Effect of insemination timing on pregnancy outcome in association with female age, sperm motility, sperm morphology and sperm concentration in intrauterine insemination.

AIM: We investigated the effect of insemination timing on pregnancy outcomes in intrauterine insemination (IUI) cycles. METHODS: This is a retrospective study of 411 IUI cycles performed with a diagnosis of unexplained infertility and male factor infertility. The cycles were divided according to the interval between insemination and ovulation: ≤36 h, 36-37 h, 37-38 h and >38 h. The overall pregnancy rate, chemical pregnancy rate and clinical pregnancy rate were compared. We also analyzed the association between pregnancy outcomes and clinical characteristics, including age, duration of infertility, sperm concentration, body mass index (BMI), anti-Müllerian hormone (AMH) and number of mature follicles at ovulation. RESULTS: There were no differences regarding age, duration of infertility, BMI, AMH, sperm concentration and number of mature follicles between different IUI timing groups. Sperm morphology was significantly lower in ≤36 h group (5.3 ± 1.4) compared to 36-37 h, 37-38 h and >38 h (6.3 ± 2.5 vs 6.5 ± 2.7 vs 6.5 ± 3.5, P = 0.004) groups. The ≤36 h group showed lowest total pregnancy rate (5.0%) compared to other IUI timings (21.8% vs 24.8% vs 20.0%, P = 0.05). Multivariate analysis showed that sperm morphology was associated with pregnancy in 36-37 h (odd ratio 1.42, 95% confidence interval 1.03-1.95, P = 0.02). CONCLUSION: Insemination at least 36 h after ovulation is associated with increased pregnancy rate compared to IUIs performed ≤36 h following ovulation.

Quantifying sperm egg interaction to assess the breeding efficiency through artificial insemination in guinea fowls.

1. Guinea fowl hens were inseminated weekly once with two doses of spermatozoa (75 million and 100 million) in two different diluents, Beltsville poultry semen extender (BPSE), and Instruments for Veterinary Medicine (IMV), each with and without pre-insemination vaginal douching. Per cent fertility, hatchability, dead germ, dead in shells along with data on sperm egg interaction and vaginal microbial counts were recorded. 2. Artificial insemination had significantly improved the per cent fertility and hatchability compared to natural mating. Dose dependent improvement in fertility was noticed with both diluents. 3. There was a beneficial effect of vaginal douching, which was more pronounced at lower insemination doses. 4. For optimum fertility and hatchability in guinea fowl, insemination of 75 million spermatozoa diluted in BPSE once in 4 d and 100 million spermatozoa diluted in BPSE or IMV once in 5 d coupled with vaginal douching is recommended.

Chicks produced in the Magellanic penguin (Spheniscus magellanicus) after cloacal insemination of frozen-thawed semen.

The in vitro and in vivo functionality of cryopreserved spermatozoa was examined over two breeding seasons in a zoological colony of Magellanic penguins (Spheniscus magellanicus). Frozen-thawed semen was inseminated into five anesthetized females, over a total of eight egg production cycles, with a different male used for each artificial insemination (AI) within each season. Females were maintained within the colony in cordoned nest sites to prevent copulation with their paired male, and were inseminated every 3-10 days until the first oviposition. Semen frozen from seven males using a straw method retained 39.8%, 25.7%, 74.0%, and 52.1% of its initial total motility, progressive motility, average path velocity, and plasma membrane integrity, respectively. Normal morphology of motile cells was reduced (P < 0.05) during freeze-thawing from 76.7% immediately prior to freezing to 65.3% post-thawing. Conceptive females received 1.6 ± 0.2 inseminations before the first oviposition, with 19.2 ± 1.6 × 10(6) motile, morphologically normal spermatozoa per insemination. Overall fertility was 53.3% (8/15 eggs), hatchability was 50.0% (4/8), and genetic analyses confirmed that all embryos and hatchlings were sired by the AI male. Fertile eggs were laid at 4.0-12.1 days after AI, indicating that frozen-thawed spermatozoa resided in the female reproductive tract for up to ∼7.2 days prior to fertilization. Results demonstrate that frozen-thawed Magellanic penguin spermatozoa are fully functional in vivo and support the use of genome banking and AI as tools for managing the sustainability of zoological penguin populations. Zoo Biol. 35:326-338, 2016. © 2016 Wiley Periodicals, Inc.

