• Journal of Embryo Transfer
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• v.26 no.4
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• pp.277-282
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• 2011

The present research was carried out to evaluate the possibility of increasing female offspring production ratios using artificial insemination buffer (AIB) before artificial insemination (AI). In this experiment, we optimized AIB composition, made an AIB gun and analyze factors affecting AI non-return rate after AIB treatment. The AIB was made with the base of Tris-buffer supplemented with L-arginine and several other chemicals that might reduce the motility of male sperm compared to the female counterpart, therefore, increasing the possibility of fertilization by female sperm. AIB must be deposited into $2^{nd}$ to $4^{th}$ cervix by AIB gun. After 15 min of AIB deposition, frozen semen was deposited into the same place. A total of 348 cattle were inseminated with AIB insemination, and there were no significant differences between AIB and traditional AI non-return rates (56.8% vs. 55.7%). The AI non-return rate in AIB group, however, differed significantly among 7 Hanwoo farms. The parturition numbers ($1^{st}$ to $7^{th}$) of cows did not affect AIB AI rate. The proportion of AIB AI success rates was significantly higher in Hanwoo cows than in dairy cows (61.0% vs. 48.7%), but the average AI success rate did not differ significantly between AIB and conventional AI (56.8% vs. 55.7%). The female offspring production rate in $2^{nd}$ to $4^{th}$ cervix deposition place was significantly higher than that in the uterus body (77.7% vs. 59.6%, p<0.05). The injection volume of AIB in 5 and 10 ml was significantly higher than that in 2 ml (77.7%, 78.7% vs. 51.8%, p<0.05), but there were no differences in AIB injection volume between 5 and 10 ml. The best exposure time of AIB in the cervix was 10 to 15 min rather than 5 min (79.2%, 77.2% vs. 52.6%, p<0.05). AIB therefore needs to have an exposure time of at least over 10 min for a higher production rate of female offspring. In conclusion, AIB could be used in AI industry to increase the female offspring ratio and AIB AI can increase the AI success rate.

• Journal of Veterinary Clinics
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• v.37 no.5
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• pp.235-241
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• 2020

We aimed to determine the effect of timed artificial insemination (TAI) protocols on the pregnancy rate per insemination and pregnancy loss compared with AI performed at detected estrus in dairy cows and Korean Hanwoo cattle under heat stress. In dairy cattle, 1,250 sets of data that underwent AI during heat stress (temperature-humidity index ≥ 72) were categorized according to their TAI protocols or as controls: 1) PGF_2α-36 h-estradiol benzoate (EB)-36 h-TAI (PG-EB group, n = 113); 2) GnRH-7 days-PGF_2α-56 h-GnRH-16 h-TAI (Ovsynch group, n = 455); or 3) GnRH-6 days-Ovsynch (G6G group, n = 136). The remaining cows underwent AI at detected estrus (AIDE group, n = 546). The probability of pregnancy per AI 45 days after AI was higher (P < 0.01) in the PG-EB (odds ratio [OR]: 1.68), Ovsynch (OR: 1.48), and G6G (OR: 1.79) groups than in the AIDE group. However, the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. In Hanwoo cattle, 617 sets of data inseminated artificially under heat stress were categorized into AIDE (n = 281), PG-EB (n = 194), and combined Ovsynch or G6G (n = 142) groups. The probability of pregnancy per AI 45 days after AI and the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. Thus, implementation of a TAI protocol (PG-EB, Ovsynch, or G6G) in dairy cows under heat stress improves the pregnancy rate per AI versus AIDE, whereas there is no beneficial effect of TAI on the pregnancy rate of Hanwoo cattle under heat stress.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.3
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• pp.329-332
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• 1997

