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Frontiers in Veterinary Science 2024South Africa is home to numerous indigenous and locally developed sheep (Nguni Pedi, Zulu, and Namaqua Afrikaner, Afrino, Africander, Bezuidenhout Africander, Damara,...
South Africa is home to numerous indigenous and locally developed sheep (Nguni Pedi, Zulu, and Namaqua Afrikaner, Afrino, Africander, Bezuidenhout Africander, Damara, Dorper, Döhne Merino, Meat Master, South African Merino, South African Mutton Merino, Van Rooy, and Dorper), goat (SA veld, Tankwa, Imbuzi, Bantu, Boer, and Savanna) and cattle (Afrigus, Afrikaner, Bolowana, Bonsmara, Bovelder, Drakensberger, South African Angus, South African Dairy Swiss, South African Friesland, South African Red, and Veld Master) animals. These breeds require less veterinary service, feed, management efforts, provide income to rural and or poor owners. However, most of them are under extinction risks and some with unknown status hence, require immediate conservation intervention. To allow faster genetic progress on the endangered animals, it is important to generate productive animals while reducing wastages and this can be achieved through sex-sorted semen. Therefore, this systematic review is aimed to evaluate the prospects of X and Y-sexed semen in ruminant livestock and some solutions that can be used to address poor sex-sorted semen and its fertility. This review was incorporated through gathering and assessing relevant articles and through the data from the DAD-IS database. The keywords that were used to search articles online were pre-gender selection, indigenous ecotypes, fertility, flow cytometry, artificial insemination, conservation, and improving sexed semen. Following a careful review of all articles, PRISMA guidelines were used to find the articles that are suitable to address the aim of this review. Sex-sorted semen is a recently introduced technology gaining more attention from researchers particularly, in the conservation programs. Preselection of semen based on the sex chromosomes (X- and or Y-bearing chromosomes) is of paramount importance to obtain desired sex of the offspring and avoid animal wastage as much as possible. However, diverse factors can affect quality of semen of different animal species especially after sex-sorting. Flow cytometry is a common method used to select male and female sperm cells and discard dead and abnormal sperm cells during the process. Thus, sperm sexing is a good advanced reproductive technology (ART) however, it is associated with the production of oxidative stress (OS) and DNA fragmentation (SDF). These findings, therefore, necessitates more innovation studies to come up with a sexing technology that will protect sperm cell injuries during sorting in frozen-thawed.
PubMed: 38655533
DOI: 10.3389/fvets.2024.1384768 -
The Cochrane Database of Systematic... Oct 2005The postcoital test has poor diagnostic and prognostic characteristics. Nevertheless, some physicians believe it can identify scanty or abnormal mucus that might impair... (Review)
Review
BACKGROUND
The postcoital test has poor diagnostic and prognostic characteristics. Nevertheless, some physicians believe it can identify scanty or abnormal mucus that might impair fertility. One way to avoid 'hostile' cervical mucus is intrauterine insemination. With this technique, the physician injects sperm directly into the uterine cavity through a small catheter passed through the cervix; the theory is to bypass the "hostile" cervical mucus. Although most gynaecological societies do not endorse use of intrauterine insemination for hostile cervical mucus, some physicians consider it an effective treatment for women with infertility thought due to cervical mucus problems.
OBJECTIVES
The aim of this review was to determine the effectiveness of intrauterine insemination with or without ovarian stimulation in women with cervical hostility who failed to conceive.
SEARCH STRATEGY
We searched Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library Issue 2, 2005, MEDLINE (1966 to June 2005), EMBASE (1980 to June 2005), POPLINE (to June 2005) and LILACS (to June 2005). In addition, we contacted experts and searched the reference list of relevant articles and book chapters.
SELECTION CRITERIA
We included randomized and quasi-randomized controlled trials comparing intrauterine insemination with intercourse timed at the presumed fertile period. Participants were women with cervical hostility who failed to conceive for at least one year.
