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Advisor(s)
Abstract(s)
O objectivo deste trabalho foi a
determinação do momento do estro e da
ovulação em cabras após a aplicação de
dois protocolos de sincronização éstrica.
Em Maio, foram aplicadas em doze cabras
nulíparas da raça Serrana, esponjas
vaginais impregnadas com fluorgestona.
No 12º dia, procedeu-se à remoção da
esponja (RE) e foi injectado (I.M.) 50 μg
de cloprostenol. Simultaneamente, foi
administrado (I.M.) 500 UI de eCG ao
grupo 1 (G1; n=6) e 500 UI de hCG ao
grupo 2 (G2; n=6). Foi usado um bode
com arnês marcador para a detecção do
estro. Para determinação do pico préovulatório
de LH, foi colhido sangue cada
4 horas durante as primeiras 24 horas
após o início do estro. O momento da
ovulação foi determinado por ecografia,
cada 4 horas, entre as 20 e 44 horas após
o início do estro. Os corpos lúteos foram
contados 7 a 10 dias após a ovulação. Em
duas cabras do G2 não foi detectado o
pico de LH nem o momento da ovulação.
O intervalo RE – estro foi de 34,7 ± 0,9
horas (n=6) e 39,6 ± 4,8 horas (n=4;
P>0,05) para o G1 e G2, respectivamente.
Foi observada uma tendência para um
menor intervalo RE – pico de LH no G1
(38,7 ± 0,9 horas) que no G2 (44,6 ± 3,2
horas; P=0,07). A ovulação ocorreu mais
cedo, após a RE, no G1 (58,7 ± 0,9 horas)
do que no G2 (65,6 ± 3,4 horas; P≤0,05).
O número médio de corpos lúteos foi de
3,5 ± 0,2 no G1 e de 2,5 ± 0,3 no G2
(P≤0,05). Os resultados sugerem que a
eCG é mais eficiente na sincronização do
estro e estimula a ovulação mais cedo que
a hCG após a remoção das esponjas em
cabras nulíparas.
This study aimed to establish the time of oestrus and ovulation after application of two hormonal protocols in goats. In May, vaginal sponges impregnated with fluorgestone were inserted in twelve nulliparous Serrana goats. After 12 days, at sponge withdraw (SW), 50 μg of cloprostenol were injected (I.M.). Half the goats (G1; n=6) were also injected with 500 IU of eCG and the other half (G2; n=6) with 500 IU of hCG. One buck equipped with a harness was used for oestrus detection. Blood samples were collected every 4 hours, until 24 hours after the onset of oestrus, for preovulatory LH peak determination. Time of ovulation was determined by ultrasonography observations, performed every 4 hours, between 20 and 44 hours after the onset of oestrus. Corpora lutea were counted between 7th and 10th day after ovulation. Preovulatory LH peak and ovulation were not detected in two G2 goats. The onset of oestrus was observed 34.7 ± 0.9 hours and 39.6 ± 4.8 hours (P>0.05) after sponge withdraw in G1 and G2 goats, respectively. The interval between SW and preovulatory LH peak tended to be shorter in G1 (38.7 ± 0.9 hours) than in G2 goats (44.6 ± 3.2 hours; P=0.07). G1 goats (58.7 ± 0.9 hours) ovulated earlier than G2 goats (65.6 ± 3.4 hours; P≤0.05). Mean number of corpora lutea observed per goat was 3.5 ± 0.2 and 2.5 ± 0.3 in G1 and G2 goats, respectively (P≤0.05). These results suggest that eCG is more efficient for oestrus synchronisation and stimulates ovulation sooner than hCG in nulliparous goats.
This study aimed to establish the time of oestrus and ovulation after application of two hormonal protocols in goats. In May, vaginal sponges impregnated with fluorgestone were inserted in twelve nulliparous Serrana goats. After 12 days, at sponge withdraw (SW), 50 μg of cloprostenol were injected (I.M.). Half the goats (G1; n=6) were also injected with 500 IU of eCG and the other half (G2; n=6) with 500 IU of hCG. One buck equipped with a harness was used for oestrus detection. Blood samples were collected every 4 hours, until 24 hours after the onset of oestrus, for preovulatory LH peak determination. Time of ovulation was determined by ultrasonography observations, performed every 4 hours, between 20 and 44 hours after the onset of oestrus. Corpora lutea were counted between 7th and 10th day after ovulation. Preovulatory LH peak and ovulation were not detected in two G2 goats. The onset of oestrus was observed 34.7 ± 0.9 hours and 39.6 ± 4.8 hours (P>0.05) after sponge withdraw in G1 and G2 goats, respectively. The interval between SW and preovulatory LH peak tended to be shorter in G1 (38.7 ± 0.9 hours) than in G2 goats (44.6 ± 3.2 hours; P=0.07). G1 goats (58.7 ± 0.9 hours) ovulated earlier than G2 goats (65.6 ± 3.4 hours; P≤0.05). Mean number of corpora lutea observed per goat was 3.5 ± 0.2 and 2.5 ± 0.3 in G1 and G2 goats, respectively (P≤0.05). These results suggest that eCG is more efficient for oestrus synchronisation and stimulates ovulation sooner than hCG in nulliparous goats.
Description
Keywords
Estro Ovulação LH
Citation
REDVET. ISSN 1695-7504. 8:6 (2007) p. 1-6