[Mexican National Consensus on Assisted Reproduction Treatment]. / Consenso Nacional Mexicano de Reproducción Asistida.

BACKGROUND: It is estimated that 15% of couples living in industrialized countries are infertile, ie have failed to conceive, reproductive age, after 12 months ormore of regular intercourse without contraception. During the past decade has increased the demand for fertility treatments because they believe are moreeffective now. OBJECTIVE: To unify the therapeutic approach and service to patients and set a precedent for a Mexican Official Standard respect and support for the legislation of these procedures. METHOD: Consensus by technical experts group panel with the participation of 34 national centers accredited for use in assisted reproduction. He organized seven workshops with the following themes: 1) selection of patients for assisted reproduction treatment, 2) schemes controlled ovarian stimulation for assisted reproduction techniques of high complexity, 3) preparation and egg retrieval technique, 4) transferembryo; 5) luteal phase supplementation; 6) indications and techniques of cryopreservation and 7) informed consent. Each table had a coordinator who wrote and presented the findings to the full, it made a number of observations until they reached unanimity of criteria, which are reflected in this document. RESULTS: Patient selection for assisted reproduction techniques is the first step of the process. Proper selection lead to success, in the same way that a bad pick up for failure. In the case of egg donation the most important recommendation is that only one to two embryos transferred in order to reduce multiple pregnancy rates and maintaining high pregnancy rates.

Patient and hospital characteristics associated with variation in guideline adherence in intrauterine insemination care.

OBJECTIVE: To assess the association of patient and hospital characteristics with adherence to guidelines for intrauterine insemination (IUI) care. DESIGN: Retrospective cohort study using multilevel regression analysis. Characteristics studied at the patient level were female age, type and duration of subfertility, diagnosis and number of started IUI cycles. At the hospital level, the characteristics studied were hospital size, teaching hospital, in vitro fertilization (IVF) licence and number of physicians involved in the IUI programme. Data were obtained from medical records and questionnaires for gynaecologists. SETTING AND PARTICIPANTS: Five hundred and fifty-eight subfertile couples who underwent IUI treatment at 10 Dutch hospitals. MAIN OUTCOME MEASURES: Adherence to systematically developed guideline-based performance indicators describing 20 processes of IUI care. RESULTS: A total of 558 couples who started 2,334 IUI cycles participated. Guideline adherence in IUI care was often substandard and varied considerably between hospitals. Variation in guideline adherence in IUI care was associated with the patient characteristics 'diagnosis' and 'female age'. Only adherence to the guideline recommendation regarding 'screening for tubal occlusion' was associated with hospital characteristics ('hospital size' and 'IVF licence'). Large explained variances up to 39% were found for the different models. CONCLUSIONS: A number of patient and hospital characteristics were associated with variation in guideline adherence in IUI care, particularly the patient characteristics 'diagnosis' and 'female age'. The identification of different subgroups in the patient population and different types of hospitals with regard to the extent of guideline adherence in IUI care is important for the tailoring of interventions to improve IUI care.

Comparison of the efficacy of treating sperm with low hypoosmotic swelling test scores with chymotrypsin followed by intrauterine insemination vs in vitro fertilization with intracytoplasmic sperm injection.

