Increasing vitamin D levels to improve fertilization rates in cattle.

Recently, interest in supplementing vitamin D (Vit D) to improve aspects of health, mainly in human fertility, has emerged. Still, supplementation of Vit D above the minimum required levels has yet to be explored in cattle despite evidence for Vit D receptors in reproductive tissues. The objective of this study was to establish if a dose-response relationship exists between Vit D exposure and success of in vitro production (IVP) of embryos and, if acute supplementation of Vit D improves pregnancy rates during timed artificial insemination (TAI) of dairy cows. Cumulus-oocyte complexes (COCs) were obtained from ovaries acquired from a local abattoir and cultured in five different IVP treatments from three separate collections (Control, 50, 100, 150, and 200 ng/mL of 1,25(OH)2D3; n = 20-30 COCs/group). In Experiment 2, dairy breed cows (n = 100) were synchronized for TAI with the PresynchOvsynch protocol. Cows received 150,000 IU of Vit D (n = 48) or castor oil as control (n = 53) along with gonadotropin-releasing hormone (GnRH) 24 h before TAI. Serum samples were collected before and 24 h after treatment. A small cohort of cows (n = 4) received the same treatments in two separate cycles and follicular fluid (FF) was collected after 24 h for calcidiol (25OHD) analyses. Increased concentrations of Vit D resulted in decreased rates of maturation of COC (150 and 200 ng/mL vs. control and 50 ng/mL; P = 0.01). Supplementation with 50 ng/mL resulted in greater numbers of early blastocyst and blastocyst stage embryos (P < 0.009). Pregnancy at first breeding did not differ (P = 0.13) between groups, but serum 25OHD increased in treated females after 24 h (P = 0.002). The FF 25OHD levels were reflective of serum levels, however, the observed increase in the treatment cycle (P = 0.04) was parallel to an overall increase in serum 25OHD during the entire second cycle, likely due to increased environmental sunlight exposure (March, control vs. May, treatment). A similar increase in the serum 25OHD in the lactating commercial herd maintained in covered housing was not observed, although experiments were conducted during a similar timeframe. This herd had levels of 25OHD near the low end of sufficiency according to National Research Council (NRC) guidelines. We conclude mild Vitamin D supplementation with concentrations at the higher end of NRC guidelines can improve maturation rates of recovered COCs. However, longer term supplementation may be needed to appreciate any benefits on fertility.

Vitamin D is an important hormone that among other things, contributes to bone health, immunity, and reproduction. Recently, research has linked vitamin D to fertility in other species (primates), and therefore the objectives of the current research were to determine if mild supplementation with Vitamin D impacted fertility in female cattle. A dose-dependent relationship was detected between concentrations of vitamin D and embryo development. The concentration of 50 ng/mL of vitamin D appeared to be beneficial to early embryogenesis. Studies in dairy-breed females indicated serum levels of vitamin D correlated well with intrafollicular levels in the periovulatory follicle. Finally, a fertility trial investigated if a single dose of vitamin D improves fertility when administered before artificial insemination in cattle. There were no detectable benefits to this brief supplementation with vitamin D on measures of fertility in this group. It is concluded supplementation with vitamin D improves embryo development in vitro, but brief supplementation did not impact pregnancy success. Longer-term supplementation with vitamin D may be needed to appreciate any measurable benefits on fertility.

Progesterone supplementation to improve fertility of selected subgroups of lactating cows during the summer and fall.

One major cause of low fertility of cows in the summer is progesterone deficiency. We found that insertion of a controlled intravaginal drug-releasing (CIDR) device containing progesterone after artificial insemination (AI) increases pregnancy per AI (P/AI) in cows with uterine disease and low body condition score after calving. Here, we treated only these two subgroups, during the summer and autumn. Control (n = 191 AI) and treatment (n = 230 AI) cows were inseminated at estrus and the treated group received a CIDR device on day 5 post-AI, for 14 days. Overall analysis of data during the summer and autumn indicated no significant differences between treatment and control groups. Analysis of the summer data only indicated a significant effect of treatment: P/AI was higher in CIDR-treated vs. control groups (34.2% vs. 19.3%; p < .038). Results indicated a 15% increase in P/AI during the summer for CIDR-treated cows in subgroups that had responded positively to the progesterone treatment.

