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Animal : An International Journal of... Feb 2021Numerous meat sheep breeding programs in developed and developing countries are characterized by incomplete sire information and a predominant use of natural matings....
Numerous meat sheep breeding programs in developed and developing countries are characterized by incomplete sire information and a predominant use of natural matings. These two parameters potentially affect the benefit of genomic selection (GS), especially for the selection of a late-in-life trait. Using stochastic simulations, the genetic gains obtained using genomic and conventional strategies for a maternal trait were evaluated in meat sheep population. Natural mating and artificial insemination (AI)-based designs, inspired by the current diversity of designs used for French meat sheep breeds, were modeled and three genomic strategies were tested and compared with a conventional selection strategy: parentage assignment, GS based on a male or a male and female reference population. Genomic selection based on a male reference population did not always outperform conventional selection. Its benefit depended on the design, the level of missing information on dam sires, and the level of AI. Genomic selection based on a male and female reference population always outperformed the conventional selection strategy, even if only 25 % of the females in the nucleus were genotyped.
Topics: Animals; Female; Genome; Genomics; Insemination, Artificial; Male; Meat; Selection, Genetic; Sheep
PubMed: 33573971
DOI: 10.1016/j.animal.2020.100040 -
The Canadian Veterinary Journal = La... Aug 2014This is a review of the physiology and endocrinology of the estrous cycle and how ovarian physiology can be manipulated and controlled for timed artificial insemination... (Review)
Review
This is a review of the physiology and endocrinology of the estrous cycle and how ovarian physiology can be manipulated and controlled for timed artificial insemination (TAI) in beef and dairy cattle. Estrus detection is required for artificial insemination (AI), but it is done poorly in dairy cattle and it is difficult in beef cattle. Protocols that synchronize follicle growth, corpus luteum regression and ovulation, allowing for TAI, result in improved reproductive performance, because all animals are inseminated whether they show estrus or not. As result, TAI programs have become an integral part of reproductive management in many dairy herds and offer beef producers the opportunity to incorporate AI into their herds. Gonadotropin-releasing hormone-based protocols are commonly used in North America for estrus synchronization as part of a TAI program. Protocols that increase pregnancy rates in lactating dairy cows and suckling beef cows have been developed. Protocols that improve pregnancy rates in heifers, acyclic beef cows, and resynchronized lactating dairy cows are also discussed.
Topics: Animal Husbandry; Animals; Cattle; Dairying; Estrus Detection; Estrus Synchronization; Female; Gonadotropin-Releasing Hormone; Insemination, Artificial; Meat; Pregnancy
PubMed: 25082993
DOI: No ID Found -
Journal of the American Association For... Mar 2021Intrauterine sperm injection for artificial insemination is difficult in cynomolgus macaques () and rhesus macaques () due to the complex structure of the cervical...
Intrauterine sperm injection for artificial insemination is difficult in cynomolgus macaques () and rhesus macaques () due to the complex structure of the cervical canal, which differs from that of humans. Despite the availability of several artificial insemination methods for macaques, pregnancy rates are inconsistent, and details regarding ovulation are unclear, thus warranting more effective methods. Therefore, we developed an effective, ultrasound-guided, transabdominal intrauterine artificial insemination method for cynomolgus macaques that involves timing sperm injection to coincide with the periovulation phase estimated according to rapid hormone measurement. We performed our intrauterine artificial insemination on 6 female macaques; 4 of the 5 animals that were predicted to have ovulated soon after insemination became pregnant, whereas the 1 macaque that was predicted not to have ovulated did not. Furthermore, we saw no evidence of injury, such as a conspicuous needle hole or bleeding on the surface of or inside the uterus, nor did our method result in any abnormalities in the mothers or their offspring. Thus, our ultrasound-guided, transabdominal, intrauterine artificial insemination method is rapid, safe, and effective in cynomolgus macaques.
