Associated and independent comparisons between the two largest follicles preceding follicle deviation in cattle
MetadataShow full item record
Follicle diameters and concentrations of follicular fluid factors were studied in the two largest follicles (F1 and F2) using F1 diameters in increments of 0.2 mm (equivalent to 4 h intervals) and extending from 7.4 to 8.4 mm (12 heifers in each of 6 groups). Changes were compared between follicles using the F2 associated with each F1-diameter group. Diameter deviation began in the 8.2-mm group as indicated by a greater (P < 0.05) diameter difference between F1 and F2 in the 8.4-mm group than in the 8.2-mm group. In the 8.0-mm group, estradiol concentrations began to increase (P < 0.05) differentially in F1 versus F2, and free insulin-like growth factor-1 (IGF-1) began to decrease differentially in F2 (P < 0.06). Combined for F1 and the associated F2, activin-A concentrations increased (P < 0.05) between the 7.6- and 8.2-mm groups and then decreased (P < 0.05). Results supported the hypothesis that estradiol and free IGF-1 concentrations simultaneously become higher in F1 than in the associated F2 by the beginning of diameter deviation. Results did not support the hypothesis that a transient elevation in activin-A is present in F1 but not in the associated F2 at the beginning of the estradiol and IGF-1 changes; instead, a mean transient elevation in activin-A occurred at this time only when data for the two follicles were combined. Comparisons between F1 and F2 also were made by independently grouping F2 and using diameter groups at 0.2-mm increments for F2 as well as for F1. In the diameter groups common to F1 and F2 (7.4, 7.6, 7.8, and 8.0 mm) there was a group effect (P < 0.003) for estradiol involving an increase (P < 0.05) beginning at the 7.6-mm group averaged over F1 and F2. For free IGF-1 concentrations, a fluctuation (a significant increase followed by a significant decrease) occurred independently in F1 between the 7.4-to 7.8-mm groups and independently in F2 between the 7.0- to 7.4-mm groups.
How to cite this document
Showing items related by title, author, creator and subject.
Temporal interrelationships among luteolysis, FSH and LH concentrations and follicle deviation in mares Gastal, E. L.; Gastal, M. O.; Nogueira, G. P. ; Bergfelt, D. R.; Ginther, O. J. (Theriogenology, 2000) [Artigo]The effect of altered LH concentrations on the deviation in growth rates between the 2 largest follicles was studied in pony mares. The progestational phase was shortened by administration of PGF2α on Day 10 (Day 0=ovulation; ...
Follicular dynamics and plasma FSH and progesterone concentrations during follicular deviation in the first post-ovulatory wave in Nelore (Bos indicus) heifers Castilho, Caliê; Garcia, Joaquim M.; Renesto, Andrea; Nogueira, Guilherme P.; Brito, Leonardo F. C. (Animal Reproduction Science, 2007) [Artigo]The objective of the present study was to characterize ovarian follicular dynamics and hormone concentrations during follicular deviation in the first wave after ovulation in Nelore (Bos indicus) heifers. Ultrasonographic ...
Andrade, Evelyn R.; Van Den Hurk, Robert; Lisboa, Lívia A.; Hertel, Mariana F.; Melo-Sterza, Fabiana A.; Moreno, Kleber; Bracarense, Ana Paula F.R.L.; Landim-Alvarenga, Fernanda C. ; Seneda, Marcelo M.; Alfieri, Amauri A. (Zygote, 2012) [Artigo]The objective of this study was to evaluate the effects of adding ascorbic acid to the media for in vitro culture of cattle ovarian fragments and to determine their effects on growth activation and viability of early-stage ...