Effects of boar sperm antioxidant supplementation on fertility.

Use of cooled stored boar semen for artificial insemination accounts for 99% of inseminations in pork production sectors worldwide. The aim of the present study was to examine use of GameteGuard®-CP, a natural plant derived blend of antioxidants, supplemented in one commercially available semen extender on sperm quality, conception rate, farrowing rate, and litter size. Ejaculates from 16 commercial Duroc boars were used in a split-ejaculate single-sire artificial insemination study. Sperm were evaluated for motility, viability, acrosome integrity, membrane stability, mitochondrial membrane potential, DNA intactness, and total antioxidant reactivity on both day 1 and 4 subsequent to ejaculate collection. Sows were inseminated after a treatment regimen was imposed to synchronize time of ovulation (n = 1476) among females using sperm collected 4 days subsequent to ejaculate collection extended in AndroStar Plus® or GameteGuard®-CP supplemented extender. At day 4 post-ejaculate collection, there was maintenance of sperm viability, membrane stability, acrosome intactness, mitochondrial membrane potential, and DNA intactness (P < 0.01) when there was use of GameteGuard®-CP treatments. When control samples were used, there were lesser (P < 0.01) values from day 1-4 for all variables evaluated. Conception rate and farrowing rates were 7.4% and 9.7% greater, respectively (P < 0.05), but there was no difference as a result of GameteGuard®-CP-treatment in mean litter outcomes. The results in the present study indicate antioxidant supplementation using GameteGuard®-CP maintains sperm quality during cool sperm storage resulting in improved conception and farrowing rates when using semen stored in the cooled state for as long as 4 days.

Parenteral Copper Administration at the Beginning of a Fixed-Time Artificial Insemination Protocol in Beef Cattle: Effect on Ovarian Function and Pregnancy Rates.

The aim of this study was to evaluate the association between plasma copper (Cu) concentration and ovarian function during a fixed-time artificial insemination (FTAI) protocol and the effect of parenteral Cu administration (100 mg) at the start of such protocol (day 0) on area of preovulatory follicle (APF); area of corpus luteum (ACL), plasma estradiol (E2), and progesterone (P4) concentrations; CL blood flow (CLBF); and pregnancy rate in beef heifers and cows. In cows, plasma Cu concentration on days 0 and 7 correlated positively with APF. Copper administration increased plasma Cu concentration and decreased APF and plasma E2 concentration (day 9), without modifying ACL, plasma P4 concentration, and CLBF (day 16) in cows. Pregnancy rate was higher in Cu-supplemented cattle on day 41 after FTAI as compared with controls (58.76 and 45.28%, respectively). In conclusion, Cu administration at the beginning of the FTAI protocol increased pregnancy rate in beef heifers and cows, modifying APF and plasma E2 concentration in the latter.

Consultation and treatment behaviour of infertile couples in China: a population-based study.

RESEARCH QUESTION: The prevalence of infertility in couples actively trying to conceive is 25%. What is the consultation-seeking behaviour, diagnosis and related treatment in infertile couples across China? DESIGN: Large cross-sectional population-based study in 2010-2011, in which 25,270 couples from eight provinces/municipalities in China were approached by a multistage stratified cluster sampling strategy. RESULTS: Among the 2680 couples reporting infertility, 1246 infertile couples consulted a fertility doctor. Age of the couple, man's body mass index and women's educational level were found to be associated with consultation behaviour. After the fertility work-up, diagnoses were tubal infertility (n = 353, 28.3%), unexplained infertility (n = 311, 25.0%), male infertility (n = 234, 18.8%), ovulatory disorder (n = 194, 15.6%) and endometriosis (n = 34, 2.7%), while 8.6% (n = 107) were not classified. Most couples received non-assisted reproductive technology (ART) fertility treatment (n = 906, 89.3%), with a proportion using traditional Chinese medicine (TCM) (n = 298, 29.4%). Intrauterine insemination (n = 62, 6.1%) and IVF/intracytoplasmic sperm injection (n = 57, 5.6%) were less frequent. Medical treatment and outcomes among five subtypes of infertility were also reported: about 30% of couples with unexplained infertility (n = 94, 30.3%) or male infertility (n = 67, 29.0%) used TCM to treat infertility. Apart from patients with endometriosis, of whom 20.6% (n = 7) received ART, patients with other infertility subtypes rarely received ART. For subsequent fertility outcome, 94% of them did not achieve a pregnancy. CONCLUSION: The prevalence of infertility in China is high, but the uptake of treatment is relatively low.