DATA COLLECTION AND ANALYSIS
We assessed the titles and abstracts of 386 publications and two reviewers independently abstracted data on methods and results from five studies identified for inclusion. The main outcome is pregnancy rate per couple.
MAIN RESULTS
We did not pool the outcomes of the included five studies in a meta-analysis due to the methodological quality of the trials and variations in the patient characteristics and interventions. Narrative summaries of the outcomes are provided. Each study was too small for a clinically relevant conclusion. None of the studies provided information on important outcomes such as spontaneous abortion, multiple pregnancies, and ovarian hyperstimulation syndrome.
AUTHORS' CONCLUSIONS
There is no evidence from the published studies that intrauterine insemination is an effective treatment for cervical hostility. Given the poor diagnostic and prognostic properties of the postcoital test and the observation that the test has no benefit on pregnancy rates, intrauterine insemination (with or without ovarian stimulation) is unlikely to be a useful treatment for putative problems identified by postcoital testing.
Topics: Biomarkers; Cervix Mucus; Coitus; Female; Humans; Infertility; Insemination, Artificial, Homologous; Luteinizing Hormone; Time Factors
PubMed: 16235303
DOI: 10.1002/14651858.CD002809.pub2 -
Human Reproduction Update Jan 2021Registry data from the Human Fertilisation and Embryology Authority (HFEA) show an increase of 40% in IUI and 377% in IVF cases using donor sperm between 2006 and 2016. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Registry data from the Human Fertilisation and Embryology Authority (HFEA) show an increase of 40% in IUI and 377% in IVF cases using donor sperm between 2006 and 2016.
OBJECTIVE AND RATIONALE
The objective of this study was to establish whether pregnancies conceived using donor sperm are at higher risk of obstetric and perinatal complications than those conceived with partner sperm. As more treatments are being carried out using donor sperm, attention is being given to obstetric and perinatal outcomes, as events in utero and at delivery have implications for long-term health. There is a need to know if there is any difference in the outcomes of pregnancies between those conceived using donor versus partner sperm in order to adequately inform and counsel couples.
SEARCH METHODS
We performed a systematic review and meta-analysis of the outcomes of pregnancies conceived using donor sperm compared with partner sperm. Searches were performed in the OVID MEDLINE, OVID Embase, CENTRAL and CINAHL databases, including all studies published before 11 February 2019. The search strategy involved search terms for pregnancy, infant, donor sperm, heterologous artificial insemination, donor gametes, pregnancy outcomes and perinatal outcomes. Studies were included if they assessed pregnancies conceived by any method using, or infants born from, donor sperm compared with partner sperm and described early pregnancy, obstetric or perinatal outcomes. The Downs and Black tool was used for quality and bias assessment of studies.
OUTCOMES
Of 3391 studies identified from the search, 37 studies were included in the review and 36 were included in the meta-analysis. For pregnancies conceived with donor sperm, versus partner sperm, there was an increase in the relative risk (RR) (95% CI) of combined hypertensive disorders of pregnancy: 1.44 (1.17-1.78), pre-eclampsia: 1.49 (1.05-2.09) and small for gestational age (SGA): 1.42 (1.17-1.79) but a reduced risk of ectopic pregnancy: 0.69 (0.48-0.98). There was no difference in the overall RR (95% CI) of miscarriage: 0.94 (0.80-1.11), gestational diabetes: 1.49 (0.62-3.59), pregnancy-induced hypertension (PIH): 1.24 (0.87-1.76), placental abruption: 0.65 (0.04-10.37), placenta praevia: 1.19 (0.64-2.21), preterm birth: 0.98 (0.88-1.08), low birth weight: 0.97 (0.82-1.15), high birthweight: 1.28 (0.94-1.73): large for gestational age (LGA): 1.01 (0.84-1.22), stillbirth: 1.23 (0.97-1.57), neonatal death: 0.79 (0.36-1.73) and congenital anomaly: 1.15 (0.86-1.53).
