Artificial insemination

Estimados colegas, éste es el primer número de Noticias de Reproducción Bovina, publicación que tiene como propósito ofrecer información para los Médicos Veterinarios Zootecnistas que están trabajando en el manejo reproductivo de hatos bovinos tanto lecheros como de carne. La información contenida proviene de publicaciones científicas periódicas de alto nivel y también de artículos de difusión técnica escritos por especialistas. Aquí podrán encontrar los resúmenes y la referencia para la consulta del artículo completo. La selección de la información está a cargo de los editores y se hace de acuerdo con el criterio de la utilidad práctica de la misma. El objetivo al iniciar con el primer número es ofrecer una publicación bimestral, la cual llegará en forma electrónica a los colegas inscritos en nuestras bases de datos y a todos aquellos que nos escriban solicitándola. Esta es una publicación sin fin de lucro y su único objetivo es ofrecer información actualizada para mejorar el desempeño de los Veterinarios y con ello contribuir al aumento de la productividad de los hatos bovinos de nuestro país.

The dynamics of sperm DNA fragmentation (sDF) and sperm viability were analyzed in frozen-thawed sperm samples of Equus asinus (Zamorano-Leonés), a breed at risk of extinction. Sperm DNA fragmentation was assessed using an adaptation of the sperm chromatin dispersion test developed for stallions in five different frozen samples. Sperm were thawed and incubated at different temperatures (37 8C, 25 8C, and 4 8C) and sDF was assessed at different times and compared. The mean sDF after thawing at the beginning of the experiment was 18.20 AE 14.77% and did not differ significantly from the results of a neutral comet assay (22.0 AE 19.34%). The tendency in the sDF of all donkeys indicated that sperm DNA is more sensitive to breakage when incubated at 37 8C than when incubated at 25 8C or 4 8C. Interestingly, the tendency was not the same when different animals were compared, and differences in sDF dynamics were established among individuals. sDF correlated negatively with sperm viability in some individuals but not in others. From a conservation perspective, sDF analysis may offer a new way to assess sperm quality in endangered breeds in order to identify and select the best semen samples for artificial reproduction purposes. In particular, we recommend for artificial insemination the use of semen samples with a slow increase in sDF with time after thawing. #

The trend of increasing cow numbers per husbandry person makes it difficult to achieve good reproductive management by traditional means. A system to predict the reproductive status of cows would be of great value. There exist time-series models for detecting oestrus from milk traits other than progesterone and decision strategies for interpreting progesterone measures have been suggested but a system combining these aspects to predict not just oestrus but reproductive status throughout the reproductive cycle is lacking. The objective of this study was to develop such a model on the basis of automated milk progesterone sampling.

Currently, timed artificial insemination (TAI) can be applied routinely in the reproductive programs on farms. TAI protocols are designed to promote control of both luteal and follicular function, permitting the TAI with satisfactory pregnancy per AI (P/AI). A variety of protocols for TAI have been designed according to specific characteristics and requirements of different breeds, animal categories and types of management. The most common of these therapies use GnRH or estradiol plus progesterone/progestin (P4)-releasing devices and prostaglandin F2α. Moreover, TAI programs should be considered as an important tool of reproductive management to enhance the reproductive performance of cattle. Thus, the correct incorporation of these programs within the farm routine enhances reproductive efficiency of livestock to increase overall productivity of the farm unit.