PURPOSE: To compare the efficacy of two treatments for sperm with low hypoosmotic swelling (HOS) test scores - intrauterine insemination (IUI) with sperm pretreated with the protein digestive enzyme chymotrypsin versus in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI). METHODS: The choice of patient therapy was optional. The pregnancy rates following two IUI cycles vs one IVF cycle with ICSI were then compared. The data were further stratified and compared according to the severity of the HOS score defect. RESULTS: The more severe the HOS test defect the less likely for chymotrypsin therapy to work whereas the severity did not affect IVF with ICSI success. The use of IVF with ICSI was much more effective than IUI with chymotrypsin treatment. CONCLUSIONS: Though IVF with ICSI is much more effective, IUI is much less expensive. Couples should be presented with these data and be allowed to make their own choice considering risks and expense versus efficacy and speed of success.

Effect of climate factors on conception rate of lactating dairy cows in Mexico.

The purpose of this study was to investigate the relationship between conception rate (CR) and climate variables. Data consisted of 24,380 inseminations of Holstein dairy herd in Hidalgo, Mexico. Weather records, including daily temperature (T), relative humidity (RH), rainfall, wind speed, and solar radiation, were obtained from a nearby weather station. Means for each climatic variable from 2 days before artificial insemination (AI) to the AI day were calculated for each conception date represented in the study. A significant negative correlation was observed between the CR and mean and minimum T, mean and minimum RH, mean and minimum temperature-humidity index (THI), and rainfall. The overall mean CR was 34.3%. The CR in lactating dairy cows followed a seasonal pattern, lower CRs were observed in summer months than during winter (32.1% vs. 36.9%; P<0.01). The variables that had the greatest influence on CR were minimum and maximum T, minimum RH, minimum THI, wind speed, and rainfall.

Optimal lead follicle size for human chorionic gonadotropin trigger in clomiphene citrate and intrauterine insemination cycles: an analysis of 1,676 treatment cycles.

OBJECTIVE: To identify the optimal lead follicle size for hCG trigger in clomiphene citrate (CC)-intrauterine insemination (IUI) cycles. DESIGN: Retrospective cohort study. SETTING: University-affiliated center. PATIENT(S): Patients <40 years of age with ovulatory dysfunction or unexplained infertility undergoing their first CC-IUI cycle. INTERVENTION(S): Ovulation induction, hCG trigger, and IUI. MAIN OUTCOME MEASURE(S): Clinical pregnancy rate (CPR) was the primary outcome and was plotted against lead follicle size in increments of 1 mm. Odds ratios with 95% confidence intervals for associations between lead follicle size and CPR were calculated from a multivariable logistic regression model. A receiver operating characteristic (ROC) curve was generated for CPR as a function of lead follicle size. RESULT(S): 1,676 cycles were included. The overall CPR was 13.8% (232/1,676). There was no difference in baseline demographics or ovulation induction parameters of patients who did or did not conceive. The odds of clinical pregnancy were 2.3 and 2.2 times higher with lead follicle sizes of 21.1-22.0 mm and >22.0 mm, respectively, compared with the referent category of 19.1-20.0 mm. Lead follicle size was an independent predictor of CPR, even after accounting for confounders. A lead follicle size of 22.1 mm corresponded to a sensitivity and specificity of 80.1% and 90.4% for clinical pregnancy, respectively, with an area under the ROC curve of 0.89. CONCLUSION(S): hCG administration at a lead follicle size of 21.1-22.0 mm is associated with higher odds of clinical pregnancy in patients undergoing their first CC-IUI cycles for ovulatory dysfunction or unexplained infertility.

Seminal plasma proteins do not consistently improve fertility after cervical insemination of ewes with non-sorted or sex-sorted frozen-thawed ram spermatozoa.