Topics: Animals; Cervix Uteri; Female; Insemination, Artificial; Macaca fascicularis; Male; Ovulation; Pregnancy; Spermatozoa; Ultrasonography, Interventional
PubMed: 33568255
DOI: 10.30802/AALAS-JAALAS-20-000038 -
The Journal of Reproduction and... Feb 2024This study investigated the effects of timed artificial insemination (TAI) and equine chorionic gonadotropin (eCG) administration on lactating dairy cows under...
This study investigated the effects of timed artificial insemination (TAI) and equine chorionic gonadotropin (eCG) administration on lactating dairy cows under heat-stress conditions (average temperature-humidity index: 80). Timed artificial insemination was performed on the cows with (n = 57) or without (control, n = 41) supplementation with 500 IU of eCG at the day of PGF treatment using the CIDR-Ovsynch protocol. GnRH was administered, and a progesterone device (CIDR) was inserted on Day -10 of the treatment protocol. The CIDR was removed on Day -3, and the cows were treated with PGF. Two days later, a 2 GnRH injection was administered. Subsequently, AI was performed on Day 0 (16-20 h after the 2 GnRH injection), and pregnancy was diagnosed on Days 32 and 60. Plasma progesterone (P) concentrations were measured after AI. Results showed that the eCG group had a higher pregnancy per AI (P/AI) than the control group (43.9 vs. 12.2%, P = 0.002), which was also accompanied by elevated P levels. Four cows in the eCG group had multiple calves, representing 7.0 and 16.0% of the group and pregnant cows, respectively. In conclusion, 500 IU of eCG combined with CIDR-Ovsynch in lactating dairy cows under severe heat stress conditions successfully improved fertility. However, the protocol may have a slight risk of multiple births.
Topics: Pregnancy; Female; Cattle; Animals; Horses; Progesterone; Lactation; Dinoprost; Gonadotropin-Releasing Hormone; Estrus Synchronization; Insemination, Artificial; Chorionic Gonadotropin
PubMed: 38171736
DOI: 10.1262/jrd.2023-069 -
Animal : An International Journal of... May 2023The development of an ovulatory follicle is a fundamental premise for any reproductive management program that aims to optimize fertility in cattle. Controlling... (Review)
Review
The development of an ovulatory follicle is a fundamental premise for any reproductive management program that aims to optimize fertility in cattle. Controlling follicular development comprises the synchronized emergence of a new follicular wave, selection and growth of the dominant follicle, and synchronized ovulation of a high-quality oocyte. All these follicular events, primarily driven by gonadotropin secretion, occur under a very dynamic hormonal environment. In this sense, controlling follicular development demands essentially a precise manipulation of the hormonal environment to modulate gonadotropin secretion. Furthermore, the effectiveness of hormonal manipulation strategies in the management of follicular development depends on specific particularities of each situation, which can vary widely according to genetic groups (Bos taurus vs Bos indicus), nutritional, metabolic, and reproductive status. In this regard, the constant search for the refined synchrony between the hormonal treatments and reproductive events, considering these distinctions and particularities, have provided valuable information that contributed to the development of efficient reproductive programs. This manuscript discusses the physiological bases behind the development of fine-tuned timed-artificial insemination protocols for beef and dairy cattle that resulted in great improvements in reproductive efficiency of beef and dairy herds.
Topics: Female; Cattle; Animals; Estrus Synchronization; Reproduction; Fertility; Insemination, Artificial; Gonadotropins; Progesterone
PubMed: 37567674
DOI: 10.1016/j.animal.2023.100769 -
Journal of Assisted Reproduction and... Jul 2022The objective of this review is to define live birth rate (LBR) and clinical pregnancy rate (CPR) for women ≥ 40 undergoing ovulation induction (OI)/intrauterine... (Review)
Review
PURPOSE
The objective of this review is to define live birth rate (LBR) and clinical pregnancy rate (CPR) for women ≥ 40 undergoing ovulation induction (OI)/intrauterine insemination (IUI).
METHODS
A systematic review was performed in accordance with PRISMA guidelines using PubMed and Google Scholar. The primary and secondary outcomes of interest were LBR and CPR, respectively.
