The influence of the corpus luteum on ovarian follicular dynamics during estrous synchronization in goats.
Ovarian follicular dynamics and fertility are unaffected by the presence or absence of a corpus luteum during synchronization of estrus with progestins in goats. On day 5 of the estrous cycle (estrus= day 0), a gestagen-containing sponge was inserted in the vagina for 11 days. To remove corpora lutea, one group of goats (CL-, n=41) received 7.5 mg of luprostiol on days 7 and 8 of the estrous cycle. The second group of goats retained the CL (CL+, n=38). Growth and development of follicles > or =4 mm in diameter were measured daily from onset of estrus to 2 days after subsequent ovulation in seven goats from each group, using rectal ultrasonography. Estrus was detected by the use of a reproductively sterilized buck and estrous does were subsequently mated. The number of waves of follicular development (CL- =3.57+/-0.2 versus CL+ =3.14+/-0.14; P>0.05) did not differ between groups. The second wave of follicular development was present at the time of progesterone decline in the CL- group and neither its duration (CL- =4.8+/-0.4 versus CL+=5.6+/-0.7 days; P>0.05) nor the day of commencement of the third wave of follicular development (CL -=11.6+/-0.7 versus CL+=11.8+/-0.6; P>0.05) were altered by the concentration of endogenous progesterone. The pregnancy rate was similar between the two groups. (CL-=68.29% versus CL+=65.79%; P>0.05). Thus, in goats, ovarian follicular dynamics and fertility were not altered by the presence or absence of a corpus luteum during estrous synchronization.
Lassala
A
A
Departamento de Reproducción, Facultad de Medicina Veterinaria, Universidad Nacional Autónoma de México, Av. Universidad 3000, México D.F. 04510, Mexico.
Hernández-Cerón
J
J
Rodríguez-Maltos
R
R
Gutierrez
C G
CG
D000818:Animals; D003338:Corpus Luteum / Q000000981:diagnostic imaging / Q000502:physiology*; D004973:Estrus Synchronization / Q000502:physiology*; D005260:Female; D006041:Goats / Q000502:physiology*; D008297:Male; D006080:Ovarian Follicle / Q000000981:diagnostic imaging / Q000502:physiology*; D010060:Ovulation / Q000502:physiology; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D018709:Statistics, Nonparametric; D014463:Ultrasonography
D011374:Progesterone