Author(s): ARASHIRO, E. K. N.; VIANA, J. H. M.; FONSECA, J. F. da; CAMARGO, L. S. de A.; FERNANDES, C. A. de C.; BRANDÃO, F. Z.

Summary: The aim of this study was to establish the morphologic and endocrine characteristics of luteal dynamics in goats. It was used Toggenburg female goats that showed natural estrus in a 48-hour interval. After estrus, ultrasonographic evaluations of the ovaries were daily performed during 21 days using a portable device (5MHz probe). Blood sample was collected for plasma progresterone (P4) determination. Corpora lutea were detected for the first time on day 5 and progressively increased in size until D9 (1.26 ± 0.08 cm2), with no variation on subsequent days. In females with one ovulation, the first visualization of the corpora lutea was earlier than in those with multiple ovulation (4.54 ± 0.18 vs 5.74 ± 0.25 days). At the moment of the first visualization, luteal area was smaller in animals with single ovulation. Plasma P4 concentration progressively increased until day 9 and it did not show significant increase until luteolysis, characterized by a sharp decrease in P4 concentration, reaching values below 1 ng/mL in 24 hours. The luteal area slowly and gradually decreased in size. It was observed a significant positive correlation between P4 concentration and area during luteogenesis and luteolysis (r = 0.63 and r = 0.50, respectively). When corpus luteum reached its maximum size (D9), female with more than one corpora lutea, with a greater luteal tissue area, did not show P4 concentration higher than those with one ovulation (5.92 ± 0.59 vs 7.04 ± 0.79 ng/mL). These results show that luteal dynamics in Toggenbur goats follow a similar pattern to those observed in other goat breeds and luteal tissue growth was positively correlated with corpora lutea functionality.

Publication year: 2010

Types of publication: Journal article

Unit: Embrapa Dairy Cattle

Keywords: corpus luteum, goats, progesterone, ultrasonography