RESULTS
There were 636 studies screened of which 42 were included. In 8 studies which provided LBR for partner sperm, LBR/cycle ranged from 0 to 8.5% with majority being ≤ 4%. Cumulative LBR was 3.6 to 7.1% over 6 cycles with the majority of pregnancies in the first 4. In the four studies providing LBR for donor sperm cycles, LBR/cycle ranged from 3 to 7% with cumulative LBR of 12 to 24% over 6 cycles. The majority of pregnancies occurred in the first 6 cycles. There were three studies with LBR or CPR/cycle ≥ 1% for women ≥ 43. No studies provided data above this range for women ≥ 45. In 4 studies which compared OI/IUI and IVF, the LBR from IVF was 9.2 to 22% per cycle. In 7 studies which compared outcomes by stimulation protocol, no significant differences were seen.
CONCLUSION
For women ≥ 40 using homologous sperm, the highest probability of live birth is via IVF. However, if IVF is not an option, OI/IUI may be considered for up to 4 cycles in those using partner sperm or 6 cycles with donor sperm. For women > 45, OI/IUI is likely futile but a limited trial may be considered for psychological benefit while encouraging consideration of donor oocyte IVF or adoption. Use of gonadotropins does not appear to be more effective than oral agents in this age group.
Topics: Female; Fertilization in Vitro; Humans; Insemination; Insemination, Artificial; Male; Ovulation Induction; Pregnancy; Pregnancy Rate; Retrospective Studies; Semen
PubMed: 35731321
DOI: 10.1007/s10815-022-02551-8 -
Journal of Dairy Science Dec 2016The objective of this study was to determine the relative importance and contribution of several physiological factors as predictors of pregnancy risk in an Ovsynch...
The objective of this study was to determine the relative importance and contribution of several physiological factors as predictors of pregnancy risk in an Ovsynch (GnRH-1 - 7d - PGF - 56h - GnRH-2 - 16h - artificial insemination) timed artificial insemination program: (1) age of the corpus luteum (CL; original CL, new CL, or both in response to GnRH-1) and resulting progesterone concentrations as they affected luteolysis, ovulation after GnRH-2, and pregnancy risk; (2) progesterone concentration before GnRH-1 and GnRH-2 on subsequent ovulatory response to GnRH-1 and GnRH-2 as well as pregnancy risk; and (3) a combination of these factors in a multivariable logistic regression model to predict pregnancy risk. Original data from 7 published studies were combined including ovulatory responses to both GnRH injections, blood progesterone concentrations before GnRH-1, before PGF, and at 48h after PGF, pregnancy per artificial insemination at d 32 and 60 after artificial insemination, and intervening pregnancy loss. Ovulation outcomes were greater at lesser progesterone concentrations after both GnRH injections despite the fact that pregnancy outcomes were greatest when progesterone exceeded 3ng/mL before GnRH-1 and PGF, suggesting that greater progesterone concentration before GnRH-1 and incidence of ovulation act via different mechanisms to improve subsequent fertility. Ovulation after GnRH-2 and subsequent pregnancy outcome were positively related to lesser concentrations of progesterone at 48h after PGF; however, for maximal pregnancy outcome, progesterone should be <0.5ng/mL. Cows with a CL that also formed a new CL after GnRH-1 had the greatest pregnancy outcome, whereas cows with only a new CL (i.e., anovulatory cows and those at or near estrus without a CL at GnRH-1) had the poorest pregnancy outcome. Pregnancy loss was not affected by CL status during the timed artificial insemination program. Receiver operator curves produced cut points of progesterone concentration that predicted ovulation and pregnancy risk. Selected cut points of progesterone concentration 48h after PGF produced true positive risks greater than 90% and false positive risks less than 25%, thus demonstrating the high predictability of ovulation after GnRH-2 and subsequent pregnancy outcome based on progesterone concentration. We conclude that progesterone concentration is highly predictive of ovulation and pregnancy risk in addition to body condition, size of ovulatory follicle, and parity.