Hair sheep ewes (St. Croix White and Barbados Blackbelly) were used to evaluate 3 methods of estrus synchronization for use with transcervical artificial insemination (TAI). To synchronize estrus, ewes (n = 18) were treated with PGF2¢ (15 mg, im) 10 d apart, with controlled internal drug release (CIDR) devices containing 300 mg progesterone for 12 d (n = 18), or with intravaginal sponges containing 500 mg progesterone for 12 d (n = 18). On the day of the second PGF2a injection or at CIDR or sponge removal, sterile rams were placed with the ewes. jugular blood samples were collected from the ewes at 6-h intervals until the time of ovulation, and daily for 16 d after estrus (Day 0). Plasma was harvested and stored at-20°C until LH, and progesterone concentrations were determined by RIA. There was no difference (P > 0.10) in time to estrus among the CIDR-, PGF2c¢-or sponge-treated ewes. All of the ewes in the CIDR group and 94.4% of the sponge treated ewes exhibited estrus by 36 h after ram introduction, while only 72.2% of PGF2a-treated ewes showed signs of estrus by this time (P < 0.06). The time from ram introduction to ovulation was not different (P > 0.10) among the CIDR-, PGF2c¢-or sponge-treated ewes. The time to the preovulatory LH surge was similar (P > 0.10) among CIDR, PGF2c¢ and sponge treated ewes. Progesterone levels through Day 16 after the synchronized estrus were not different (P > 0.10) among treatment groups. Hair sheep ewes (n = 23) were synchronized using PGF2c¢ and bred by TAI using frozenthawed semen 48 h after the second injection. The conception rate to TAI was 2/23 (8.7%) and produced 3 ram lambs. In a subsequent trial, 17 ewes were synchronized with CIDR devices and bred by TAI using frozen-thawed semen 48 h after CIDR removal, resulting in a conception rate of 52.9 % (9/17). It is possible to synchronize estrus in hair sheep using either CIDRs, sponges or PGF2c¢. Even though there were no significant differences in the timing of ovulation Or the LH surge among the treatment groups, a higher conception rate was achieved in ewes synchronized with CIDR devices during the second trial. This may reflect an increase in the skill level of the TAI technidan.

Bacterial, viral and protozoal infections may cause severe reproductive losses. The present paper reviews the risk factors, clinical signs and preventive measures for the most important venereal or potential sexually transmitted diseases in horses. The stallion and use of semen for artificial insemination represent major risk factors for the transmission of bacterial contaminants of the penis, including Streptococcus equi subspecies zooepidemicus, Pseudomonas aeruginosa and Klebsiella pneumoniae, known to cause endometritis and infertility in the mare. The role of the stallion in disease transmission is also due to the non-clinical manifestation of diseases such as contagious equine metritis and equine viral arteritis. Dourine has been eradicated from many countries, but continues to be a problem in other areas of the globe. Strategies for the prevention of introduction and transmission of diseases in breeding operation are discussed.

Within-breed artificial insemination and between-breed embryo transfer were carried out in small pony (P) and large Thoroughbred (Tb) mares to create 4 types of horse pregnancy in which the fetus experienced spatial and nutritional deprivation (Tb-in-P; n=8), luxury (P-in-Tb; n=7) or normality (Tb-in-Tb; n=7 and P-in-P; n=7) in utero. Measurement of equine chorionic gonadotrophin (eCG), total conjugated oestrogens and progestagen concentrations in serial peripheral serum samples recovered from all the mares throughout gestation showed that the amount of eCG produced during the first half of gestation was dependent upon the breed of the mare rather than the breed of the fetus being carried. In contrast, the mean total amounts of oestrogens produced, as measured by area under the curve, were significantly greater (P=0.003) in the two types of pregnancy in which a Thoroughbred fetus was being carried (Tb-in-Tb and Tb-in-P) than those in which a pony fetus was gestated (P-in-P and P-in-...

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 &lt; 0.01). The variables that had the greatest influence on CR were minimum and maximum T, minimum RH, minimum THI, wind speed, and ...

This study was undertaken to determine management and seasonal effects on fertility in 1298 Finnish sow units over a 4-year period in 1992-1996. A multivariate analysis of the herd record data was undertaken to study the effect of various management factors on rebreeding rate. Factors found to have an effect were further subjected to time series plotting for seasonal effects. In addition, seasonal effects on the farrowing rate, age of gilts at first mating and littersize as well as the 3-week litterweight were studied. Year and month caused the most significant variation in the Ž rebreeding rate. Moreover, geographical area, herd and way of breeding mating vs. artificial . insemination were found to be significant determinants of rebreeding rate. Dry sows loosely housed were more likely to be rebred than sows housed in individual stalls. Sows receiving Ž . Ž . roughage feed hay, straw or bedding straw were less likely to require rebreeding. A significant seasonal fluctuation in farrowing rate was found with a nadir of 72.6% in August and a high of 80.9% in January. The average farrowing rate for the 4-year period was 77.7%. The age of gilts at Ž first mating showed seasonal variation of 11 days 229.9 " 0.5 days in March and 241.4 " 0.5 . days in November . In conclusion, this study indicates that group housing of dry sows increases the risk of rebreeding. In group housed sows, rebreeding more often occurs after an irregular oestrus-to-oestrus interval in summer-autumn whereas a not-in-pig seems to be a more common ) Corresponding author.

