Stimulation of Estrus and Ovulation by Resynchronization in Kangal Sheep during Early Anestrus.

A total of 100 Kangal sheep were divided into four groups with the aim of investigating the effectiveness of resynchronization during anestrus for the first time in the literature. The groups were then divided into two further subgroups, namely the resynchronization subgroup group (hCG+resynch) and group (resynch)) and the no resynchronization subgroup (Group (hCG) and group (control)). All the groups started with progesterone-containing sponge insertion on Day 7. The sponge was removed after 7 days (on Day 0), and 600 IU eCG + 131.5 µg PGF2α was injected. The animals in group (hCG+resynch) and group (hCG) received hCG injection at the time of sponge administration. Accordingly, four different groups were established, i.e., resynchronization + hCG administration group (hCG+resynch); n:25), no resynchronization + hCG administration (group (hCG); n:25), resynchronization + no hCG administration (group (resynch); n:25), and no resynchronization + no hCG administration (Group (control); n:25). Estrus rates at the first application in group (hCG+resynch), group (hCG), group (resynch), and group (control) groups were 76%, 88%, 96%, and 76%, respectively, and pregnancy rates were 52%, 64%, 72%, and 60%, respectively; there were no intergroup statistical differences in the two parameters above. It was concluded that resynchronization performed with two consecutive stimulations during anestrus could help save time and provide a pregnancy rate at a level that can provide economic returns.

The influence of L-proline and fulvic acid on oxidative stress and semen quality of buffalo bull semen following cryopreservation.

BACKGROUND: This study investigates the effects of cryopreservation and supplementation of Azeri water buffalo's semen with proline (Lp) and fulvic acid (FA). OBJECTIVES: Therefore, this study aimed to assess motility parameters, sperm viability, oxidative stress parameters, and DNA damage to detect the optimum concentrations of Lp and FA for buffalo semen cryopreservation. METHODS: Thirty semen samples of three buffalo bulls were diluted in Tris-egg yolk extender and divided into 12 equal groups including control (C), Lp-10, Lp-20, Lp-40, Lp-60, Lp-80 (containing 10, 20, 40, 60, 80 mM L-proline, respectively), FA-0.2, FA-0.5, FA-0.8, FA-1.1, FA-1.4 and FA-1.7 (containing 0.2%, 0.5%, 0.8%, 1.1%, 1.4% and 1.7% fulvic acid, respectively). RESULTS: The velocity parameters, TM and PM were improved by FA-1.7, FA-1.4, Lp-40 and Lp-60 groups compared to the C group but no significant difference was found regarding the amplitude of lateral head displacement and straightness compared to the control groups. The percentage of sperm viability and PMF were increased by FA-1.7, FA-1.4, FA-1.1, Lp-40 and Lp-60 groups compared to C group, while in terms of sperm DNA damage FA-1.7, FA-1.4, FA-1.1, Lp-10, Lp-20, Lp-40 and Lp-60 groups showed better results compared to C group. The results also showed that FA-1.7, FA-1.4, FA-1.1, Lp-20, Lp-40 and Lp-60 groups could improve TAC, SOD, GSH and decrease MDA levels. Also, FA-1.7, FA-1.4, Lp-20 and Lp-40 groups could improve GPx levels but just FA-1.7, and Lp-40 groups could improve CAT levels compared to C group. CONCLUSIONS: Thus, it can be concluded that L-proline and fulvic acid supplementations can improve the quality parameters of post-thawed buffalo bull semen.

The effect of different FSH administration before ovum pick up on superstimulation response and oocyte yield.

This study aims to evaluate the effect of synchronization and different superstimulation protocols on oocyte yield before ovum-pick up (OPU) to provide a homogeneous follicle population. Animals in all study groups except the control group applied a synchronization protocol including modified ovsynch+progesterone and dominant follicle ablation (DFA, on the 6th day following synchronization). In group 1, oocytes were retrieved by ultrasonography only on the 4th day after DFA. In group 2, 250 µg pFSH (100 µg IM, 150 µg SC) was administered as a single dose on the 2nd day following DFA, and oocytes were retrieved on the 2nd day following this injection. In group 3, 250 µg pFSH was administered IM in four equal doses 12 h apart on the 1st and 2nd days following DFA, and oocytes were retrieved 2 days after the last FSH injection. In group 4, 250 µg pFSH (IM) dissolved in Montanide ISA 206 adjuvant was administered as a single dose on the 2nd day following DFA, and oocytes were retrieved 2 days after this treatment. In the control group (group 5), oocytes were retrieved from animals without any hormonal treatment on a random day of the oestrus cycle. In order to assess the follicle population in the ovary on the day of OPU, the number of follicles according to their diameter was determined by ultrasonography in all groups. The ratio of medium-sized follicles (3-8 mm) was higher in the synchronized groups (Groups 1, 2, 3 and 4) than in the control group (Group 5) (p < .05). It was determined that the total number of oocytes obtained after OPU and the number of oocytes of suitable quality (Grade A and B) in in vitro embryo production were higher in the superstimulated groups (Groups 2, 3 and 4) compared to the control group. It was found that the number of Grade-A quality oocytes was higher in the superstimulated groups (Groups 2, 3 and 4) than the other groups. As a result, it was found that the synchronization and superstimulation treatments prior to the OPU increased the ratio of medium-sized follicles and the total number of oocytes obtained. In addition to the synchronization protocol, it was determined that superstimulation treatments increased the oocyte quality obtained with OPU. Furthermore, it was observed that a single dose of FSH dissolved in Montanide ISA 206 adjuvant produced a superstimulation response similar to that produced by repeated doses of FSH.

