Surface temperature of ewes during estrous cycle measured by infrared thermography.

The use of infrared thermography has not been used previously to assist sheep reproduction. The aim of this study was evaluate the viability of infrared thermography to identify body surface temperature patterns during ewes' estrous cycle. The estrous cycles of 20 Santa Ines ewes were synchronized through hormone treatment (progesterone implant). The ewes were submitted to measurements of body temperature (rectal and vaginal) with a digital thermometer and surface temperature of the anus, vulva, muzzle, left ear and left eye by infrared thermography. Temperature and humidity of the environment and wet-bulb globe temperature (WBGT) were measured. After the progesterone implant's removal, the follicular dynamic was evaluated daily during five days with ultrasound. The estrous cycle was separated into six phases to facilitate interpretation of the differences in body temperatures in each period. Phase 1 was the period before estrous synchronization, phase 2 was the beginning of estrous synchronization, phase 3 was the intermediate period and end of synchronization, phase 4 was the period of estrus manifestations, phase 5 was the ovulation period, and phase 6 was the post-ovulatory period. There was a difference among phases for all body regions evaluated (P < 0.05). All temperatures were higher in the ovulation phase. The rectal and vaginal temperatures measured by digital thermometer were lower during the diestrus period and increased during and after ovulation. The surface temperature of the vulva, measured by thermography, was higher from the estrus phase (4) to the ovulation and post-ovulation phases (5 and 6). The surface temperature of the muzzle was higher from the ovulation phase (5) to the post-ovulation phase (6), showing potential to detect ovulation. The thermography was efficient to detect small temperature variations during different phases of the estrous cycle, allowing the identification of different phases of the cycle in Santa Ines ewes.

Trichomonas adhere and phagocytose sperm cells: adhesion seems to be a prominent stage during interaction.

Tritrichomonas foetus and Trichomonas vaginalis are extracellular parasites of the urogenital tract of cattle and humans, respectively. They cause infertility and abortion, but there is no documented information on the susceptibility of bovine sperm cells to this cattle parasite. The aim of this present work was to study the effects provoked by T. foetus and T. vaginalis when in interaction with bovine and human sperm cells. The bovine and human spermatozoa were obtained from uninfected bulls and men, respectively, and were exposed to living trichomonads over different periods of time. Light microscopy, video microscopy, scanning, and transmission electron microscopy first revealed a tropism, then a close proximity followed by a tight adhesion between these two different cells. A decrease in the spermatozoa motility was observed as well intense semen agglutination. The adhesion between trichomonads to the sperm cell occurred either by the flagella or sperm head. Motile parasites were observed during the next 12 h, whereas sperm cells in contact with the parasites rapidly became immotile. The parasites were able to maintain the sperm cells attached to their cell surface, followed by phagocytosis. This process began with a tight membrane-membrane adhesion and the incorporation of the sperm cell within an intracellular vacuole. Afterwards, the sperm cell was gradually digested in lysosomes. Many trichomonads were injured and/or died on making contact with the spermatozoa possibly due to necrosis. Results from this study demonstrated that both T. foetus and T. vaginalis interact with sperm cells provoking damage and death of these reproductive cells. Differences in the behavior of both trichomonads were evident, showing that T. vaginalis was much more virulent than T. foetus. The possible role of trichomonads in reproductive failure is discussed.

Tritrichomonas foetus damages bovine oocytes in vitro.

Tritrichomonas foetus is an extracellular parasite of the urogenital tract in cattle. It causes infertility and abortion, but there is no documented information on the susceptibility of bovine oocytes to the parasite, except by one article that claimed no effects of T. foetus on oocytes or embryos. The aim of the present study was to study the effects provoked by T. foetus when in interaction with bovine oocytes. Oocytes were obtained from cow ovaries and divided into two groups: (1) one group contained cumulus cells, whereas (2) a second group was denuded from these cells. Light microscopy, video microscopy and scanning electron microscopy (SEM) revealed that exposure of oocytes to T. foetus caused rapid adhesion of the trichomonads to cumulus cells and to the zona pellucida (ZP). Motile parasites were observed for 12 h. The ZP was completely damaged, and the parasites were able to infiltrate beneath the ZP and reached the oocytes directly when the oocytes were denuded of the cumulus cells. Both the oocytes and the cumulus cells exhibited morphological characteristics compatible with apoptosis after interaction with T. foetus, such as chromatin condensation, the presence of several cytoplasmic vacuoles, with intact cellular membranes and organelles. The results from this study demonstrate that when a large number of T. foetus interacts with oocytes in vitro damage and apoptosis are provoked in the cow's reproductive cells. The behavior of this parasite as one of the causes of cattle infertility is discussed.