Sex preselection of livestock offspring in cattle represents, nowadays, a big potential for genetic improvement and market demand satisfaction.Sperm sorting by flow cytometer provides a powerful tool for artificial insemination and production of predefined sexed embryos but, an accurate verification of the yield of sperm separation remains essential for a field application of this technique or for improvement and validation of other related semen sexing technologies.In this work a new method for the determination of the proportion of X- and Y-bearing spermatozoa in bovine semen sample was developed by real time PCR. Two sets of primers and internal TaqMan probes were designed on specific X- and Y-chromosome genes. To allow a direct quantification, a standard reference was established using two plasmid cDNA clones (ratio 1:1) for the specific gene targets. The method was validated by a series of accuracy, repeatability and reproducibility assays and by testing two sets of sorted and unsorted semen samples. A high degree of accuracy (98.9%), repeatability (CV = 2.58%) and reproducibility (CV = 2.57%) was shown.The results of X- and Y-sorted semen samples analysed by real time PCR and by flow cytometric reanalysis showed no significant difference (P > 0.05). The evaluation of X-chromosome bearing sperms content in unsorted samples showed an average of 51.11 ± 0.56% for ejaculates and 50.17 ± 0.58% for the commercial semen. This new method for quantification of the sexual chromosome content in spermatozoa demonstrated to be rapid and reliable, providing a valid support to the sperm sexing technologies.

Data on breeding soundness and libido evaluations in Belgian Blue (BB) bulls are scarce. The present study compared results of breeding soundness and libido evaluations of young BB bulls to young Holstein Friesian (HF) bulls prior to acceptance into an AI program. Breed differences for breeding soundness exist between BB and HF bulls, as 93.7% of the young BB bulls failed the breeding soundness examination (BSE) compared to 59.3% of the HF bulls (P = 0.0005). Within the BB breed, differences were present between bulls of different ages, and bull selection for better fertility with increasing age apparently influenced the results. The number of reasons for which bulls failed the test differed between the age groups in the BB breed, whereas a tendency for more failure reasons in the BB breed was noticed in the breed comparison. The most important reasons for failure were sperm morphology and scrotal circumference (SC), but far more BB bulls failed for these traits compared to the HF breed (82.8% versus 56.0% and 43.8% versus 17.6% in the BB and the HF breed for sperm morphology (P = 0.0005) and SC (P < 0.0001), respectively). The high proportion of BB bulls with a substandard SC and poor sperm morphology might suggest an increased prevalence of testicular hypoplasia or degeneration within this breed. Concerning libido, the reaction time did not differ either between breeds or between age groups within the BB breed, whereas mounting enthusiasm, although not different between the two breeds, did decline with increasing age, probably due to the greater mating experience of the older bulls. All in all, libido did not seem to be different between the breeds.

Since the production of the first live offspring from sex-sorted spermatozoa in 1989, there have been many developments in the fluorescence-activated cell separation (FACS) procedures to preselect Xand Y-chromosome bearing spermatozoa prior to insemination. During this time, FACS technology has been applied to a range of species and has resulted in offspring from rabbits, cattle, sheep, elk and horses. In horses, satisfactory fertility rates have been achieved after hysteroscopic insemination of 20 × 10 6 fresh or stored, sex-sorted spermatozoa. However, many of the sperm processing protocols are still based on the original protocol and components of these procedures may not necessarily be suitable for the stallion. This review examines the details of FACS protocols that have resulted in the production of live offspring and makes comparisons with the published stallion protocols in an attempt to determine how best to improve the fertility of sorted, frozen-thawed stallion spermatozoa.