Deep insemination with sex-sorted Cashmere goat sperm processed in the presence of antioxidants.

Flow cytometrically sex-sorted sperm have been widely used for improving reproductive management in the dairy industry. However, the industrial application of this technology in other domestic species is largely limited by the lower fertility after insemination. The aim of this study was to investigate effects of antioxidant supplementation during the sex-sorting and freezing process on the quality and functions of sorted sperm from Liaoning Cashmere goats. We tested the effects of antioxidant supplementation during sex-sorting and freezing process, including ascorbic acid-2-glucoside AA-2G, glutathione, melatonin and vitamin C (VC), on the quality and functions of sex-sorted fresh and frozen-thawed sperm. Based on these experiments, we performed deep insemination with sex-sorted sperm using our improved strategy, in comparison to unsorted sperm. In Experiment 1, compared with control group and other antioxidants, AA-2G supplementation significantly alleviated the degradation of motility and viability of fresh sperm after sorting and showed the highest percentage of sperm with normal morphology. In addition, AA-2G supplementation showed an evident protection against the sorting process-induced membrane and acrosome damage. In Experiment 2, AA-2G supplementation was most effective in protecting motility, while melatonin supplementation appears to facilitate the degradation of quality of frozen-thawed sex-sorted sperm. In Experiment 3, we performed deep insemination with sperm that were sorted and frozen in the presence of AA-2G and obtained a satisfying pregnancy rate comparable to that from unsorted sperm. The results showed that AA-2G supplementation efficiently protects quality and function of both fresh and frozen-thawed sex-sorted sperm of Cashmere goats, thus obtaining a satisfying pregnancy outcome.

L-Carnitine in rooster semen cryopreservation: Flow cytometric, biochemical and motion findings for frozen-thawed sperm.

Rooster semen cryopreservation is not efficient for artificial insemination in breeder flocks. L-Carnitine (LC) has been evaluated for effectiveness in cryopreservation media on the characteristics of rooster sperm after freeze-thawing. Motility characteristics, membrane functionality, abnormal morphology, apoptotic like changes, mitochondria activity and lipid peroxidation of rooster sperms were assessed after freeze-thawing with different concentrations of LC in Beltsville medium. Semen samples were collected from 12 roosters, twice a week, and diluted in the extenders that contained different concentrations of LC. Supplementation of Beltsevile with 1 and 2 mM LC was found to result in higher total motility (68.2± 1.7% and 69.1± 1.7%, respectively), progressive motility (28.4± 1.6%, 29.8± 1.6%), membrane functionality (76.2± 1.9% and 75.9± 1.9%), viability (58.2 ± 1.1%, 59.1 ± 1.1%) and lower significant of lipid peroxidation (2.53 ± 0.08 nmol/ml, 2.49 ± 0.08 nmol/ml) compared to control group containing no LC. Lower motility, progressive motility, and viability were observed in frozen-thawed sperm in extender containing 8 mM LC (35.8± 1.7%, 9.6± 1.2% and 27.1 ± 1.2%, respectively) compared to control. Morphology and mitochondrial activity were not affected by different concentrations of LC. Our results showed that supplementation of Beltsville extender with 1 and 2 mM LC significantly improved the quality of rooster sperm quality after freeze-thawing.

Fertility response of artificial insemination methods in sheep with fresh and frozen-thawed semen.

The aim of this study was to evaluate the fertility response of artificial insemination (AI) methods with fresh and frozen sperm in sheep. In experiment 1, one hundred and fifty fat tailed Zandi ewes were assigned into 3 equal groups and inseminated with three AI methods consisting of vaginal, laparoscopic and trans-cervical AI with fresh semen. In experiment 2, a factorial study (3 AI methods × 2 extenders) was used to analyze the effects of three AI methods and two freezing extenders containing soybean lecithin (SL) or Egg yolk (EY) on reproductive performance of 300 fat tailed Zandi ewes. Also, total motility, progressive motility, viability and lipid peroxidation of semen were evaluated after freeze-thawing in two extenders. In result, there was no significant difference among three AI methods when fresh semen was used. In experiment 2, the highest percentage of pregnancy rate, parturition rate and lambing rate were obtained in laparoscopic AI group (P < 0.05). Although pregnancy rate, parturition rate and lambing rate in trans-cervical group were higher (P < 0.05) than vaginal group, the results were not as high as laparoscopic group. No difference was observed between SL and EY extenders and their performance was close to each other. It can be concluded that although no difference was observed on reproductive performance for fresh semen, trans-cervical AI was more efficient than vaginal method when frozen-thawed semen was used, but its efficiency was not as high as laparoscopic method. Also, SL extender can be an efficient alternative extender to preserve ram sperm during cryopreservation procedure without adverse effects of EY.