The effect of supplementation of sex-sorted and non-sorted spermatozoa with seminal plasma protein (SPP) on fertility after cervical insemination was examined in the present study. Spermatozoa were sorted into high purity X and Y chromosome-bearing spermatozoa or not sorted and then either supplemented with SPP (>10 kDa) before freezing and/or after thawing (non-sorted only) or processed without supplementation. Inseminations were performed over 2 days with ewes receiving 100 or 25 million motile non-sorted spermatozoa in the cervix or uterus, respectively, or two cervical inseminations of 3.5 million motile sorted spermatozoa. Pregnancy rates in cervically inseminated ewes were unaffected by supplementation of sorted or non-sorted spermatozoa with SPP before freezing compared with no supplementation. The effect of post-thaw supplementation of non-sorted spermatozoa with SPP on pregnancy rates after cervical insemination varied with the day of insemination (P < 0.05); fertility was similar to laparoscopic insemination on Day 1 (56.0 +/- 10.2% v. 58.6 +/- 10.1%), but not on Day 2 (23.1 +/- 7.4% v. 66.7 +/- 9.2%). In conclusion, under the conditions of the present study, SPP did not consistently improve pregnancy rates after cervical insemination with frozen-thawed ram spermatozoa. This is the first report of pregnancies (5/56 ewes inseminated) after cervical insemination with frozen-thawed sex-sorted ram spermatozoa. Although the success rate is low, the findings are encouraging because ewes inseminated with the sex-sorted spermatozoa received only 7% of the recommended dose (100 million motile) for cervical insemination of frozen-thawed spermatozoa.

Digestibility, fecal characteristics, and plasma glucose and urea in dogs fed a commercial dog food once or three times daily.

Digestibility, fecal characteristics, and levels of glucose and urea in the plasma were determined in 8 dogs that received 2 different dog foods once or 3 times daily. One dog food (A) was 5 times more expensive than the other (B). Fecal pH and consistency, digestibility of dry matter (DM), organic matter (OM), crude protein (CP), and crude fiber (CF) were determined. Blood samples were taken from 30 min before to 60 min after a meal. Digestibilities of DM, OM, and CP, and fecal consistency were higher, and daily fecal excretion and fecal pH were lower when dogs were fed food A (P < 0.001). The feeding schedule had no effect on plasma glucose and urea. Neither feeding X frequency nor food 3 frequency interactions was significant for the parameters studied.

Synchronization and resynchronization strategies to improve fertility in dairy buffaloes.

Dairy buffalo has an integral role in the sustenance of economics due to its substantial contribution in milk and meat industry, however, the reproduction in this species is challenging. During the last decade, our laboratory conducted a series of experiments to encapsulate the solutions of the problems through optimizing pre- and post-insemination interventions in dairy buffaloes. In an unique study, we proposed that timing of ovulation with reference to the onset of standing heat during spontaneous estrus is delayed, and subsequently re-framed the traditional AM-PM rule (AI after 12 h of standing heat) to AM-AM or PM-PM (AI after 24 h of standing heat) to achieve the optimum fertility using frozen thawed semen in dairy buffaloes. Pregnancy per AI (P/AI) varied substantially either via injecting single shot of prostaglandin (PG) F2α to perform AI at detected estrus or applying standard ovsynch protocol for timed AI (TAI) in buffaloes. However, estrus response, and P/AI remained similar either with used or new controlled internal drug release device in dairy buffaloes. Additionally, the incorporation of estradiol benzoate in progesterone (P4) based protocol resulted in controlled emergence of follicular wave and increased the estrus intensity in buffaloes. Thereafter, we fine-tuned P4-based protocols to optimize the ovulation window for TAI either using GnRH or human chorionic gonadotropin (hCG) or equine chorionic gonadotropin that ultimately improved the fertility in dairy buffaloes. Although, these hormonal interventions resulted in decent fertility, yet it was consistently being compromised due to early or late embryonic losses in dairy buffaloes. Administration of hCG or GnRH on d 7 or 23 or 25 post AI has been proved beneficial to enhance the embryonic survival in buffaloes. Recently, resynchronization program as an aggressive reproductive management approach has been tested that served as a dual-purpose tool to increase overall herd fertility and reduce embryonic losses at commercial buffalo farm operations. Taken together, we concluded that the solutions to the problems of reproductive function are now clearly available with acceptable fertility, however, their application to the small holder buffalo farming remains challenging.

Local α1-adrenergic blockers: An alternative for sheep cervix dilation?

