abstract In this work, the seminal parameters of P. mesopotamicus were evaluated fresh and after cryopreservation, focusing on the sperm variables that affect the rates of fertilization, hatching and post-hatching parameters such as larval survival and morphology. The semen and oocytes from the animals were collected after extrusion, and seminal quality and oocyte fertilization were analyzed. Subsequently, a portion of each semen sample was cryopreserved and, after two days, the oocytes from three new females were fertilized with cryopreserved semen from the males. The analyzes showed that progressive motility, spermatic vigor, motility duration, number of normal sperm and secondary abnormalities were higher in fresh semen than in semen after thawing (P <0.0001). Similarly, fertilization and hatching rates and the percentage of normal and abnormal larvae in fertilized oocytes were higher when fresh semen was used (P <0.0001). The cryopreservation process affected the qualitative parameters of the semen of Piaractus mesopotamicus. The primary abnormality of spermatozoa was the main variable that influenced both fertilization and hatching rates, both in fresh and thawed semen. The second most important variable that influenced, particularly, thawed semen, was the spermatic vigor

Reduce glutathione and atp in the seminal cryopreservation of tambaqui.

Made available in DSpace on 2019-01-28T23:44:17Z (GMT). No. of bitstreams: 1 Cryoletters.pdf: 158601 bytes, checksum: 686e22c0b4d64043f334a7704cd1e67f (MD5) Previous issue date: 2019-01-28bitstream/item/191419/1/Cryoletters.pd

Reduce glutathione and atp in the seminal cryopreservation of tambaqui.

Made available in DSpace on 2019-01-28T23:44:17Z (GMT). No. of bitstreams: 1 Cryoletters.pdf: 158601 bytes, checksum: 686e22c0b4d64043f334a7704cd1e67f (MD5) Previous issue date: 2019-01-28bitstream/item/191419/1/Cryoletters.pd