WIDER IMPLICATIONS
The majority of our findings are reassuring, except for the mild increased risk of hypertensive disorders of pregnancy and SGA in pregnancies resulting from donor sperm. However, the evidence for this is limited and should be interpreted with caution because the evidence was based on observational studies which varied in their quality and risk of bias. Further high-quality population-based studies reporting obstetric outcomes in detail are required to confirm these findings.
Topics: Female; Fertilization in Vitro; Humans; Infant, Newborn; Male; Placenta; Pregnancy; Pregnancy Outcome; Premature Birth; Spermatozoa
PubMed: 33057599
DOI: 10.1093/humupd/dmaa030 -
The Cochrane Database of Systematic... Dec 2014In many countries intrauterine insemination (IUI) is the treatment of first choice for a subfertile couple when the infertility work up reveals an ovulatory cycle, at... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
In many countries intrauterine insemination (IUI) is the treatment of first choice for a subfertile couple when the infertility work up reveals an ovulatory cycle, at least one open Fallopian tube and sufficient spermatozoa. The final goal of this treatment is to achieve a pregnancy and deliver a healthy (singleton) live birth. The probability of conceiving with IUI depends on various factors including age of the couple, type of subfertility, ovarian stimulation and the timing of insemination. IUI should logically be performed around the moment of ovulation. Since spermatozoa and oocytes have only limited survival time correct timing of the insemination is essential. As it is not known which technique of timing for IUI results in the best treatment outcome, we compared different techniques for timing IUI and different time intervals.
OBJECTIVES
To evaluate the effectiveness of different synchronisation methods in natural and stimulated cycles for IUI in subfertile couples.
SEARCH METHODS
We searched for all publications which described randomised controlled trials of the timing of IUI. We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (1966 to October 2014), EMBASE (1974 to October 2014), MEDLINE (1966 to October 2014) and PsycINFO (inception to October 2014) electronic databases and prospective trial registers. Furthermore, we checked the reference lists of all obtained studies and performed a handsearch of conference abstracts.
SELECTION CRITERIA
Randomised controlled trials (RCTs) comparing different timing methods for IUI were included. The following interventions were evaluated: detection of luteinising hormone (LH) in urine or blood, single test; human chorionic gonadotropin (hCG) administration; combination of LH detection and hCG administration; basal body temperature chart; ultrasound detection of ovulation; gonadotropin-releasing hormone (GnRH) agonist administration; or other timing methods.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected the trials, extracted the data and assessed study risk of bias. We performed statistical analyses in accordance with the guidelines for statistical analysis developed by The Cochrane Collaboration. The overall quality of the evidence was assessed using GRADE methods.
MAIN RESULTS
Eighteen RCTs were included in the review, of which 14 were included in the meta-analyses (in total 2279 couples). The evidence was current to October 2013. The quality of the evidence was low or very low for most comparisons . The main limitations in the evidence were failure to describe study methods, serious imprecision and attrition bias.Ten RCTs compared different methods of timing for IUI. We found no evidence of a difference in live birth rates between hCG injection versus LH surge (odds ratio (OR) 1.0, 95% confidence interval (CI) 0.06 to 18, 1 RCT, 24 women, very low quality evidence), urinary hCG versus recombinant hCG (OR 1.17, 95% CI 0.68 to 2.03, 1 RCT, 284 women, low quality evidence) or hCG versus GnRH agonist (OR 1.04, 95% CI 0.42 to 2.6, 3 RCTS, 104 women, I(2) = 0%, low quality evidence).Two RCTs compared the optimum time interval from hCG injection to IUI, comparing different time frames that ranged from 24 hours to 48 hours. Only one of these studies reported live birth rates, and found no difference between the groups (OR 0.52, 95% CI 0.27 to 1.00, 1 RCT, 204 couples). One study compared early versus late hCG administration and one study compared different dosages of hCG, but neither reported the primary outcome of live birth.We found no evidence of a difference between any of the groups in rates of pregnancy or adverse events (multiple pregnancy, miscarriage, ovarian hyperstimulation syndrome (OHSS)). However, most of these data were very low quality.