To facilitate transcervical artificial insemination in sheep, the effects of local treatment with α1-adrenergic receptor antagonists on cervix dilation and hemodynamics were evaluated. Ewes (n = 7) were subjected to oestrous synchronisation every 40 days and assigned to treatments in a Latin square experimental design (seven animals × seven periods) with a factorial treatment arrangement (A × B), Factors A (prazosin or tamsulosin) and B (1, 2, or 4 mg/animal). Ewes of the six treatment groups (P1, P2, P4, T1, T2, and T4) were administered α1-adrenergic receptor antagonists while those of the control group (CG) were administered only α1-adrenergic antagonist carrier agent. Distance that the transcervical catheter penetrated without cervical resistance, mean arterial pressure, and uterine artery dopplerfluxometry were evaluated before and after 30 min, 1, 2, 4, 8, and 10 h of treatment. Catheter penetration distance was greater in ewes of the T4 and P4 groups (P < 0.01), with there being a positive correlation between dose and distance (r = 0.243). The penetration distance was similar (P = 0.84) for treated groups, with the greatest penetration occurring 2, 4, and 6 h after treatment (P < 0.01). The passage into the uterine lumen was greater (P = 0.013) in ewes of the P4 (17.9 %) and T4 (19.6 %) groups. There were no effects on blood pressure or uterine blood flow (P> 0.05). These preliminary results indicate there are benefits of treatment with 4 mg/animal of tamsulosin or prazosin in catheter passage through the sheep cervix 2-6 h after administration without hemodynamic effects.

Antibiotics and their alternatives in Artificial Breeding in livestock.

Antibiotics are mandatory components of semen extenders for the control of bacterial contamination and growth. The increasing rate of worldwide resistance to conventional antibiotics in semen preservation media requires the development of new antimicrobial alternatives. This review provides an update on this topic and also highlights the improvement of hygiene in Artificial Insemination centers in order to prevent the development of bacterial resistance. Ideas are shared on future diagnostic tools for bacterial contamination in Artificial Breeding. Finally, new methods to remove or reduce bacteria in semen will be discussed.

Temporal trends in bull semen quality: a comparative model for human health?

INTRODUCTION: A decline in human semen quality over the past 30-60 years has been reported in numerous epidemiological studies from the United States and Europe. We evaluated temporal trends in semen quality parameters in dairy bulls. The long-term management of dairy bulls for artificial insemination presented a unique opportunity to evaluate temporal trends in semen quality and explore this relationship as a potential animal model for reproductive abnormalities in humans. MATERIALS AND METHODS: Bull semen analysis data from 1965 through 1995 were collected from a large artificial insemination organization. Semen analyses from 12- to 18-month-old Holstein dairy bulls were included in the study and consisted of daily sperm concentration, daily ejaculate volume, total daily sperm output, percentage of sperm with normal morphology, and percentage of sperm with normal post-thaw motility. Multiple regression analysis, logistic regression, and general linear modeling were used to determine temporal trends over the 30-year period. RESULTS AND DISCUSSION: Semen quality appears to have declined from 1970 to 1980 or 1985 as manifested by declines in daily ejaculate volume, daily sperm concentration, and total daily sperm output. In contrast, sperm morphology and motility improved over the same period. In approximately 1980 or 1985, depending on the parameter, ejaculate volume, sperm concentration, total sperm, and motility improved. However, normal morphology began to deteriorate during this same period. Methodological inconsistencies over time introduce uncertainty in analyses of temporal trends in semen quality in this and previous human studies. However, changes in technology do not appear to be solely responsible for the temporal trends observed. The source of the decline in semen quality in the bulls studied is unknown. If the decline in semen quality were due to exposure to endocrine disrupting chemicals, then a continued decline or a leveling-off would be expected. Instead, a rise in semen quality was observed during the latter portion of the observation period.