The use of coenzyme Q10 and DHEA during IUI and IVF cycles in patients with decreased ovarian reserve.

OBJECTIVE: The objective of this study is to compare the combination of dehydroepiandrosterone (DHEA) and coenzyme Q10 (CoQ10) (D + C) with DHEA alone (D) in intrauterine insemination (IUI) and in vitro fertilization (IVF) cycles among patients with decreased ovarian reserve. METHODS: We retrospectively extracted data from patients charts treated by DHEA with/without CoQ10 during IUI or IVF between February 2006 and June 2014. Prestimulation parameters included age, BMI, day 3 FSH and antral follicular count (AFC). Ovarian response parameters included total gonadotropins dosage, peak serum estradiol, number of follicles > 16 mm and fertilization rate. Clinical outcomes included clinical and ongoing pregnancy rates. RESULTS: Three hundred and thirty IUI cycles involved D + C compared with 467 cycles of D; 78 IVF cycles involved D + C and 175 D. In both IUI and IVF, AFC was higher with D + C compared with D (7.4 ± 5.7 versus 5.9 ± 4.7, 8.2 ± 6.3 versus 5.2 ± 5, respectively, p < 0.05). D + C resulted in a more follicles > 16 mm during IUI cycles (3.3 ± 2.3 versus 2.9 ± 2.2, respectively, p = 0.01), while lower mean total gonadotropin dosage was administered after D + C supplementation compared with D (3414 ± 1141 IUs versus 3877 ± 1143 IUs respectively, p = 0.032) in IVF cycles. Pregnancy and delivery rates were similar for both IUI and IVF. CONCLUSION: D + C significantly increases AFC and improves ovarian responsiveness during IUI and IVF without a difference in clinical outcome.

Comparative evaluation of Nabi and Beltsville extenders for cryopreservation of rooster semen.

Two experiments were conducted to evaluate the new rooster semen freezing extender which is containing a low level of glycerol and soybean lecithin as an alternative protective agent in the extender. The aim of the first experiment was to evaluate a new extender for freeze-thawing rooster semen known as "Nabi" extender compared to Beltsville. Second experiment was also performed to determine whether the Nabi extender has negative reactions on fertilization after artificial insemination (AI) or no. In the first experiment, post-thaw motion parameters, mitochondrial function and sperm apoptosis were analyzed using Sperm Class Analyzer (SCA), rhodamine-123 and Annexin-V, respectively for frozen-thawed semen in Nabi and Beltsville extender. Results showed that total motility, progressive motility, velocity parameters (VCL, VSL, VAP, LIN and STR) and live spermatozoa with active mitochondria were significantly higher in Nabi compare to Beltsville extender (P < 0.01). Also, the percentages of post-thawed live and early apoptotic spermatozoa were significantly higher in Nabi compared to Beltsville extender (14.46 ± 0.95 vs. 19.27 ± 0.95 and 14.83 ± 4.51 vs. 39.27 ± 4.51, respectively). For apoptotic spermatozoa, the percentages of post-thawed late apoptotic spermatozoa were significantly lower in Nabi (29.66 ± 3.11) compared to Beltsville extender (69.07 ± 3.11), but the type of extender had no effect on the percentages of post-thawed necrotic spermatozoa. In the second experiment, 20 broiler breeder hens (Ross 308) were inseminated with thawed semen using the new freezing diluents or fresh semen for determination of fertility rate. Fertility rate with thawed semen (with Nabi extender) was lower compared to fresh semen (by approximately 8% points). It can be concluded that Nabi extender would improve post-thawed rooster sperm in vitro quality compared to Beltsville extender. The fertility rates of insemination in hens with freeze-thaw sperm were comparable with fresh sperm.