Topics: Animals; Cattle; Corpus Luteum; Dinoprost; Estrus Synchronization; Female; Gonadotropin-Releasing Hormone; Insemination, Artificial; Ovulation; Pregnancy; Progesterone
PubMed: 27720155
DOI: 10.3168/jds.2016-11247 -
The Journal of Reproduction and... Apr 2022The reproductive performance of dairy cows has declined, along with an increase in their milk yield. First-service conception rates in lactating dairy cows are often... (Review)
Review
The reproductive performance of dairy cows has declined, along with an increase in their milk yield. First-service conception rates in lactating dairy cows are often lower than 50%. The precise detection of estrus is an important factor in the reproductive management of dairy cows for successful fertilization and pregnancy. However, estrus expression has been decreasing in modern dairy cows, affecting the detection rate of estrus. In addition to estrus, a high incidence of ovulation disorders affects the fertility of dairy cows. To address these problems, it is necessary to understand the changes in the endocrine functions that underlie estrus and ovulation disorders, and to develop effective treatment strategies. Recent studies have revealed that neurokinin B and neurokinin 3 receptor signaling play important roles in the regulation of the secretion of gonadotropin-releasing and luteinizing hormones, suggesting a potential clinical avenue for the stimulation of gonadal function. In this review, I have discussed the problems in estrus and ovulation disorders in modern dairy cows as well as the possible applications of neurokinin 3 receptor agonists in the treatment of these disorders.
Topics: Animals; Cattle; Dinoprost; Estrus; Estrus Detection; Estrus Synchronization; Female; Gonadotropin-Releasing Hormone; Insemination, Artificial; Lactation; Ovulation; Pregnancy; Reproduction
PubMed: 35153250
DOI: 10.1262/jrd.2021-125 -
Journal of Dairy Science Dec 2023This study aimed to determine whether 200 μg of GnRH (gonadorelin hydrochloride) would increase ovulatory response and pregnancies per artificial insemination (P/AI)...
Effect of using 200 μg of gonadorelin at the first gonadotropin-releasing hormone of the breeding-Ovsynch on ovulatory response and pregnancies per artificial insemination in first-service lactating Holstein cows.
This study aimed to determine whether 200 μg of GnRH (gonadorelin hydrochloride) would increase ovulatory response and pregnancies per artificial insemination (P/AI) compared with 100 μg at the first GnRH of the breeding-Ovsynch of a Double-Ovsynch program (DO) in lactating Holstein cows. Weekly cohorts of primiparous (n = 719) and multiparous (n = 1,191) cows submitted to DO (GnRH, 7 d later PGF, 3 d later GnRH, 7 d later GnRH [G1], 7 d later PGF [PG1], 1 d later PGF, ∼32 h later GnRH [G2], and ∼16 h later timed artificial insemination [TAI]) for first service, randomly received either 100 μg or 200 μg of GnRH (gonadorelin hydrochloride) at G1 (primiparous, 64-75 DIM; multiparous, 59-70 DIM). Ovulation was determined by ultrasound 2 d after G1 (n = 1,294) and 2 d after G2 (n = 1,020). Blood samples were collected at G1 and at PG1 d to evaluate serum progesterone (P4) concentrations. Conventional (n = 314, Angus; n = 1,084, Holstein) and Holstein sexed semen (n = 276) were used. Pregnancy was diagnosed on d 32, 46, 88, and 200 post-TAI. The high dose of GnRH (200 μg) increased overall ovulatory response to G1 compared with 100 μg (81.3% vs. 65.1%), being similar between parities (primiparous, 72.2%; multiparous, 73.9%). Mean serum P4 concentrations at PG1 did not differ between treatments (100 µg: 9.59 ± 0.15 ng/mL vs. 200 µg: 9.43 ± 0.15 ng/mL). Cows with no ovulation to G1 had higher serum P4 concentrations at G1 than cows with ovulation to G1 (6.27 ± 0.19 ng/mL