Effect of interval to resynchronization of ovulation on fertility of lactating Holstein cows when using transrectal ultrasonography or a pregnancy-associated glycoprotein enzyme-linked immunosorbent assay to diagnose pregnancy status.

The objective of this study was to compare 2 strategies for resynchronization of ovulation based on nonpregnant diagnoses using transrectal ultrasonography or a pregnancy-associated glycoprotein (PAG) ELISA. Lactating Holstein cows (n = 1,038) were submitted for first postpartum timed artificial insemination (TAI) using a Presynch + Ovsynch protocol. After the initial breeding, cows were randomly assigned to initiate resynchronization 25 d (D25) or 32 d (D32) later. Pregnancy status of cows initiating Resynch 25 d after TAI was determined 27 d after TAI by using a PAG ELISA, whereas pregnancy status of cows initiating Resynch 32 d after TAI was determined 39 d after TAI using transrectal ultrasonography. Cows diagnosed as not pregnant continued the Resynch protocol by receiving an injection of PGF(2 alpha) 7 d after the initial GnRH injection and a second GnRH injection 54 h after the PGF(2 alpha) injection. Cows in both treatments were inseminated approximately 16 h after the second GnRH injection. Blood samples for analysis of progesterone (P(4)) were collected at the first GnRH injection of each Resynch protocol. Pregnancies per AI (P/AI) of nonpregnant cows initiating Resynch 25 vs. 32 d after first postpartum TAI did not differ 39 d after TAI and were 28.3 vs. 30.9% for D25 vs. D32 cows, respectively. Mean P(4) at the first GnRH injection of Resynch was greater for D32 than for D25 cows (3.67 +/- 0.22 vs. 2.83 +/- 0.22 ng/mL), indicating that the Resynch treatments were initiated at different stages of the estrous cycle. After blocking P(4) concentration into low (<1.0 ng/mL) or high (>or=1.0 ng/mL) classes, P(4) class was not found to affect P/AI 39 d after TAI. Early resynchronization was not found to affect P/AI 39 d after TAI; however, early resynchronization did decrease days between inseminations and the interval from the initial nonpregnant diagnosis to conception. Earlier detection of nonpregnant cows using the PAG ELISA in conjunction with a TAI resynchronization program may improve the rate at which cows become pregnant in a dairy herd compared with transrectal ultrasonography conducted at a later stage after TAI.

Inseminating fresh or cryopreserved semen for maximum efficiency: implications for gene banks and industry.

Developing gene bank germplasm collections for animal genetic resources requires establishing germplasm collection goals, that consider capturing the genetic diversity of the population in question and the amount of germplasm required for its reconstitution or other purposes, or both. Computing collection goals for chickens is complicated, compared with mammalian species, due to the multiple chances a single insemination of semen has to fertilize an egg. To address this issue, fertility data were used in conjunction with econometric procedures for determining production efficiency and diminishing returns. Experimental treatments consisted of inseminating fresh semen intravaginally (FIV), frozen-thawed semen inseminated intramagnally (FTIM), and frozen-thawed semen inseminated intravaginally (FTIV). Analysis revealed that the maximum efficiency for a single insemination was at postinsemination d 6, 8, and 3 for FIV, FTIM, and FTIV, respectively. But, additional benefit from a single insemination can be garnered by continuing to collect and incubate eggs to d 11, 17, and 11 for FIV, FTIM, and FTIV, respectively. By extending the insemination interval, the number of fertile eggs can be increased by 62 (FIV), 62 (FTIM), and 48% (FTIV). The ramifications of these results are profound when placed in the context of germplasm collection for gene banks. By using the FTIM treatment, the number of germplasm samples needed to secure a chicken breed, at the 150% level, can be reduced from the FAO projection of 2,454 to 386 straws (0.5 mL). Such a change represents a substantial reduction in collection, processing, and storage costs for gene banks. For industry, the results suggest that extending the time interval between inseminations will yield more fertile eggs and create opportunities to increase the number of hens mated to a rooster.

