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Start Over Descriptor "time of ovulation" Topic ovulation
2 results on '"time of ovulation"'

1. Study upon the Moment of Ovulation in Sows to Establish the Optimum Moment for Semen Inoculation.

Author

Sandu, Mariana, Mantea, Ştefan, Ipate, Iudith, Kruzslicika, Mihaela, and Chiriţescu, Vergina

Subjects
*OVULATION, *ARTIFICIAL insemination, *SOWS, *MAMMAL reproduction, *MAMMAL spermatozoa, *ESTRUS, *SWINE, *ANIMAL sexual behavior, *REPRODUCTION
Abstract

Efficiency of artificial insemination depends equaly by semen quality and time of inoculation. The optimal time for inoculation was calculated usually from the moment of detection of heat, for double insemination, so that one of the two inoculations to approach the time of ovulation. To increase the efficiency of boars exploitation is necesary to change the method to a single insemination. To ensure normal fertility parameters with only one inoculation it is necessary to chose with great precision the moment of insemination ,in order to ensure the time for sperm capacitation and penetration of viable oocytes. Starting from the fact that major events such as forrowing and death occur, according to the circadian rhythm, in the second half of the night, this study aims to detect from this point of view the moment of ovulation, to find a more reliable calculation for the time of semen inoculation. The experiments were conducted on puberal gilts, which were not treated for induction of ovulation; the control for detecting the follicular dehiscence was done only on physiological oestrus. Females having symptoms at heat control were subject to series of laparatomias, complete with collection and examination of oocytes. [ABSTRACT FROM AUTHOR]

Published
2012

2. Momento da ovulação em ovelhas corriedale após cio natural e induzido com progestágeno e eCG

Author

Lúcia Martins Chagas, Adilson Moura, José Carlos Ferrugem Moraes, and Carlos José Hoff de Souza

Subjects
Estrous cycle, sheep, General Veterinary, media_common.quotation_subject, Artificial insemination, medicine.medical_treatment, ovinos, Semen, momento de ovulação, Biology, cio natural, induced estrus, Andrology, medicine, Animal Science and Zoology, natural estrus, Agronomy and Crop Science, Ovulation, time of ovulation, media_common, cio induzido
Abstract

Durante a estação reprodutiva (março e abril), dois experimentos foram conduzidos com 116 ovelhas da raça Comedale, objetivando verificar o momento de ovulação nesta raça após estro natural ou induzido com ou sem o "efeito macho". As ovelhas foram submetidas a laparoscopia em intervalos de quatro horas entre 20 e 40 horas depois da identificação do início do cio natural e entre 48 e 120 horas em cada uma de duas repetições após a remoção dos pessários impregnados com 50mg de medroxiprogesterona e injeção de 500UI de eCG (gonadotrofina sérica equina)ou até a ovulação ser observada. Após o cio natural, 96% de 56 ovelhas ovularam sendo a maioria (85%) entre 24 e 32 horas do início do cio. No grupo de 60 ovelhas submetido a indução de cio foi constatado que na média as ovulações ocorreram as 65,1±2,2 horas e 73,8±3,2 horas após a remoção dos pessários, respectivamente, para os grupos submetidos ou não ao efeito macho (P < 0,05). As ovulações não foram afetadas pela idade das ovelhas e repetição dos tratamentos hormonais. O momento de ovulação após o cio natural apresenta pouca variação, já após cio induzido constatou-se antecipação nas ovulações com o efeito macho sem alteração na amplitude de variação, fato este, que pode ser responsável pela variabilidade nas taxas de concepção após inseminação com sêmen congelado. The aim of the present study was to verify the time of ovulation after natural or induced estrus in the Comedale ewe. The ram effect was also evaluated in the presence of induced estrus. Both treatments were examined by laparoscopy every four hours, from 20h to 40h after beginning the natural estrus, and from 48h to 120h after withdrawing the sponges or until ovulation was observed. After natural estrus, 96% from 56 ewes had ovulated, and most of the ovulations (85%) had occurred from 24 to 32h after the onset of heat. The mean time of ovulation in 60 ewes treated with progestagen pessaries (50mg, MAP, 12 days) and eCG injection (500IU at sponge withdrawai) was 65.1 ± 2.2h and 73.8 ± 3.2h respectively for groups with and without the presence of rams. This trait was affected by the ram effect (P < 0.05); however, it was neither influenced by the age of the ewes nor the repeated hormonal treatments. The time of ovulation after natural estrus, due to its small variation, is not likely to affect the results of artificial insemination with frozen semen. On the contrary, the time of ovulation, but not the range of ovulation distribution, was significantly increased in ewes with induced estrus when in the presence of rams. These results probably play a role in the success rate of the artificial insemination with frozen semen.

Published
1995

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