Effects of Exercise on Donkey Semen Parameters and Some Physiological Indices.

To study the effects of exercise on donkey semen parameters, Dezhou donkey (Equus asinus) jackasses (n = 18) were assigned to three groups: control (CN, n = 6), 1-hour exercise (1 h EX, n = 6) and 2-hour exercise (2 h EX, n = 6) groups. They were exercised with a walking machine for 3 days/week for 8 weeks. Semen parameters and reproductive hormones were evaluated weekly. The heart rate, rectal temperature, blood haematology indexes, and the body condition score (BCS) were also measured. Results showed that the ejaculation volume increased while the sperm concentration decreased after exercise. However, other sperm parameters were unaffected. Reproductive hormones at resting period were rarely affected by exercise. The red blood cell number increased (P = .023), while the mean erythrocyte hemoglobin concentration decreased (P = .045) after the 8-week exercise in the 2 h EX group compared with the CN. After the 8-week exercise, the resting heart rate of the two exercise groups decreased significantly compared with the CN. The BCS in the CN group increased after the experiment (P = .024). In conclusion, we found that exercise had positive effects on some physiological indices but did not affect semen parameters expect for volume and concentration of the jackass.

Practical protocols for timed artificial insemination of jennies using cooled or frozen donkey semen.

BACKGROUND: With the expansion of the donkey industry, timed artificial insemination (TAI) is becoming increasingly important in the reproductive management of jennies, however, TAI has not been widely investigated in donkeys. OBJECTIVES: To develop efficient TAI protocols for cooled or frozen semen in jennies, based around ovulation induction with a GnRH analogue. STUDY DESIGN: Experimental exploratory study. METHODS AND RESULTS: In experiment 1, the effects of different GnRH analogue (deslorelin) doses, follicle diameter (FD) at induction, repeated use of a GnRH analogue, and the influence of season on induction efficiency, as well as distribution of ovulations over time after induction were investigated. Induction efficiency was sufficient with 2.2 mg deslorelin (≥90% ovulation within 48 hours of treatment). Ovulation rate between 24 and 48 hours was highest when the FD at treatment was 31-35 mm, as compared to 25-30 mm or 36-40 mm. Repeated use of deslorelin or treatment during different seasons had no effect on induction efficiency. About 70% of ovulations occurred between 32 and 48 hours, and highest incidence of ovulation was at 36-38 hours after induction. In experiment 2, TAI using cooled semen (1 × 109 motile sperm in a 10 mL volume) was performed once at 8 hours after induction (n = 59). Pregnancy rate after TAI with cooled semen was 49.2% (29/59). In experiment 3, jennies were inseminated twice with 10 (n = 23), 5 (n = 31), 3 (n = 32), 2 (n = 82) and 1 (n = 66) straws (more than 50 × 106 motile spermatozoa in each 0.5 mL straw) of frozen semen at 34 and 42 hours after induction. The pregnancy rates were 30.4%, 35.5%, 34.4%, 29.3% and 28.8%, respectively (P > 0.05). MAIN LIMITATIONS: In the frozen semen trial, 22.5% (68/302) jennies were excluded after failure to ovulate during the appropriate time interval. In addition, there were no control groups for the AI trials. CONCLUSION: When FD reaches 31-35 mm, a donkey jenny can be inseminated once using cooled semen at 8 hours or twice using frozen semen at 34 and 42 hours after deslorelin treatment. The frozen semen TAI protocol resulted in acceptable pregnancy rates using 1 × 108 motile spermatozoa per cycle.

Characteristics of follicular dynamics and reproductive hormone profiles during oestrous cycles of jennies over an entire year.