Evaluation of glycerol removal techniques, cryoprotectants, and insemination methods for cryopreserving rooster sperm with implications of regeneration of breed or line or both.

A series of experiments was designed to evaluate the quality of cryopreserved rooster sperm and its fertility so that programs needing to bank germplasm and recreate animals can do so utilizing a minimal amount of cryopreserved semen. In experiment 1, rooster semen from the National Animal Germplasm Program genebank was thawed and glycerol was removed using a discontinuous Accudenz column or by stepwise dilution. The postthaw sperm motilities, plasma membrane integrity, and concentration were determined before and after deglycerolization. Line differences in postthaw sperm concentration and progressive motility were observed before deglycerolization (P<0.05). After glycerol removal, the sperm that was centrifuged through Accudenz had greater total motility (37 vs. 33% sperm; P<0.05), but use of the stepwise dilution method recovered more sperm per milliliter (320.4x10(6)) compared with the Accudenz method (239.2x10(6) sperm; P<0.05; range across 6 lines of 165.7 to 581.0x10(6) sperm/mL). In experiment 2, rooster semen was cryopreserved using Lake's diluent containing either dimethyl acetamide (DMA) or glycerol as the cryoprotectants. Postthaw analysis revealed that the samples cryopreserved with glycerol survived freezing better, determined by total motility (47.8 and 15.1% glycerol and DMA samples, respectively; P<0.05) and annexin V analyses (1.6 and 11.3% membrane-damaged sperm for glycerol and DMA samples, respectively; P<0.05). Differences in sperm motilities (total and progressive motility) and velocities (path velocity, straight-line velocity, curvilinear velocity) were observed between the 2 cryoprotectant treatments once the glycerol had been removed from those samples cryopreserved with glycerol, of which the glycerol samples had significantly more motile sperm and higher velocities (P<0.05). The fertility of the samples frozen using the 2 cryoprotectants was tested using a single insemination (intravaginal or intramagnal) of 200x10(6) sperm and the fertility (number of live embryos) was evaluated over 18 d. Overall, the intravaginal inseminations had lower fertility than the intramagnal inseminations (P<0.05). In the intravaginal inseminations, the sperm cryopreserved using DMA resulted in lower fertility, but there were no differences in fertility in the intramagnal inseminations due to cryoprotectant (P>0.05). These results indicate that reasonable postthaw sperm quality and fertility can be derived using cryopreserved rooster semen. By utilizing this information, estimations can be made for storing sufficient material for line or breed, or both, recreation programs.

Effects of increased levels of supplemental vitamins during the summer in a commercial artificial insemination boar stud.

Heat stress due to increasing extremes in ambient temperature and humidity results in reduced semen quality in boars. This has caused reduced efficiency of the swine industry, requiring more boars to breed the same number of sows. Vitamins such as vitamin C (VC) and E (VE) have been shown to improve semen quality in boars. Recently, vitamin D has been shown to improve semen quality in boars. The purpose of this experiment was to evaluate the effects of increased supplemental vitamins on boar reproduction during the summer season in a commercial boar stud. One hundred and sixty Pig Improvement Company (PIC) terminal line boars (n = 32 per treatment) and 39 maternal, heat-sensitive boars (n = 7 or 8 per treatment) were randomly allocated to treatment and fed a corn and soybean meal-based diet adjusted based on individual boar body condition score. A control (CNT) diet was used that met PIC recommendations for boars. Increased supplementation of specific vitamins was given in the form of a top-dress and consisted of CNT wheat middlings, CNT plus VC (560 mg/day), CNT plus 25-hydroxy vitamin D3 (VD) (125 µg/day), CNT plus VE (275 mg/day) and CNT plus VC, VD and VE (CDE). The experiment was split into three periods based on maximum daily high temperatures in the barn, where period 1 was weeks 1 to 4, period 2 was weeks 5 to 11 and period 3 was weeks 12 to 14. Semen was collected from boars as needed using the stud's normal production schedule and was analyzed for sperm quantity and quality characteristics. There were no dietary effects on semen volume, sperm concentration or total sperm production (P ≥ 0.553). Total motility of sperm was not impacted by diet (P = 0.115); although, VC tended (P = 0.064) to have a greater progressive motility than CDE. Percentages of morphologically normal sperm and normal acrosomes were not affected by dietary supplementation (P ≥ 0.157). Period effects were observed for most semen quality parameters, with quality generally becoming reduced over time. The present study demonstrates that increased supplementation of vitamins beyond PIC recommendations was not beneficial for boar reproduction during the summer.