The aim of the present study was to identify the deletion/insertion polymorphism of the bovine prion protein gene (PRNP) within the promoter sequence (23 bp), intron 1 (12 bp) and 3’ untranslated region (14 bp). DNA was isolated from blood of 234 randomly tested Polish Holstein-Friesian cows and from semen of 47 sires used for artificial insemination (AI) in 2004. No statistically significant differences were found in the frequency of genotypes and alleles between cows and breeding bulls in the 3 analysed polymorphic sites within thePRNP gene. Only 3 haplotypes were identified in sires and 4 haplotypes in cows.

Transcervical embryo collection is used routinely in the bovine species throughout the world to collect Day 6 to Day 9 embryos (early embryos) for genetic selection. For research purposes, however, the collection of embryos at later stages of pregnancy, i.e., Days 12 to 21 (late embryos), is needed. So far, for the recovery of late embryos, females are euthanized and embryo collection is performed after recovery of the genital tract. To reduce the number of animals used and still provide valuable material for embryo research, we have therefore developed a transcervical technique to collect late embryos. The objective of this study was to compare embryo recovery results at early and late stages within our laboratory. Altogether, 232 cows were used for this study. One hundred forty-five flushes were performed to collect embryos from Days 6 to 9, and 251 flushes were performed to collect embryos from Days 12 to 21. For the early embryos, a classical three-way collection equipment was used. To collect the late embryos, the same equipment was used, but the extensible flexible catheter that goes inside the external rigid catheter was removed, so that larger embryos could be collected through the remaining larger hole (two-way collection). All females were submitted to ovum pick up to remove the dominant follicle and were subsequently superovulated with FSH. Luteolysis was induced 48 hours before artificial insemination. Two artificial inseminations were performed with frozen semen, 48 and 56 hours after PGF2a injection. Before embryo collection, cows were treated with an epidural injection of a local anesthetic drug. The presence of CL was checked, and they were counted by rectal palpation. For all collections, the cervix was prepared with the initial introduction of a dilator. Then, the catheter was introduced in one horn, and the cuff was inflated as low as possible. For the collection of late embryos, the flushing solution (30 mL) was injected slowly twice to suspend the embryos before flushing the horn with 500 mL, and the same operation was performed on the second horn. There was no significant difference in the number of embryos collected per flush in the early-and latestage (758 embryos collected, 5.22 AE 6.02 per flush vs. 1238 embryos collected, 4.93 AE 5.07 per flush, respectively). The number of embryos collected per CL, however, was significantly lower in the early versus late group (0.39 AE 0.32% vs. 0.44 AE 0.34%, respectively). The late collection allowed the retrieval of full conceptuses (embryonic and extraembryonic tissues), even at very late stages such as Days 18 to 21. Careful collection is needed, however, so that conceptuses are not damaged or torn: the horn must be * Corresponding author. Tel.: þ33 1 34 65 24 19; fax: þ33 1 34 65 23 64. Theriogenology xxx (2015) 1-9 massaged gently and the flush should be ideally recovered in one single flow. This technique is a powerful tool to collect the late-stage embryos for research purposes. Because it is not traumatic, animals can be used again for the same procedure.

Most of the world's bovine herd is found in tropical regions. Bos indicus predominates, due to their adaptation to the climate and management conditions. Anestrous is the main factor that negatively affects reproductive performance of animals bred in these regions of the globe. Several factors affect postpartum anestrous, including suckling and maternal-offspring bond, and pre-and postpartum nutritional status. The short duration of estrus and the tendency to show estrus during the night, greatly affect the efficiency of artificial insemination (AI) programs in B. indicus cattle managed in tropical areas. Several restricted suckling or weaning procedures (temporary or permanent), and hormonal treatments have been used to induce ovulation and cyclicity in postpartum cows. Most hormonal treatments are based on progesterone/progestogen (P4) releasing devices associated with estradiol benzoate (EB), or a combination of GnRH/PGF 2␣ /GnRH (Ovsynch). Treatments with GnRH/PGF 2␣ /GnRH has presented inconsistent results, probably due to the variable number of cows in anestrous. Treatments using P4 devices and EB have resulted in apparently more consistent results than Ovsynch programs in B. indicus cattle; however, pregnancy rates are low in herds presenting high anestrous rates and moderate to low body condition. The addition of an eCG treatment at the time of device removal, which increased plasma progesterone concentrations and pregnancy rates in anestrous postpartum suckled B. indicus cows, may be useful to improve reproductive performance of beef cattle in tropical climates.

of modem European agriculture, especially in extensive management systems, leads to an increase in the number of animals per stockman. Thus, the time allocated to each animal by the farmer is decreasing. In extensive management systems animals are often fed by their mothers and receive only neutral or aversive contacts from humans (e.g. sanitary treatment). Many welfare problems related to interactions between the animals and their caretakers can arise when changing from intensive management systems to such extensive environments. Management methods and selection of the appropriate animals are being studied to minimise handling problems and the negative consequences for the handlers and the animals.