Although donkeys have been domesticated for over 6,000 years, limited information is available concerning their reproductive physiology, especially under intensive rearing conditions. The aims of this experiment were to study follicular dynamics and reproductive hormone variation in jennies during the inter-ovulatory interval in different seasons. A total of 12 continuous cycles of six Dezhou Black (DB) donkey jennies were examined in four different seasons. The diameters of the six largest follicles of each jenny were measured daily by ultrasonography, and blood samples were collected at fixed times for reproductive hormone assays. The results demonstrated that most jennies displayed regular oestrous cycles in all seasons. The follicular dynamics were similar in Spring, Summer and Winter, while the jennies had longer oestrous cycles with delayed follicular deviation and dominant selection in Autumn. At least two follicular waves were observed in each oestrous cycle, throughout the study, but two jennies presented oestrous cycles with three follicular waves in the Autumn. The numbers of follicular waves were consistent with the numbers of FSH surges. Oestrous characteristics of the jennies in a large herd were also analysed. The results showed that the rates of regular oestrous cycles were 83.1% (265/319), 89.6% (215/240), 80.2% (235/293) and 77.1% (178/231), with 26.4% (70/265), 19.5% (42/215), 22.1% (52/235) and 23.0% (41/178) double ovulation rates in Spring, Summer, Autumn and Winter, respectively. The results presented may be useful for donkey farms in the design of breeding strategies.

Strongly coupled magnon-phonon dynamics in a single nanomagnet.

Polaritons are widely investigated quasiparticles with fundamental and technological significance due to their unique properties. They have been studied most extensively in semiconductors when photons interact with various elementary excitations. However, other strongly coupled excitations demonstrate similar dynamics. Specifically, when magnon and phonon modes are coupled, a hybridized magnon-phonon quasiparticle can form. Here, we report on the direct observation of coupled magnon-phonon dynamics within a single thin nickel nanomagnet. We develop an analytic description to model the dynamics in two dimensions, enabling us to isolate the parameters influencing the frequency splitting. Furthermore, we demonstrate tuning of the magnon-phonon interaction into the strong coupling regime via the orientation of the applied magnetic field.

MicroRNA­223 promotes hepatocellular carcinoma cell resistance to sorafenib by targeting FBW7.

Hepatocellular carcinoma (HCC) is a globally prevalent malignancy associated with a poor patient prognosis. We investigated the relationship between microRNA­223 (miR­223) expression and the sensitivity of HCC cells to sorafenib treatment. miR­223 expression was determined in HCC cell lines with differential sorafenib sensitivity using reverse transcription­quantitative PCR. miR­223 inhibitor, miR­223 mimic, and F­box and WD repeat domain­containing 7 (FBW7) short interfering RNAs (siRNAs) were transfected into the HCC cells to regulate the expression levels of miR­223 and FBW7. Cell proliferation was evaluated using an ethynyl deoxyuridine (EdU) incorporation assay and Cell Counting Kit­8. FBW7 protein expression levels were observed using western blotting. miR­223 expression was increased in the HCC cells with sorafenib resistance. HCC cells with miR­223 knockdown had significantly increased sorafenib sensitivity, but the miR­223 mimic had the opposite effect. The TargetScan web server predicted that FBW7 is a target of miR­223, which was confirmed by western blotting. Furthermore, FBW7 siRNA transfection increased HCC cell resistance to sorafenib in an obvious manner, and entirely eliminated the effect of the miR­223 inhibitor on enhancing sorafenib sensitivity. To conclude, miR­223 expression is upregulated in sorafenib­resistant HCC cells, and miR­223 knockdown significantly enhances HCC cell sensitivity to sorafenib by increasing expression of the target gene, FBW7, suggesting that miR­223 may be a new therapeutic target for overcoming sorafenib resistance.

Effects of Transgenic Bt Rice Containing the Cry1Ab Protein on the Gastrointestinal Health of Highly Inbred Wuzhishan Pigs after Two Generations of Feeding.