vs. 4.66 ± 0.07 ng/mL). At PG1, the proportion of cows with functional corpus luteum (98.7% vs. 89.7%) and serum P4 concentrations (9.68 ± 0.12 ng/mL vs. 9.14 ± 0.22 ng/mL) were greater in cows that ovulated to G1 compared with cows that did not ovulate. Also, cows that ovulated to G1 had a greater increase in serum P4 concentrations from G1 to PG1 than cows with no ovulation (5.26 ± 0.12 ng/mL vs. 3.32 ± 0.25 ng/mL). The high dose of GnRH improved overall P/AI at 32 d post-TAI in cows inseminated with conventional semen (54.6% vs. 48.2%) and tended to improve P/AI on 46 (48.8% vs. 44.9%), 88 (47.6% vs. 43.4%), and 200 (45.3% vs. 41.2%) d post-TAI. Primiparous cows inseminated with conventional semen had better P/AI than multiparous cows at d 32 (58.2% vs. 49.4%), 46 (55.1% vs. 44.4%), 88 (53.2% vs. 43.2%) and 200 (51.6% vs. 40.7%) post-TAI. Primiparous cows treated with 200 µg GnRH had lower P/AI on d 32, 46, 88, and 200 post-TAI when inseminated with sexed semen than with conventional semen. In summary, the higher dose of GnRH at G1 improved ovulatory response and P/AI at d 32 post-TAI and tended to improve P/AI at d 46, 88, and 200 post-TAI in cows inseminated with conventional semen. Moreover, the effect of treatment on P/AI in primiparous cows depended on semen type (conventional vs. sexed semen).
Topics: Pregnancy; Female; Cattle; Animals; Progesterone; Lactation; Estrus Synchronization; Dinoprost; Ovulation; Insemination, Artificial; Gonadotropin-Releasing Hormone; Fertility
PubMed: 37641336
DOI: 10.3168/jds.2023-23416 -
Journal of Dairy Science May 2022Lactating dairy cows are classified as spontaneous ovulators, in which establishment of pregnancy depends on the accuracy of detection of behavioral estrus for correct... (Review)
Review
Lactating dairy cows are classified as spontaneous ovulators, in which establishment of pregnancy depends on the accuracy of detection of behavioral estrus for correct timing of artificial insemination (AI). Development of the Ovsynch protocol, a hormonal protocol that synchronizes ovarian function, thereby allowing for timed AI (TAI) without the need to detect estrus, provided a management tool for increasing AI service rates but not pregnancies per AI (P/AI). A review of 7 randomized, controlled experiments that compared P/AI of cows inseminated after a detected estrus to that of cows receiving TAI after submission to Presynch-Ovsynch or Double-Ovsynch protocols supports that the newest programs for TAI yield more P/AI than cows inseminated after a detected estrus. The physiologic and endocrine mechanisms that explain how fertility programs increase P/AI are a culmination of over 20 yr of research aimed at increasing reproductive performance in lactating dairy cows. We illustrate the dramatic change in reproductive performance of US dairy cows over time by comparing the phenotypic trend in days open with the genetic trend in daughter pregnancy rate and the phenotypic trend in cow conception rate. Whereas days open increased from 1955 to 2000, days open from 2000 to 2010 dramatically decreased without a concurrent increase in the genetic trend for daughter pregnancy rate. By contrast, the dramatic decrease in days open over the past 20 yr is associated with a dramatic increase in the phenotypic trend in cow conception rate. Although many management factors affect P/AI, adoption and implementation of TAI programs that directly increase P/AI is an important component of the dramatic increase in reproductive performance in lactating dairy cows in the United States over the past 20 yr.
Topics: Animals; Cattle; Dinoprost; Estrus Synchronization; Female; Gonadotropin-Releasing Hormone; Insemination, Artificial; Lactation; Ovulation; Pregnancy; Progesterone
PubMed: 35307178
DOI: 10.3168/jds.2021-21431