Histological and Ultrasonographic Monitoring of Folliculogenesis in Puerperal Ewes after Spring Lambing

Abstract

The time of the first ovulation depends on the sheep breed, feeding conditions, year season, length of lamb nursing and following galactopoiesis. The objective of the present study was to analyse the follicle status after parturition in non-lactating Improved Valachian ewes. Laparotomy with following ovariectomy was performed after lamb weaning (spring) on days 17, 24 and 32 after parturition. The ovaries were USG analysed with 5.0 MHz linear and 7.5 MHz convex transducer. Follicular data were analysed quantitatively and qualitatively. The ovaries were collected at the end of laparotomy and fixed in 10% formalin. The sections of the ovarian tissue were stained with haematoxylin and eosin and Azan staining. Ovarian slides were microscopically studied and analysed by LUCIA-G ver. 4.71. The differences in the ovary size were not significant. The number of follicles < 3 mm monitored by USG on day 32 was higher than that on day 17 after parturition. The image analysis of the ovary sections showed significantly higher numbers in the total follicles (P < 0.05) and the follicles > 3 mm (P < 0.001). The rate of atresia was 82% and 89% on day 17 and on day 32 post partum, respectively. We observed single ovulation on day 17 and double ovulations on days 24 and 32 post partum. More than half of the total number of antral follicles visible on the ovary surface was prepared for recruitment and this number was higher on day 32 post partum. Follicle selection connected with a relatively low rate of atresia and responsible preovulatory follicle sizes opened the way for selecting more follicles for the dominance process and thus also for the occurrence of double ovulations.

The effect of short-term lupin (Lupinus angustifolius) feed supplementation on serum steroid hormones, insulin-like growth factor I, and ovarian follicular development and atresia in Merino ewes

“…The ovary halves were processed using standard histological methods as described previously (24). Sections of ovarian tissues were stained with Mayer haematoxylin and eosin (25).…”

Concentrations of selected toxic elements in ewe living near an environmentally loaded area of eastern part of Slovakia

“…Bennett and Balvanera [23] support the claims by the authors of thios article about the occurrence of environmental burdens in the Spiš region as a consequence of particular former mining activities. The above-mentioned authors have elaborated on the monitoring report on the Spiš region area in which they documented the elevated values of heavy metals Zn and Cd in the environmental components in water and soil.…”

“…The analysed selected heavy metals were evaluated due to the increased occurrence of these metals in the concerned area, which have monitored in the past by the authors of the current article. The increased incidence of these heavy metals has been confirmed by the studies of several authors [1,23] who also monitored the target area. The concentrations of lead (Pb) and cadmium (Cd) in the experimental animals were determined using an inductively coupled plasma optical emission spectroscopy (ICP-OES) (PerkinElmer) OPTIMA 2100 DV.…”

Follicular Turnover and Hormonal Association in Postpartum Goats During Early and Late Lactation

“…Studies in ewes [6] indicated that residual local inhibition of follicular development by a CL of pregnancy extends to the postpartum period. Moreover, the number of small antral follicles (which constitute more than half of the total follicular population) was lowest on day 17 and highest on day 32, while the number of large follicles was highest on day 24 and slightly lower on day 32 postpartum [29]; it also seemed to be influenced by diet and can be increased by administration of GnRH [25]. In postpartum rats, suckling inhibits GnRH/LH-pulses, reduces follicular development and delays the resumption of ovulation [30].…”