To assess the safety of transgenic Bt rice, we evaluated the chronic effects of Bt rice carrying the Cry1Ab protein (1.64 mg/kg) on the gut microbiota and histopathology in highly inbred Wuzhishan pigs (WZSP) in a two-generation feeding study. The WZSP of the f0 ( n = 26) and f1 ( n = 27) generations were divided into GM and Non-GM groups and fed for 360 and 420 days with Bt and isogenic parent-line rice, respectively. The high-throughput 16S rRNA gene sequencing results revealed that the relative abundance of the family Enterobacteriaceae and genus Escherichia were significantly different between f1F and f1Z. The level of the genera CF231 and SMB53 in the f0Z group was higher than that in the f0F group. In addition, no abnormal histopathology changes in the main gastrointestinal tissues were found after feeding with Bt rice. In conclusion, Bt rice consumption has no adverse effects on the gut microbiota or organ function of WZSP.

Intracellular calcium chelating agent (BAPTA-AM) aids stallion semen cooling and freezing-thawing.

This study aimed to investigate the effects of different concentrations of 1,2-bis-(o-aminophenoxy)-ethane-N,N,N0 N0-tetraacetic acid, tetra-acetoxymethyl ester (BAPTA-AM), an intracellular calcium chelating agent, on stallion semen cooling and freezing-thawing. After collection, semen was extended (1:1 v/v) on a skim milk-based extender, centrifuged and resuspended at 400 million/ml into cooling or freezing extenders containing 0, 5, 25, 50, 100 and 200 µΜ BAPTA-AM. Motility parameters were assessed after cooling in Equitainer at 5°C for 12, 24, 48, 72 and 120 hr and after freezing-thawing. In addition, mitochondrial membrane potential, intracellular ATP, reactive oxygen species and malondialdehyde concentrations were measured in cryopreserved-thawed semen. Cooled stored (48 hr) semen containing 50 µΜ BAPTA-AM and control extender (0 µΜ BAPTA-AM) was used to assess fertility. Inclusion of 50 µΜ BAPTA-AM resulted in superior sperm motility parameters during cooled storage when compared to other groups (p < 0.05). Furthermore, semen cryopreserved in extender containing 50 µΜ BAPTA-AM showed increased intracellular ATP and mitochondrial membrane potential, whereas reactive oxygen species and malondialdehyde were increased after thawing for all groups (p < 0.05). Addition of 50 µΜ BAPTA-AM to cooling extender resulted in similar pregnancy rates to the control group (75% vs. 73.6%, respectively; p > 0.05). In conclusion, the addition of BAPTA-AM to semen extenders aided stallion semen cryopreservation in a dose-dependent manner. Furthermore, the cooling extender supplemented with 50 µΜ BAPTA-AM could be used to prolong the sperm motility during cooling without apparently compromising fertility. Field trials should be conducted to assess fertility of cryopreserved stallion semen with BAPTA-AM.

Effects of 60-Week Feeding Diet Containing Bt Rice Expressing the Cry1Ab Protein on the Offspring of Inbred Wuzhishan Pigs Fed the Same Diet.

We evaluated the chronic effects of Bt rice carrying the Cry1Ab protein (1.64 mg/kg) on offspring of highly inbred WZSP, fed with Bt rice for 360 days, in a 60-week feeding study. The WZSP offspring (n = 27) were assigned to two groups (Minghui86 group, female n = 6, male n = 5; Bt group, female n = 11, male n = 5). The average obtained Cry1Ab protein dosage for female and male pigs was 1.003 and 1.234 mg/kg body weight after 10 weeks of feeding, respectively. The experimental feed in the study was nutritionally matched in both groups. The average daily gain and feed conversion ratio of the females in week 3 and males from weeks 1 to 10 were different between the Bt and Minghui86 groups (P < 0.05), and the body weight of the male pigs in week 2 was greater in the Minghui86 group than that of the Bt group (P < 0.05). No other differences were observed, and there were no significant differences in the serum sex steroid level, hematology parameters, relative organ weights, or histopathology. Although differences in some serum chemistry parameters (alanine aminotransferase of female pigs and alkaline phosphatase of male pigs) were observed, they were not considered treatment-related. On the basis of these results, long-term intake of transgenic rice carrying Cry1Ab protein exerts no unintended adverse effects on WZSP offspring.