Association between ovarian stimulators with or without intrauterine insemination, and assisted reproductive technologies on multiple births.

OBJECTIVE: We sought to quantify the risk of multiple births associated with the use of different modalities of medically assisted reproduction. STUDY DESIGN: We conducted a case-control study using a birth cohort from 2006 through 2009. This cohort was built with the linkage of data obtained by a self-administered questionnaire and medical, hospital, pharmaceutical, birth, and death databases in Quebec. Cases were pregnancies resulting in multiple live births (International Classification of Diseases, Ninth Revision/International Statistical Classification of Diseases, 10th Revision codes). Each case was matched, on maternal age and year of delivery, with 3 singleton pregnancies (controls) randomly selected among all Quebec singleton pregnancies. Data on the use of different fertility treatments were collected by a self-administered questionnaire. Multiple logistic regression models, adjusted for body mass index, number of previous live births, ethnicity, family income, place of residence, marital status, subfertility, reduction of embryos, diabetes, metformin treatment, folic acid supplementation, and lifestyle factors, were used to calculate the odds ratios (ORs) and confidence intervals (CIs). We evaluated the associations between each type of fertility treatment (ovarian stimulators used alone, intrauterine insemination [IUI] used with ovarian stimulation, and assisted reproductive technologies [ART]) and the risk of multiple births. RESULTS: A total of 1407 cases of multiple births and 3580 controls were analyzed. More than half of multiple births following medically assisted reproduction (53.6%) occurred among women having used ovarian stimulation with or without IUI. The use of ovarian stimulators alone and IUI with ovarian stimulation increase the risk of multiple births (adjusted OR, 4.5; 95% CI, 3.2-6.4; and adjusted OR, 9.32; 95% CI, 5.60-15.50, respectively) compared to spontaneous conception. The use of invasive ART was associated with a greatly increased risk of multiple births. Among only the 465 women who used medically assisted reproduction for conception, the use of IUI with ovarian stimulation was associated with an increased risk of multiple births (adjusted OR, 1.98; 95% CI, 1.12-3.49) when compared to ovarian stimulators used alone. Invasive ART were associated with an increased risk of multiple births (adjusted OR, 6.81; 95% CI, 3.72-12.49) when compared to ovarian stimulators used alone. CONCLUSION: Although the risk of multiple births associated with invasive ART can be decreased by elective implementing of single embryo transfer, special attention should be paid to the greatly increased risk associated with ovarian stimulation used alone or with IUI.

Effect of semen extender supplementation with cysteine on postthaw sperm quality, DNA damage, and fertilizing ability in the common carp (Cyprinus carpio).

Amino acids have an important biological role for prevention of cell damage during cryopreservation. The objective of this study is to determine the effects of cysteine on postthaw sperm motility, duration of sperm motility, DNA damage, and fertility in the common carp (Cyprinus carpio). Sperm collected from 10 individuals was cryopreserved in extenders containing different cysteine concentrations (2.5, 5, 10, and 20 mM). Semen samples diluted at the ratio of 1:9 by the extenders were subjected to cryopreservation. After dilution, the semen was aspirated into 0.25-mL straws; the straws were placed on the tray, frozen in nitrogen vapor, and plunged into liquid nitrogen. DNA damage was evaluated by comet assay after cryopreservation. Our results indicated that an increase in the concentration of cysteine caused a significant increase in the motility rate and duration of sperm in the common carp (C carpio; P < 0.05). Comparing all concentrations of cysteine, the best concentration of cysteine was 20 mM. Higher postthaw motility (76.00 ± 1.00%) and fertilization (97.00 ± 1.73%) rates were obtained with the extender at the concentration of 20 mM. Supplementation of the extender with cysteine was increased the fertilization and hatching rate and decreased DNA damage. Consequently, cysteine affected the motility, fertilization, and DNA damage positively, and extenders could be supplemented with cysteine.

The impact of thyroid function on intrauterine insemination outcome--a retrospective analysis.