The liberalization of European animal breeding legislation and an increasing diversity of equestrian sports have led to a constant rise in the number of horse breeds and breed registries. In addition to the trend towards more and smaller breed registries, there is another trend towards an international expansion of the bigger established sport horse breeds. Regional breeds, at least in smaller countries, may no longer be able to run an independent breeding programme. The typical horse breeder, in the future, will be a female and qualified in equestrian sports. Artificial insemination (AI) mainly with fresh or cooled-transported semen has become a major breeding tool, allowing breeders all over Europe to benefit from the best stallions of most breeds. New AI techniques such as low-dose insemination may remain restricted to individual stallions and also the interest of breeding programmes in sex determination of foals via semen sorting is limited. Embryo transfer and associated techniques, although allowed by most breeds, have not contributed significantly to genetic progress in European sport horses so far. A potential use of cloning may be to produce gonad-intact copies from geldings that have performed to a superior level. With a more open and international structure of horse breeding and increased use of AI, equine reproduction and biotechnology should be emphasized by veterinary curricula and continuing professional education programmes.

Aim: This study aimed to investigate the protective effect of Rosmarinus officinalis (L.) essential oil on rooster sperm motility during 4°C short-term storage. Materials and Methods: R. officinalis essential oil was analyzed using gas chromatography coupled to mass spectrometry to identify the active components. 10 of 45-week-old Hubbard commercial broilers were subjected to biweekly semen collections during 3 weeks. At each collection, sperm was pooled and divided into four aliquots and then diluted with Tris extender supplemented with 870, 87, or 8.7 µg/ml of R. officinalis essential oil, identified as treatments R, R5, and R10, respectively. Tris-based extender without any supplementation was considered as a control group. Diluted sperm was then stored at 4°C in the refrigerator and analyzed at 0, 6, 24, and 48 h using a computer-assisted sperm analyzer. Different semen parameters were measured including total motility, progressive motility, gametes velocities (straight line velocity [VSL], curvilinear velocity [VCL], and average path velocity [VAP]), amplitude of the lateral head displacement [ALH], and beat-cross frequency [BCF]. Results: The phytochemical analysis of R. officinalis essential oil revealed the presence of 25 active components including seven major molecules: Camphor (18.88%), camphene (5.17%), 1,8-cineole (7.85%), β-thujene (13.66%), α-thujene (4.87%), chrysanthenone (12.05%), and β-cubenene (7.97%). The results showed a beneficial effect of R. officinalis essential oil on sperm cells motility, particularly when using the lowest concentrations, 8.7 and 87 µg/ml. Progressive motility and gametes velocities (VCL, VSL, and VAP), materializing the quality of gametes motility, showed highly statistically significant values (p<0.01) in 8.7 and 87 µg/ml treatments, especially from 6 h of storage at 4°C. Conversely, the highest concentration (870 µg/ml) showed harmful effects with a total spermicidal activity after 24 h of storage. Conclusion: The current results revealed the positive impact of R. officinalis essential oil on rooster sperm at 4°C short-term storage probably through fighting against oxidative stress and cold shock damages.

Abnormally increased placental expression of major histocompatibility complex class I (MHC-I) molecules at the trophoblastic surface has been suggested previously to be the cause of early fetal loss in nuclear transfer (NT) bovine pregnancies. Here, we report the lack of expression of MHC-I at the trophoblastic surface at D30 and D60 and in placentomes from D60 to term in placentas obtained by NT from three different genotypes and by artificial insemination, whatever the outcome of the pregnancy. MHC-I expression was assessed by immunohistochemistry using four different antibodies, including a novel ␤2-microglobulin antibody. The MHC-I type of the clones was established using reference strand-mediated conformation analysis (RSCA); however, since it proved problematic to type the recipient animals in the same way, outcome of pregnancy could not be related to MHC compatibility. In conclusion, the present study provides no evidence to support abnormal expression of MHC-I on the trophoblastic surface in clones as a major cause of fetal loss during pregnancy after NT.

