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We study rheotaxis of bull sperm inside microchannels to characterize the effects of flow and wall shape on sperm swimming behavior. We found that a large percentage of sperm cells, 80 to 84%, exhibited positive rheotaxis (sperm cells swimming against the flow) within flow velocities of 33 to 134 μm s(-1). Sperm cells were also found to reverse their swimming direction when the liquid flow direction was reversed. Time taken by sperm cells to reverse their swimming direction was inversely proportional to the flow velocity. Sperm behavior was significantly affected by the sperm position with respect to the channel wall. Sperm cells close to the channel wall moved upstream faster than sperm cells moving along the channel centerline. Shear stress, which is an indicator of velocity distribution, was found to play an important role in regulating rheotactic behavior of sperm cells. Side pockets were added to some microchannels to mimic storage sites in mucosal folds and pockets in the fallopian tube of the female reproductive system and sperm interaction with these pockets was monitored. We found that sperm cells tend to follow channel walls and enter these pockets without any chemical binding, which further confirms the wall tracking behavior of mammalian sperm cells. Our results confirm that sperm rheotaxis is a strong mechanism for guiding sperm cells towards the oocyte along the female genital tract.

The objective of this study was to investigate the effects of pre and post-lambing intramuscular (i.m.) injections of vitamin E (VE) and selenium (Se) on the performance, reproductive indices and metabolic status of Ossimi ewes. A total of 20 pregnant ewes were divided randomly into two equal groups of ten animals. The control group (CG) was administered 3 ml of normal saline. The treated group (TG) was administered a combination of 5 mg of sodium selenite and 450 mg of VE twice weekly for 2 weeks pre and post lambing. The performance, reproductive indices, colostrum and milk mineral profiles, blood metabolites and antioxidant enzyme biomarkers were investigated in this experiment. VE and Se supplementation had a significant effect on ewe, lamb performance, colostrum and milk mineral profiles. The treated ewes lost less weight (0.7 kg) compared with the ewes in the control group (3.68 kg) on 30 th day postpartum (P<0.001). Lambs born to treated ewes were heavier than those born to control ewes (4.47 kg vs 3.99 kg, respectively), gained more daily weight quickly (268.66 vs. 226.00 g, respectively, P<0.001) and weighed more on 30 th day post-lambing (12.53 vs. 10.77 kg, respectively, P<0.001). Treated ewes had higher concentrations of blood glucose, total protein, total cholesterol, antioxidant enzyme biomarkers, and lower concentrations of serum non-esterified fatty acids (NEFA). VE and Se supplementation had a significant effect (P<0.05) on postpartum reproductive performance of ewes in terms of fast uterine involution, earlier resumption of ovarian function and ovulation with large size ovulatory follicles, and greater numbers of small, medium, and large-sized follicles. In conclusion, VE and Se supplementation during late gestation and early lactation could be considered an effective strategy for minimizing the weight loss of ewes, enhancing lamb performance, the antioxidant and metabolic status, which improves the reproductive performance of Ossimi ewes.

Fertility in birds is dependent on their ability to store adequate populations of viable sperm for extended durations in sperm storage tubules (SSTs). The exact mechanisms by which sperm enter, reside, and egress from the SSTs are still controversial. Sharkasi chicken sperm showed a high tendency to agglutinate, forming motile thread-like bundles comprising many cells. Since it is difficult to observe sperm motility and behavior inside the opaque oviduct, we employed a microfluidic device with a microchannel cross-section resembling close to that of sperm glands allowing for the study of sperm agglutination and motility behavior. This study discusses how sperm bundles are formed, how they move, and what role they may have in extending sperm residency inside the SSTs. We investigated sperm velocity and rheotaxis behavior when a fluid flow was generated inside a microfluidic channel by hydrostatic pressure (flow velocity = 33 µm/s). Spermatozoa tended to swim against the flow (positive rheotaxis) and sperm bundles had significantly lower velocity compared to lonesome sperm. Sperm bundles were observed to swim in a spiral-like motion and to grow in length and thickness as more lonesome sperm are recruited. Sperm bundles were observed approaching and adhering to the sidewalls of the microfluidic channels to avoid being swept with fluid flow velocity > 33 µm/s. Scanning and transmission electron microscopy revealed that sperm bundles were supported by a copious dense substance. The findings show the distinct motility of Sharkasi chicken sperm, as well as sperm's capacity to agglutinate and form motile bundles, which provides a better understanding of long-term sperm storage in the SSTs.

Pyometra is not a common disease in cats however in Egyptian veterinary clinics where owners do not usually go for elective neutering become a more common affection. It is an acute or chronic purulent endometritis, a sequel to progesterone stimulation. The traditional therapy for pyometra is ovariohysterectomy however medical treatment may be requested by owners or cat condition may not permit surgical treatment. The aim of the present study is to characterize the pyometra in cats and compare between ovariohysterectomy and medical treatment using PGF2α alone or PGF2α in combination with dopamine agonist. 45 cats were diagnosed with pyometra. Cats divided into 3 groups. Group 1 (n= 23): animals received PGF2α, Group 2 (n= 15): cats received PGF2α plus oral administration of Bromocriptine. Group 3 (n=7): went for ovariohysterectomy. Survival analysis of cats was performed in this study for 2 years after diagnosis. In G1 we censored 14 animals, eight of them returned with recurrent pyometra. The first recurrent case was recorded 3 months post-treatment. In G2 we censored 12 cats, four of them were returned with recurrent pyometra, the first recurrent case was met 8 months post-treatment. After 24 months, both G1 and G2 have no difference in the survival rate which reach for both treatment about 60% success in both groups. However, G3 survival rate was 100% success. Using dopamine agonist in medical treatment my delay the recurrences of pyometra for a short term however ovariohysterectomy whenever possible may be the best choice for treatment of pyometra.