BACKGROUND: Hashimoto's thyroiditis is the most common endocrinopathy in premenopausal women, and is associated with various gynecological problems, including recurrent miscarriage and unexplained infertility. A possible influence of Hashimoto's thyroiditis on the success of intrauterine insemination seems likely, but has not been evaluated as yet. Therefore, the aim of our study was to retrospectively analyze the impact on intrauterine insemination outcome of thyroid function and markers suggestive for Hashimoto's thyroiditis. METHODS: Retrospective cohort study in a tertiary care center of 540 women who underwent Intrauterine Insemination. The clinical pregnancy rate was the main outcome parameters. The following possible influencing factors were tested: thyroid-stimulating hormone (TSH); thyroid autoantibodies; age; body mass index; type of sterility (primary/secondary); parity; male factor; presence of PCO syndrome; ovulation induction; ovarian stimulation; and current thyroid medication. RESULTS: The overall clinical pregnancy rate was 6.9% (37/540). Age, thyroid hormone supplementation for thyroid-stimulating hormone (TSH) levels>2.5 micro-IU/ml, and ovulation induction with HCG were significantly predictive in the multivariate analysis (p<0.05) as influencing factors for the pregnancy rate after intrauterine insemination. CONCLUSIONS: Women undergoing intrauterine insemination seem to benefit from a strict thyroid hormone supplementation regimen in order to achieve lower TSH levels.

Extracellular ATP and dibutyryl cAMP enhance the freezability of rat epididymal sperm.

We studied the effects of ATP, ionomycin, and dibutyryl cAMP (dbcAMP) on the motility, freezability, and oxygen consumption of rat epididymal sperm. In vitro fertilization and intrauterine insemination were performed by using frozen-thawed rat sperm. Frozen-thawed sperm diluted in raffinose-modified Krebs-Ringer bicarbonate solution-egg yolk extender containing 1.85 mM ATP and 100 microM dbcAMP exhibited considerably higher motility and viability than sperm diluted in dbcAMP-free extender. Addition of ionomycin and dbcAMP to ATP-containing extenders did not alter the oxygen consumption rate of sperm, suggesting that extracellular ionomycin and dbcAMP are not involved in the mobilization of mitochondrial energy substrates in sperm. Further, high rates of pronucleus formation and progression to the blastocyst stage were observed in embryos produced by the fertilization of oocytes with fresh sperm in an in vitro fertilization medium supplemented with ATP and dbcAMP. Oocytes were not penetrated by frozen-thawed sperm when cocultured with cumulus-oocyte complexes in a medium without ATP and dbcAMP. In contrast, cryopreserved sperm penetrated oocytes when the gametes were cultured in an ATP- and dbcAMP-containing medium, and the resultant embryos formed blastocysts. Our results show that the dilution of rat sperm in raffinose-modified Krebs-Ringer bicarbonate solution-egg yolk extender supplemented with ATP and dbcAMP prior to sperm cryopreservation enhances the freezability of the cryopreserved sperm. Furthermore, the in vitro fertilization medium we developed effectively supports the production of embryos from both fresh and cryopreserved rat sperm.

Perspective on physiological/endocrine and nutritional factors influencing fertility in post-partum dairy cows.

Increasing reproductive performance of post-partum lactating dairy cows is a multi-factorial challenge involving disciplines of production medicine, nutrition, physiology and herd management. Systems of programmed timed insemination have been fine-tuned to achieve pregnancy per artificial inseminations (AI) approximating 45%. Systems have optimized follicle development, integrated follicle development with timing of induced corpus luteum regression and fine-tuned sequential timing of induced ovulation and AI. Use of programmes for insemination have identified occurrence of anovulatory ovarian status, body condition, uterine health and seasonal summer stress as factors contributing to reduced herd fertility. Furthermore, programmes of timed insemination provide a platform to evaluate efficacy of nutritional and herd health systems targeted to the transition and post-partum periods. The homeorhetic periparturient period, as cows deal with decreases in dry matter intake, results in a negative energy balance and is associated with a period of immunosuppression. Cows that transition well will cycle earlier and have a greater risk of becoming pregnant earlier post-partum. The innate arms of the immune system (acute and adaptive) are suppressed during the periparturient period. Cows experiencing the sequential complex of disorders such as dystocia, puerperal metritis, metritis, endometritis and subclinical endometritis are subsequently less fertile. Targeted strategies of providing specific nutraceuticals that provide pro- and anti-inflammatory effects, such as polyunsaturated fatty acids (e.g., linoleic, eicosapentaenoic/docosahexaenoic, conjugated linoleic acid), sequential glycogenic and lipogenic enrichment of diets, and organic selenium appear to differentially regulate and improve the immune and reproductive systems to benefit an earlier restoration of ovarian activity and increased fertility.