Studies of postpartum endometrial physiologic and immune mechanisms in cows are compromised by the difficulty in acquiring tissue of suitable quality and in sufficient quantity (Bos taurus). Endometrial biopsy sampling has attracted concern regarding potential animal ill-health and perturbed subsequent fertility. Here, we describe a method of endometrial biopsy that obtains highquality tissue samples and does not compromise fertility. Using a Hauptner instrument, endometrial biopsies were taken at 15, 30, and 60 d postpartum from 13 mixed-breed beef cows. The effects of repeat biopsy on health (heart rate, respiration rate, color of mucous membranes, rectal temperature), onset of estrous cyclicity, and first service conception rate were monitored. Extensive daily clinical examinations revealed no signs of ill-health. All cows had resumed estrous cyclicity at 60 d postpartum. A conception rate of 77% was achieved after estrus synchronization and artificial insemination. Each biopsy yielded intact endometrial tissue and nucleic acid suitable for extensive histologic and molecular analysis, respectively. We conclude that when carried out appropriately, bovine endometrial biopsy is a safe and reliable technique for assessing postpartum uterine function or health. #

The effect of exercise on mare reproductive efficiency was evaluated by comparing rates of embryo recovery from mares assigned to either an exercise regimen or a non-exercise (control) regimen. Exercised mares were worked daily for 30 min under average ambient conditions of >30 • C and >50% humidity. Mares were inseminated during estrus and subjected to uterine flush for embryo recovery on d 7 after ovulation for two consecutive cycles. After this, mares were allocated to the opposite group and allowed an estrous cycle without reproductive manipulation; then insemination and uterine flushing were conducted on two more consecutive cycles. Prostaglandin F 2␣ was administered on the day of uterine flush. Mare rectal temperature increased during exercise from a mean of 38 • C to a mean of 39.9 • C. Mares had ovulations from smaller follicles when exercised than they did under control conditions (39.8 ± 0.5 compared with 41.5 ± 0.5 mm diameter; P < 0.05), and had an increased time from PGF 2␣ administration to subsequent ovulation (8.47 ± 0.337 compared with 9.27 ± 0.294 d; P < 0.05). Embryo recovery from control mares was 22 of 35 (63%). Fewer embryos were recovered from exercised mares (11 of 32, 34%; P < 0.05). The proportion of embryos classified as Grade 1 tended to be less in exercised than in non-exercised mares (4 of 11, 36% compared with 16 of 22, 73%; P = 0.051). These data indicate that exercising mares in a hot and humid environment are associated with changes in ovarian follicle development and ovulation, and a reduction in embryo recovery.

As the law of parentage is striving to meet the challenges of new reproductive technologies, dealing with cross-border surrogacies emerges as one of the most pressing topics in international family law. The current legal situation as regards surrogacy is quite diverse – throughout the world but also within Europe. Legal diversity has recently made a lot of people engage in so-called “procreative tourism”: Coming from a country with a rather strict approach, they commission women in one of the more liberal countries to carry a child for them, and once the baby is born, they try to take it to their home country, thereby obviating the surrogacy ban that prevents them from entrusting a surrogate mother at home. European courts struggle with a coherent approach on how to treat those citizens who went abroad to have a baby. Meanwhile, legal research and the Hague Conference on Private International Law think about a convention in order to ease cross-border recognition of surrogacy.