AUTHORS' CONCLUSIONS
There is insufficient evidence to determine whether there is any difference in safety and effectiveness between different methods of synchronization of ovulation and insemination. More research is needed.
Topics: Adult; Body Temperature; Chorionic Gonadotropin; Female; Gonadotropin-Releasing Hormone; Humans; Infertility; Insemination, Artificial; Luteinizing Hormone; Male; Ovulation Detection; Randomized Controlled Trials as Topic; Time Factors; Young Adult
PubMed: 25528596
DOI: 10.1002/14651858.CD006942.pub3 -
The Cochrane Database of Systematic... Apr 2010Intrauterine insemination (IUI) should logically be performed around the moment of ovulation. Since spermatozoa and oocytes have only limited survival times correct... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Intrauterine insemination (IUI) should logically be performed around the moment of ovulation. Since spermatozoa and oocytes have only limited survival times correct timing is essential. As it is not known which technique of timing for IUI results in the best treatment outcome, we compared different techniques for timing IUI and different time intervals.
OBJECTIVES
To evaluate the effectiveness of different synchronisation methods in natural and stimulated cycles for IUI in subfertile couples.
SEARCH STRATEGY
We searched for all publications which described randomised controlled trials of the timing of IUI. We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), (1966 to March 2009), EMBASE (1974 to March 2009) and Science Direct (1966 to March 2009) electronic databases. Furthermore, we checked the reference lists of all obtained studies and performed a handsearch of conference abstracts.
SELECTION CRITERIA
Only truly randomised controlled trials comparing different timing methods for IUI were included. The following interventions were evaluated: detection of luteinising hormone (LH) in urine or blood, single test; human chorionic gonadotropin (hCG) administration; combination of LH detection and hCG administration; basal body temperature chart; ultrasound detection of ovulation; gonadotropin-releasing hormone (GnRH) agonist administration; or other timing methods.
DATA COLLECTION AND ANALYSIS
Two review authors independently selected the trials to be included according to the above mentioned criteria. We performed statistical analyses in accordance with the guidelines for statistical analysis developed by The Cochrane Collaboration.
MAIN RESULTS
Ten studies were included comparing urinary LH surge versus hCG injection; recombinant hCG versus urinary hCG; and hCG versus a GnRH agonist. One study compared the optimum time interval from hCG injection to IUI. The results of these studies showed no significant differences between different timing methods for IUI expressed as live birth rates: hCG versus LH surge (odds ratio (OR) 1.0, 95% CI 0.06 to 18); urinary hCG versus recombinant hCG (OR 1.2, 95% CI 0.68 to 2.0); and hCG versus GnRH agonist (OR 1.1, 95% CI 0.42 to 3.1). All the secondary outcomes analysed showed no significant differences between treatment groups.
AUTHORS' CONCLUSIONS
There is no evidence to advise one particular treatment option over another. The choice should be based on hospital facilities, convenience for the patient, medical staff, costs and drop-out levels. Since different time intervals between hCG and IUI did not result in different pregnancy rates, a more flexible approach might be allowed.
Topics: Adult; Body Temperature; Chorionic Gonadotropin; Female; Gonadotropin-Releasing Hormone; Humans; Infertility; Insemination, Artificial; Luteinizing Hormone; Male; Ovulation Detection; Randomized Controlled Trials as Topic; Time Factors; Young Adult
PubMed: 20393953
DOI: 10.1002/14651858.CD006942.pub2 -
The Cochrane Database of Systematic... 2000Artificial insemination with sperm is used to improve the chances of conception for various causes of infertility. Traditionally, sperm is deposited in or around the... (Review)
Review
BACKGROUND
Artificial insemination with sperm is used to improve the chances of conception for various causes of infertility. Traditionally, sperm is deposited in or around the endocervical canal (cervical insemination - CI). Some studies reported higher pregnancy rates if sperm was deposited in the uterine cavity itself (intrauterine insemination - IUI), but most were uncontrolled. However the cost and the risks (infection and anaphylaxis) of IUI may also be higher.