Improved fertility in gilts and sows after artificial insemination of frozen-thawed boar semen by supplementation of semen extender with caffeine and CaCl2.

Supplementation of semen extender with caffeine and CaCl(2) for artificial insemination (AI) of fresh spermatozoa has been demonstrated to reduce recruitment of uterine polymorphonuclear leukocytes (PMNs) and the activity of phagocytosis. Here, we determined if addition of caffeine and CaCl(2) to semen extender improves the fertility of frozen-thawed boar semen. In experiment 1, gilts were cervically inseminated twice with frozen-thawed boar spermatozoa (25 x 10(8) cells per dose) suspended in Modena solution (n=7) or modified Beltsville Thawing Solution supplemented with caffeine and CaCl(2) (BCC, n=7). The gilts were slaughtered 4 h later, and their oviducts and uterine horns plus the body of the uterus were flushed to recover PMNs and non-phagocytosed spermatozoa. There was no difference in the total number of uterine PMNs between gilts inseminated with Modena solution and those inseminated with BCC (3.8 x 10(8) vs. 1.5 x 10(8) cells, respectively); however, the total number of uterine spermatozoa was higher when gilts were inseminated with BCC (40.6 x 10(6) cells) compared with those inseminated with Modena solution (1.4 x 10(6) cells, P<0.05). In experiment 2, gilts and sows were subjected to intrauterine insemination twice with frozen-thawed spermatozoa suspended (25 x 10(8) sperm per dose) in Modena (n=21) or BCC (n=21). The overall pregnancy and farrowing rates were higher in females inseminated with BCC (71.4 and 61.9%, respectively) compared with those inseminated with Modena solution (38.1 and 28.6%, respectively, P<0.05). However, no significant difference in litter size of piglets was observed between treatments (7.2 +/- 1.6 piglets for Modena solution vs. 8.2 +/- 0.9 piglets for BCC solution). In conclusion, we demonstrated that use of BCC solution for frozen-thawed boar semen produced better pregnancy and farrowing rates following AI than Modena solution, probably by reducing the phagocytosis of spermatozoa.

Quality of embryos produced from dairy cows fed whole flaxseed and the success of embryo transfer.

The objective of the experiment was to determine the effects of fat supplementation on embryo quality of dairy cows and the subsequent success of embryo transfer into recipient heifers fed the same sources of fat. A total of 30 lactating Holstein cows were allotted on d 18 postpartum to 2 groups of 15 donor cows blocked for similar calving dates. Total mixed diets based on silage and fat supplements were fed for ad libitum intake. On a dry matter basis, diets fed to donor cows contained 7.9% whole flaxseed or 2.8% calcium salts of palm oil and those fed to recipient heifers contained 11.4% whole flaxseed or 4.2% calcium salts of palm oil. The experiment with donor cows was carried out between d 18 and 109 of lactation. The experimental diets were fed to 121 recipient heifers from wk 8 before estrus synchronization and superovulation to d 50 of gestation. Dietary fat fed to donor cows had no effect on the number of viable embryos per cow (3.7 +/- 0.5), the number of degenerated embryos per cow (1.8 +/- 0.4), or the number of unfertilized oocytes per cow (2.1 +/- 0.8). But feeding flaxseed decreased fertilization rate (64.3 vs. 78.4%) and the percentage of grade 1 to 2 embryos (56.5 vs. 74.1%) and increased the embryo degeneration percentage (27.4 vs. 18.2%) compared with feeding calcium salts of palm oil. There was no effect of diets fed to donor cows and those fed to recipient heifers for pregnancy rate of heifers. Supplementation with a rich source of n-3 fatty acids decreased quality of embryos from donor lactating dairy cows compared with feeding calcium salts of palm oil, but had no effect on the subsequent pregnancy rate of heifers receiving frozen grade-1 embryos.

The roles of vitamin A for cytoplasmic maturation of bovine oocytes.