The effect of double-dose GnRH injections on reproductive performance parameters following short-term progestagen administration in lactated Awassi ewes during the non-breeding season.

The present study was aimed to investigate the effects of double-dose gonadotropin-releasing hormone (GnRH) injection on the induction of oestrus and some reproductive performance parameters in Awassi ewes during the non-breeding season. In the study, 100 ewes were treated with a vaginal sponge containing 60 mg medroxyprogesterone acetate for 7 days in the anoestrus (day 0). PMSG 500 IU and 250 µg cloprostenol sodium were injected on the day of removal of the sponge (day 7). Ewes in Group 1 (n = 31) were not subjected to any hormonal treatment. Ewes in Group 2 (n = 31) were given 50 µg GnRH 48th hour after removal of the sponge. Ewes in Group 3 (n = 33) were given 50 µg GnRH 48th hour after the removal of the sponge and 50 µg GnRH 12th day after post-mating. The results obtained in the study showed that there were no statistical differences between the Groups 1, 2 and 3 in terms of oestrus rates (82.8%, 68.9%, 72.7%), conception rates (66.7%, 55.0%, 54.2%), multiple pregnancy rates (28.5%, 50.0%, 30.7%) and litter sizes (1.28, 1.50, 1.31). No significant increases in P4 concentration were observed in Group 3 treated with GnRH at the 12th day after post-mating; however, a numerically lower (p > 0.05) late embryonic-early fetal mortality rate was observed in Group 3 (0%), when compared with the values obtained in Group 1 (12.5%) and Group 2 (9.1%). In conclusion, after short-term progestagen administration during the non-breeding season, double-dose GnRH injections did not increase P4 concentration and had no significant differences on reproductive performance parameters among groups.

Protein based flushing related blood urea nitrogen effects on ovarian response, embryo recovery and embryo quality in superovulated ewes.

The present study is the first report that evaluates effects of nutritional effects of flushing with differing diet crude protein ratios on blood urea nitrogen (BUN) levels, related some reproductive parameters and embryo quality in ewe. During mating season, before synchronization protocol ewes were fed on alfalfa hay and additive concentrate feeding as flushing. Intra vaginal FGA containing sponges applied for 12 days for the purpose of synchronization and pFSH was administered by 8 declining doses for the purpose of superovulation. Uterus was flushed in the morning of the seventh day of mating and embryos were collected surgically. Collected embryos were qualified according to IETS criterion. There is no dependency found between BUN values measured at different days and at different diet crude protein concentrations. An increase in uterine pH levels due to increasing protein amounts was observed but this increase was not significant among groups. Ovarian function was evaluated by ovarian responses (CL + large follicle) showed difference between groups (p < 0.05) and the lowest protein intake group gave highest ovarian response. In addition, embryo recovery rates revealed difference between groups (p < 0.05) and it was observed that the lowest ovarian response group showed the highest rates of embryo recovery. It is concluded that, in some Anatolian native sheep breeds, the application of diet flushing with different crude protein concentrates influence ovarian responses and embryo recovery rates but has no effect on BUN levels; uterus physiology or embryonic quality.

Expression of wingless type (WNT) genes and their antagonists at mRNA levels in equine endometrium during the estrous cycle and early pregnancy.

WNT signaling pathway plays important roles in reproductive events. Aims were to (1) determine presence of WNT genes and their antagonists in equine endometrium; and (2) to evaluate their expression profiles during early pregnancy. Endometrial biopsies were obtained from mares on day of ovulation (d0, n=4) and on days of 14 (P14, n=4), 18 (P18, n=4), 22 (P22, n=4) of early pregnancy. Biopsies were also collected from cyclic mares during late diestrus (LD, on day of 13.5-14, n=4) and after luteolysis in estrus phase (AL, on day of 17.5-18, n=4) of the cycle. PCR was used to detect expression of genes studied and then relative expression levels were quantified using real-time PCR analysis. A mixed model was fitted on the normalized data and least significant difference test (α=0.05) was employed. Eleven WNT genes (WNT2, WNT2B, WNT4, WNT5A, WNT5B, WNT7A, WNT8A, WNT9B, WNT10B, WNT11 and WNT16) and their antagonists (SFRP1, SFRP2, SFRP5, DKK1, DKK2 and WIF-1) were detected in equine endometrium. Compared to d0, WNT2, WNT5B, WNT7A and SFRP1 expressions were downregulated by the pregnancy while DKK1 was upregulated. WNT5A, WNT11 and WIF-1 were upregulated on P14 and P18, but WNT2B increased only on P14. When LD and P14 were compared, level of WNT8A decreased on P14 while increase in WNT4 level on P14 was slightly significant (P<0.06). Levels of WNT7A and SFRP1 decreased while DKK1 and WIF-1 increased by the pregnancy on P18 compared to AL. Moreover, WNT2B, WNT5A, WNT9B, WNT10B, WNT11, WNT16 DKK1 and WIF-1 were upregulated on LD compared to AL whereas WNT4, WNT7A, SFRP1 were downregulated. In conclusion, the results demonstrate that WNT genes and their antagonists appear to be regulated during early pregnancy in equine endometrium possibly due to embryonic factors and/or maternal progesterone.