OBJECTIVES
The objective of this review was to assess the effects of depositing donor sperm in the uterine cavity (intrauterine insemination) compared to cervical insemination.
SEARCH STRATEGY
The Cochrane Subfertility Review Group specialised register of controlled trials was searched.
SELECTION CRITERIA
Randomised trials comparing intrauterine insemination and cervical insemination, using fresh or cryopreserved semen, with or without ovarian hyperstimulation.
DATA COLLECTION AND ANALYSIS
Trial quality assessment and data extraction were done independently by two reviewers.
MAIN RESULTS
Twelve studies were included. They comprised 697 patients undergoing 2215 treatment cycles. Ten trials used frozen semen, with three using ovarian hyperstimulation. Overall the methodological quality of the trials was low. The overall pregnancy rate per cycle in the intrauterine insemination group was 18% compared to 5% for cervical insemination. When cryopreserved donor sperm was used, the overall chance of pregnancy in spontaneous or clomiphene-corrected cycles was significantly higher with intrauterine insemination. This was irrespective of whether pregnancy rates were calculated on a per cycle (odds ratio 2. 63, 95% confidence interval 1.85 to 3.73) or per patient (odds ratio 3.86, 95% confidence interval 1.81 to 8.25) basis. The greatest benefit appeared in trials with poor pregnancy rates (less than 6%) for cervical insemination. There was no difference in pregnancy rate between intrauterine and cervical insemination when fresh donor sperm was used (odds ratio 0.90, 95% confidence interval 0.36 to 2. 24).
REVIEWER'S CONCLUSIONS
Intrauterine insemination appears to be beneficial when cervical insemination using cryopreserved donor sperm has had low pregnancy rates. This applies to spontaneous, clomiphene corrected and gonadotrophin stimulated cycles. However it may offer little benefit where high pregnancy rates have been achieved with cervical insemination. There appears to be no additional benefit from intrauterine insemination when fresh sperm is used for donor insemination.
Topics: Cervix Uteri; Female; Humans; Insemination, Artificial; Pregnancy; Pregnancy Rate; Uterus
PubMed: 10796709
DOI: 10.1002/14651858.CD000317 -
PloS One 2014Recent studies have indicated the use of gonadotropin-releasing hormone antagonists (GnRH-ant) as an adjuvant treatment to prevent premature luteinization (PL) and... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Recent studies have indicated the use of gonadotropin-releasing hormone antagonists (GnRH-ant) as an adjuvant treatment to prevent premature luteinization (PL) and improve the clinical outcomes in patients undergoing controlled ovarian stimulation (COS) with intrauterine insemination (IUI). However, the results of these studies are conflicting.
METHODS
We conducted a systematic review and meta-analysis of randomized trials aiming to compare the clinical efficacy of GnRH-ant in COS/IUI cycles. Twelve studies were identified that met inclusion criteria and comprised 2,577 cycles assigned to COS/IUI combined GnRH-ant or COS/IUI alone.
RESULTS
Meta-analysis results suggested that GnRH-ant can significantly increase the clinical pregnancy rate (CPR) (OR = 1.42; 95% CI, 1.13-1.78) and decrease the PL rate (OR = 0.22, 95% CI, 0.16-0.30) in COS/IUI cycles. Subgroup analysis results suggested statistically significant improvement in the CPR in non-PCOS patients (OR = 1.54; 95% CI, 1.03-2.31) but not in the PCOS population (OR = 1.65; 95% CI, 0.93-2.94) and multiple mature follicle cycles (OR = 1.87; 95% CI, 0.27-12.66). There were no difference in the miscarriage and multiple pregnancy rates between the groups.