Vitamin A is one of the micronutrients which have been implicated in cattle reproduction. In cattle, ingested vitamin A, mainly as beta-carotene (BC) from forages and retinol ester from formula feed, is metabolized and transported to the oocytes and cumulus-granulosa cells in ovarian follicles through binding to various interacting molecules. The active form of vitamin A, retinoic acid (RA), functions as a regulator of gene expression in these targets. Early research showed the positive effects of vitamin A supplementation on bovine fertility in artificial insemination, and several studies on effects of vitamin A metabolites used in other artificial reproductive techniques (ART), including superovulation, ovum pick up, and in vitro maturation culture have provided evidence for the specific roles of vitamin A in oocyte cytoplasmic maturation (acquisition of developmental competence of oocytes during their meiotic maturation period for the embryonic development after fertilization). BC may enhance cytoplasmic maturation by its antioxidant properties which cannot be replaced by RA. Furthermore, RA may promote cytoplasmic maturation of bovine oocytes via its modulatory effects on the gene expression of gonadotrophin receptors, midkine, cyclooxygenase-2, and nitric oxide synthase in cumulus-granulosa cells.

Fertility following fixed-time AI in CIDR-treated beef heifers given GnRH or estradiol cypionate and fed diets supplemented with flax seed or sunflower seed.

The objectives were to determine pregnancy rates following fixed-time AI (FTAI) in heifers: (1). given GnRH or estradiol cypionate (ECP) to synchronize follicular wave emergence and ovulation in a CIDR-based protocol; and (2). fed diets supplemented with flax or sunflower seeds. At two locations, Angus and crossbred Angus heifers (n=983) were examined ultrasonically to confirm reproductive maturity and randomly allocated to six synchronization groups in a 2 x 3 factorial design. On Day 0 (start of synchronization treatments), heifers received a CIDR and either 100 microg GnRH i.m. (n=492) or 1mg ECP plus 50 mg progesterone i.m. (n=491); in these groups, CIDR removal and PGF treatment were done concurrently on Days 7 and 8.5, respectively. Heifers were re-randomized to receive 0.5 mg ECP i.m. at CIDR removal or 24 h later (with FTAI 58-60 h after CIDR removal in both groups), or 100 microg GnRH i.m. concurrent with FTAI (52-54 h after CIDR removal). The heifers were fed a barley silage-based diet for 50 days (from Day -25 to 25) supplemented with 1kg/heifer per day of flax seed (n=321), sunflower seed (n=324), or no oilseed (n=338). Pregnancy rate to FTAI (overall, 56.2%) was not affected by treatment at CIDR insertion (P = 0.96) but was higher (P < 0.05) in heifers given ECP 24h after CIDR removal (216/330, 65.4%) than in those given either ECP at CIDR removal (168/322, 52.1%) or GnRH at AI (169/331, 51.1%). Overall, there was no effect of diet on pregnancy rates (P = 0.46). In summary, pregnancy rate to FTAI was not significantly affected by treatment at CIDR insertion to synchronize follicular wave emergence, but 0.5mg ECP 24h after CIDR removal (to synchronize ovulation) resulted in the highest pregnancy rate.

Desiccation tolerance of spermatozoa dried at ambient temperature: production of fetal mice.

Long-term preservation of mouse sperm by desiccation is economically and logistically attractive. The current investigation is a feasibility study of the preservation of mouse sperm by convective drying in an inert gas (nitrogen). Mouse sperm from the B6D2F1 strain isolated in an EGTA-supplemented Tris-HCl buffer were dried using three different drying rates and were stored for 18-24 h at 4 degrees C. The mean final moisture content was <5% for all the protocols. After intracytoplasmic sperm injection (ICSI), the mean blastocyst formation rates were 64%, 58%, and 35% using the rapid-, moderate-, and slow-drying protocols, respectively. The slow-drying protocol resulted in a rate of development significantly lower than that observed using rapid- and moderate-drying protocols and indicated that a slower drying rate may be detrimental to the DNA integrity of mouse sperm. The transfer of 85 two- or four-cell embryos that were produced using rapidly desiccated sperm resulted in 11 fetuses (13%) on Day 15 compared with the production of 34 fetuses (40%) produced using the transfer of 86 two- or four-cell embryos that were produced using fresh sperm (P < 0.05). The results demonstrate the feasibility of using a convective drying protocol for the successful desiccation of mouse sperm and identifies some of the important parameters required for optimization of the procedure.