Palabras clave: calidad seminal, inseminación artificial, ovinos, fertilidad, semen congelado RESUMEN Se analizó la relación entre la calidad del semen post-descongelamiento y la eficiencia reproductiva en ovinos Merino. Se utilizó semen congelado de 10 carneros en una majada de 645 ovejas adultas. Se sincronizaron los estros mediante esponjas vaginales con progestágenos y una dosis de 300 UI de eCG (gonadotrofina coriónica equina). A las 60±2 horas post tratamiento progestacional, se efectuó la inseminación artificial intrauterina por laparoscopía sistemática (IALS). Se evaluó la calidad seminal post-descongelamiento mediante las siguientes pruebas: movilidad masal microscópica (MMm), movilidad individual progresiva (MIP), porcentaje de espermatozoides vivos (PEV) y el test hiposmótico (Host). Se determinó el número total de espermatozoides (NTE). La correlación entre MMm y MIP evidenció una asociación significativa (P< 0.05). Las correlaciones entre MMm y PEV, y entre MMm y Host no fueron estadísticamente significativas (P> 0.05). El PEV se relacionó significativamente con la MIP y con el Host, los que a su vez presentaron una correlación significativa entre sí. Los análisis de regresión lineal simple determinaron que la variabilidad de la eficiencia reproductiva, expresada como el porcentaje de preñez por carnero, puede ser explicada significativamente por los valores de MIP y de PEV. La MMm y el Host no permitieron explicar la variabilidad de la fertilidad del semen. El análisis de regresión lineal múltiple, conjuntamente con el método de selección Stepwise, determinó que la MIP (R2 = 0.67, P = 0.0036) fue lo que mejor explicó la variabilidad observada en la eficiencia reproductiva obtenida en la IALS.

Artificial insemination (AI) is an important tool for genetic improvement in livestock. The success rate of AI is influenced by many factors, including the semen quality used for inseminating the female (1). Fresh semen is processed and stored in liquid nitrogen before being distributed to the farmers. The use of liquid nitrogen was to freeze the semen for long-term storage. Environmental factors such as elevated temperature and human errors can affect the semen quality during semen processing. Therefore, the semen processing handling is critical to maintain the sperm quality. Semen quality evaluation during processing is crucial to make sure the semen is in good condition before stored and distributed. To ensure even minimal success, proper diluent, sperm dilution rate, cooling rate and thawing rate are essentials to maximize the post-thaw recovery of sperm and consequently fertility .

Our expanding knowledge of the control of follicular wave dynamics during the bovine estrous cycle has resulted in renewed enthusiasm for the prospects of precisely controlling the follicular and luteal dynamics and finely controlling the time of ovulation. Follicular wave development can be controlled mechanically by ultrasound-guided follicle ablation or hormonally by treatments with GnRH or estradiol and progestogen/progesterone in combination. Treatment of cattle with GnRH in combination with prostaglandin Fla (PGF) 7 d later and a second GnRH 48 h after PGF (known as Ovsynch) has resulted in acceptable pregnancy rates after fixed-time AI in lactating dairy cows and in recipients in which embryos were transferred without estrus detection. Alternatively, treatments with estradiol and progestogen/progesteronereleasing devices resulted in synchronous emergence of a new follicular wave and, when a second estradiol treatment was given 24 h after device removal, synchronous ovulation and high pregnancy rates to fixed-time AI. Self-appointed embryo transfer (without estrus detection) using estradiol and progesterone treatments have resulted in pregnancy rates comparable with those obtained with recipients transferred 7 d after es&us. Furthermore, estradiol and progesterone treatments combined with PGF and eCG (given 1 d after the expected time of wave emergence) have resulted in high rates of recipients selected for transfer (84.6%) and an overall pregnancy rate of 48.7% (recipients pregnant/recipients treated). Estradiol and progestogen/progesterone treatments have also been widely used for self-appointed superstimulation protocols with equivalent embryo production to that of donor cows superstimulated using the traditional approach beginning 8 to 12 d after estrus. In summary, exogenous control of luteal and follicular development facilitates the application of assisted reproductive technologies in cattle by offering the possibility of planning the superstimulation of donors and synchronization of recipients at a self-appointed time, without the necessity of estrus detection and without sacrificing results.