CONCLUSION
This meta-analysis suggested that GnRH-ant can reduce the incidence of PL and increase the CPR when used in COS/IUI cycles, and it was especially useful for non-PCOS patients. However, evidence to support its use in PCOS patients is still insufficient.
Topics: Adolescent; Adult; Female; Fertilization in Vitro; Gonadotropin-Releasing Hormone; Gonadotropins; Hormone Antagonists; Humans; Infertility; Insemination, Artificial; Luteinization; Male; Ovulation Induction; Pregnancy; Pregnancy Rate; Young Adult
PubMed: 25299186
DOI: 10.1371/journal.pone.0109133 -
Revista de Salud Publica (Bogota,... 2014To determine the factors associated with the presence of cytoplasmic droplets in boars. (Review)
Review
OBJECTIVE
To determine the factors associated with the presence of cytoplasmic droplets in boars.
METHODS
A systematic review was carried out in which 133 articles were found, 70 were eliminated due to duplication, and 65 were finally selected: 57 in Cab Abstract, 39 in Pub Med, 20 in Agricola, and 17 in Science Direct. Forty-seven articles were found with an available full text. Data was tabulated in EpiData Entry and transferred to the Stata version 12.0 program.
RESULTS
Factors Associated with cytoplasmic droplets are: Climatic and environmental variables; ejaculation frequency with intervals of less than three weeks; spermatic morphologic alterations in tail (coiled and distal reflex); DNA fragmentation; and enzymatic factors related to seminal biochemistry. Work carried out in equatorial climate regions or that focused on the analysis of the implications of CDs in artificial insemination centers was not found.
CONCLUSIONS
The information is characterized by a wide heterogeneity and diversity studies. A contribution was made to Veterinary Public Health in Colombia on the importance of CGs as factors that limit reproductive processes in swine. It was not possible to determine the temporal relationship between the cause and effect of CDs.
Topics: Animals; Climate; DNA Fragmentation; Ejaculation; Inclusion Bodies; Insemination, Artificial; Male; Semen Analysis; Spermatozoa; Sus scrofa
PubMed: 26120862
DOI: No ID Found -
The Cochrane Database of Systematic... 2004Semen preparation techniques for assisted reproduction, including intrauterine insemination (IUI), were developed to separate the motile morphological normal... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Semen preparation techniques for assisted reproduction, including intrauterine insemination (IUI), were developed to separate the motile morphological normal spermatozoa. Leucocytes, bacteria and dead spermatozoa produce oxygen radicals that negatively influence the ability to fertilize the egg. The yield of as many motile, morphologically normal spermatozoa might influence treatment choices and therefore outcomes.
OBJECTIVES
To compare the effectiveness of gradient, swim-up, or wash and centrifugation in subfertile couples undergoing intrauterine insemination (IUI) on clinical outcome as well as on semen parameters.
SEARCH STRATEGY
We searched the Menstrual Disorders and Subfertility Group's trials register (30 June 2003), MEDLINE (1966 to July 2003), EMBASE (1980 to July 2003), Science Direct Database (1966 to July 2003), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 3, 2003), National Research Register (2000 to Issue 2, 2003), Biological Abstracts (2000 to June 2003), CINAHL (1982 to July 2003) and reference lists of relevant articles. We also contacted experts and authors in the field.
SELECTION CRITERIA
Parallel randomised controlled trials (RCTs), comparing the efficacy of semen preparation techniques used for subfertile couples undergoing IUI, were included. RCTs or split sample studies examining semen parameters after different semen preparation techniques were also included.
DATA COLLECTION AND ANALYSIS
Two reviewers independently assessed trial quality and extracted data. Study authors were contacted for additional information.