Efficacy of Heatsynch protocol for induction of estrus, synchronization of ovulation and timed artificial insemination in yaks (Poephagus grunniens L.).

The objective of this study was to test the efficacy of induction of estrus, synchronization of ovulation and timed artificial insemination in anestrous yaks using the Heatsynch protocol. In Experiment 1, 10 anestrous yaks were administered an analogue of gonadotropin releasing hormone (GnRH) followed by prostaglandin (PG)F2alpha 7 days later and then estradiol cyponate (ECP) 24 h after that. Ovulation was detected by rectal palpation at 2h intervals beginning at the initial signs of estrus. Blood samples were collected at 2h intervals beginning at the time of ECP injection up to 2h after the occurrence of ovulation for the determination of LH and progesterone. All the animals responded to the Heatsynch protocol with expression of estrus and synchronization of ovulation. The mean time interval from the ECP injection to ovulation was 59.4+/-2.62 h (range 50-72 h). The interval from the LH peak to ovulation was 30.2+/-2.3 h. The high degree of synchrony in ovulation could be attributed to the synchrony in the timing of LH peaks. In Experiment 2, 10 anestrous yaks were treated with the Heatsynch protocol (as in Experiment 1) and TAI was performed at 48 and 60 h after the ECP treatment. Concurrently, 16 cycling yaks were inseminated approximately 12 h after detection of spontaneous estrus. Pregnancy rates were similar in both groups, 40% for TAI and 43.75% for yaks inseminated following spontaneous estrus (p>0.05). From this study, two conclusions can be drawn. First, the Heatsynch protocol can be successfully used to induce and synchronize estrus in anestrous yaks and, second, ovulation following the Heatsynch protocol is synchronized adequately to permit the use of fixed time AI in this species.

The use of embryo transfer to produce pregnancies in repeat-breeding dairy cattle.

Repeat breeding is an important factor affecting economic success in dairy management. The objective of this study was to investigate the effectiveness of transfer of frozen-thawed IVF embryos in establishing pregnancy in repeat-breeding Holstein cattle. Cumulus oocyte complexes were collected by aspiration of 2-5 mm follicles from ovaries obtained at two local abattoirs. After IVF, days 7 and 8 blastocysts were frozen either in 1.5M ethylene glycol with 0.1M sucrose, or in 1.4M glycerol with 0.1M sucrose. Holstein recipients (122 heifers and 410 cows) included those that had not conceived after 3-21 inseminations. Embryos frozen in ethylene glycol were transferred directly, and embryos frozen in glycerol were transferred after dilution of the cryoprotectant in sucrose into recipients 7 or 8 days after estrus (without-AI group), or following AI (with-AI group). Pregnancy rates were compared by the Chi-square test. Significantly higher pregnancy rates were achieved by embryo transfer following AI (with-AI group) than by embryo transfer alone (without-AI group) in both heifers (49.2 and 29.5%, respectively) and cows (41.5 and 20.4%, respectively; P<0.05). Pregnancy rates were not significantly different between heifers and cows. However, pregnancy rate decreased as the number of inseminations prior to embryo transfer increased in the with-AI group, but not in the without-AI group. Therefore, transfer of frozen-thawed IVF embryos during the same cycle in which AI was done improved pregnancy rates in repeat-breeding Holstein heifers and cows, and suggested that embryo transfer is an alternative in the treatment of repeat breeding.