and artificial insemination (AI) in the canine has become a common practice in veterinary medicine. Chilled dog semen is easy to handle, and several extenders can be used. The aim of this study was to compare the effects on canine spermatozoa of seminal plasma and 3 extenders commonly used for chilled semen preservation in clinical practice. The characteristics evaluated were sperm motility; velocity; plasma membrane status (assessed with a fluorescence staining technique and hypo-osmotic swelling test); acrosome morphology; semen pH; and semen osmolarity. These criteria were monitored daily in the ejaculates of 11 dogs. The ejaculates were divided into 4 aliquots. Each aliquot was extended in autologous seminal plasma, egg-yolk Tris, egg-yolk milk or egg-yolk cream and preserved at 4°C for 4 d. In 10 of 11 semen samples extended in autologous seminal plasma, motility had already decreased to 0% by Day 2, and the percentage of spermatozoa with intact membranes was lower than in the 3 extenders (P<O.OS). Motility up to Day 4 was higher in egg-yolk Tris-stored spermatozoa (53.6%) than in those preserved in egg-yolk milk (30.4%) and egg-yolk cream (14.1%). Spermatozoa stored in egg-yolk Tris also had the highest sperm velocity, whereas no difference was found in plasma membrane or acrosome status (P>O.O5). Egg-yolk Tris extender seems to be superior to the other extenders tested, to preserve dog semen at 4°C although differences were not significant for all the parameters.

This review presents an overview of the technical bases of in vivo and in vitro embryo production in sheep and goat. The current limitations of in vivo production, such as variability of response to the hormonal treatment, fertilization failure in females showing a high ovulatory response, and the importance of premature regressed CL in the goat, are described along with possibilities for improvement. The new prospects offered by in vitro embryo production, by repeated ovum pickup from live females and by juvenile breeding, are presented along with their limiting steps and research priorities. The recent improvements of embryo production and freezing technologies could be used for constitution of¯ocks without risks of disease transmission and will allow wider propagation of valuable genes in small ruminants populations in the future. #

The present work optimizes procedures for artificial insemination of European catfish, Silurus glanis L., with goals to increase collection of sperm and hatching rate. We address technical aspects of immobilizing solution (IS), activation solution (AS), process of insemination, activation of gametes and elimination of eggs stickiness with a practical solution for artificial propagation in hatcheries. Spermiation was stimulated and could be sustained over a period of 1 month after weekly carp pituitary (CP) injection of 5 mg kg À 1 b.w. Males produced significantly the largest quantity of sperm, 0.12 -0.13Á10 9 spermatozoa kg À 1 b.w., after third and fourth injections. The best IS for sperm was determined as solution containing 170 -200 mM NaCl, 30 mM Tris -HCl, pH 7 and activation solution for activation of gametes containing 17 mM NaCl, 5 mM Tris -HCl, pH 7. The ratio of 1:2 rather than ratio of 1:1 in the control batch (volume of activation solution in milliliters/grams of eggs) increased the hatchability up to 68%. The highest hatching success of 82 -88% from four individual females were found for sperm number of 800 -80,000 spermatozoa egg À 1 , in comparison to 26% hatching at 80 spermatozoa egg À 1 . The best time for application of alcalase enzyme for elimination of egg stickiness was 3 min after gamete activation at concentration of 20 ml enzyme l À 1 with exposure of 2 min. D

A critical analysis of posthumous conception African style (“PPAS”) and posthumous conception Western style (“PPWS”) reveals inconsistencies between the two practices and sheds light on similarities in practices across cultures and civilizations -- similarities that are seemingly ignored by international human rights bodies and human rights activists. Under PPAS, there are at least four ways in which a child can be conceived posthumously. A commonality among all four is that no genetic link exists between the dead man and any children attributable to him. PPAS has and continues to be used in many patrilineal African cultures in order to ensure societal stability. Over the years, Nigerian courts have concluded that the various customary practices relating to posthumous procreation are invalid and unenforceable under the repugnancy principle. However, a hasty application of international human rights law (“IHRL”) and the repugnancy test to PPAS could be problematic and ultimately counterproductive. PPAS creates many concerns with the children and women involved in the practice as well as overall public health. In contrast to PPAS, PPWS provides that the dead man is the genetic father of the any children attributable to him. PPWS is achieved through the cryopreservation of sperm and the subsequent artificial insemination of a woman. PPWS, like PPAS, also causes concerns related to children resulting from a posthumous conception. A comparative study of both ancient and modern practices of posthumous procreation shows many similarities between cultures and raises important questions about marriage, paternity, and mortality in both Africa and the West.