MAIN RESULTS
Two randomised controlled trials comparing clinical outcomes, including 81 participants in total, were included in the meta-analysis (Dodson 1998-I/ II; Xu 2000-I/ II). Both studies compared swim-up technique versus gradient technique in 65 subfertile couples undergoing IUI. One study compared the effectiveness of both techniques with wash technique. No trials reported the primary outcome of live birth. There was no statistically significant difference between pregnancy rates (PR) for swim-up versus gradient / wash centrifuge (Peto OR 0.55, 95% CI 0.17 to 1.76; Peto OR 1.74, 95% CI 0.2 to 14.9; PR/ couple swim-up 20%, gradient 40%, wash 12.5%) or gradient versus wash centrifuge (Peto OR 4.01, 95% CI 0.82 to 19.56; PR/ couple swim-up 15%, gradient 20%). There was no significant difference in the miscarriage rate (MR) per couple between either of the three treatment groups in the one trial reporting this outcome (MR/ couple swim-up 0%, gradient 10.3%, wash 0%. MR/ pregnancy gradient 30.3%). There was no statistically significant difference in the multiple pregnancy rate (MPR) per couple between either of the three treatment groups in Dodson 1998-I/ II (MPR/ couple swim -up 0%, gradient 0%, wash 6.3%). One triplet pregnancy was recorded. Fifteen studies comparing semen parameters after processing were included. Two studies were included in the meta-analysis, we were not able to pool results.
REVIEWERS' CONCLUSIONS
There is insufficient evidence to recommend any specific preparation technique. Large high quality randomised controlled trials, comparing the effectiveness of a gradient and/ or a swim-up and/ or wash and centrifugation technique on clinical outcome are lacking. Further randomised trials are warranted. Results from studies comparing semen parameters may suggest a preference for gradient technique, but firm conclusions cannot be drawn and the limitations should be taken into consideration.
Topics: Centrifugation, Density Gradient; Humans; Insemination, Artificial; Male; Randomized Controlled Trials as Topic; Semen; Specimen Handling; Sperm Count; Sperm Motility; Spermatozoa
PubMed: 15266536
DOI: 10.1002/14651858.CD004507.pub2 -
Journal of Dairy Science Oct 2017The objective of this study was to conduct a systematic review to identify and assess evidence and knowledge gaps in published observational studies that have... (Review)
Review
The objective of this study was to conduct a systematic review to identify and assess evidence and knowledge gaps in published observational studies that have investigated the relationship between mastitis and pregnancy loss (PL) in dairy cows. PubMed and ScienceDirect were used to search pertinent peer-reviewed research reports of interest. Screening of research reports was conducted at 3 levels: titles, abstracts, and full-text articles. The search identified 651 records for initial screening. The final screening process identified 8 qualified articles for review after removing 10 duplicate records, 582 titles, 31 abstracts, and 20 full-text articles. Two studies produced strong epidemiologic evidence indicating that (1) exposure to clinical mastitis during early gestation (first 45 d of gestation) is associated with subsequent PL during the following 90 d; and (2) subclinical mastitis 1 to 30 d before artificial insemination (AI) is associated with subsequent PL at 35 to 41 d of gestation. An additional study showed that exposure to clinical mastitis during early lactation in combination with low body condition can increase the risk of PL in dairy cows; however, the interaction effect between clinical mastitis and low body condition on PL was considered weak. Four other studies produced inconclusive evidence indicating that mastitis is a predisposing factor for PL in dairy cows, as the exposure risk period for mastitis overlapped with the follow-up period for diagnosis of PL in dairy cows. Finally, one study failed to identify a relationship between mastitis and PL in dairy cows. Further research is needed to (1) support the hypothesis that mastitis in combination with low body condition score (or other exposure factors) can increase the risk of PL, (2) compare the effect of clinical versus subclinical mastitis on PL, (3) compare the effect of mastitis before breeding and during gestation on PL, and (4) compare the effect of mastitis on PL in dairy cows during different lactations.
Topics: Abortion, Veterinary; Animals; Cattle; Female; Insemination, Artificial; Lactation; Mastitis, Bovine; Observational Studies as Topic; Pregnancy
PubMed: 28780088
DOI: 10.3168/jds.2017-12711