A study on the conception rate of 885 cows and heifers bred under artificial insemination (AI) and natural service was carried out at AI sub-centers. A high conception rate was observed at first service in all breeding methods. It was revealed that the conception rates in AI with liquid semen (LS) were found to be 25.08, 18.58, 12.69, and 2.48% after 1, 2, 3 and 4 services, respectively. Inseminations of cattle with frozen semen (FS) were found to achieve 42.15, 14.46, 5.85, and 2.46% conception rates after 1, 2, 3, and 4 services, respectively. In natural service, conception rates were found to be 62.45, 6.75, 5.91, and 4.64%, respectively, after 1, 2, 3, and 4 services. Insemination of cows and heifers at mid-cycle had significantly (p < 0.05) higher conception rate as compared to early and late cycles. The existing AI machineries and breeding management need to be improved to achieve higher conception rate of dairy cattle under AI.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.87-93
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• 2013

The efficiency of artificial insemination (AI) for horses remains unsatisfactory. It is mainly because each process of AI causes a detrimental effect on semen quality. To sustain quality of semen properly, several factors including libido of stallions and sperm damage during sperm processing and preservation should be considered. Stallions with decent libido produce a high ratio of sperm to seminal plasma in their ejaculates, which is the ideal semen composition for maintaining sperm quality. Thus, to maximize the fertility rate upon AI, stallions should be appropriately managed to enhance their libido. Seminal plasma should have a positive effect on horse fertility in the case of natural breeding, whereas the effects of seminal plasma on both sperm viability and quality in the context of AI remain controversial. Centrifugation of semen is performed during semen processing to remove seminal plasma and to isolate fine quality sperm from semen. However, the centrifugation process can also result in sperm loss and damage. To solve this problem, several different centrifugation techniques such as Cushion Fluid along with dual and single Androcoll-E$^{TM}$ were developed to minimize loss of sperm and to damage at the bottom of the pellet. Most recently, a new technique without centrifugation was developed with the purpose of separating sperm from semen. AI techniques have been advanced to deliver sperm to optimal region of female reproductive tract at perfect timing. Recombinant equine luteinizing hormone (reLH) and low dose insemination techniques have been developed to maximize both fertility rate and the efficiency of AI. Horse breeders should consider that the entire AI procedure should be optimized for each stallion due to variation in individual horses for a uniformed AI protocol.

• Journal of Embryo Transfer
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• v.26 no.1
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• pp.13-17
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• 2011

Research in the area of equine artificial insemination (AI) has led to its increased application in field trials. However, procedures for equine semen collection, cooling and freezing of semen and artificial insemination need further improvement. In experiment 1, we investigated the percentage of total motility (TM) and progressive motility (PM) of sperms at after-collection, cooled-diluted, cooled-transported or frozen-thawed semen. In experiment 2, mares were inseminated with either cooled-diluted, cooled-transported or frozen-thawed semen. In experiment 3, we examined the effect of buffer (skim-milk extender), which was infused into the uterus at the time of AI with frozen-thawed semen. In experiment 4, we compared AI pregnancy rates for mares ovulating spontaneously versus after treatment with hCG. In experiment 1, the average percentage of TM was decreased from 75.3% to 14.4% at the stage of after-collection to frozen-thawed semen (p<0.05). The average percentage of PM was 58.2% and 59.6% at after-collection and cooled-diluted, but it was significantly increased 71.7% after frozen-thawed (p<0.05). In experiment 2, the pregnancy rates after AI using cooled-diluted, cooled-transported and frozen-thawed semen were 60%, 50% and 37.5%, respectively, and similar among treatments. In experiment 3, the pregnancy rate of mares infused with buffer at AI was 40% which was higher than that with no buffer (10%). In experiment 4, the pregnancy rates of mares were similar between ovulated spontaneously (25%) and ovulated with hCG (50%). The results suggest that equine semen that has been cooled-diluted, cooled-transported or frozen can be successfully used to establish AI, pregnancy and foal production. Also, the pregnancy rates after AI can be increased by infusing buffer into the uterus at AI or by inducing ovulation with hCG, but further study is need.

• Journal of Embryo Transfer
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• v.24 no.4
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• pp.289-292
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• 2009

Mongolia has 80% livestock of total agriculture industry, 170,000 farms are engaged, 2,500,000 of cows that were beef and dairy cows are raised. Despite of Mongolian has great application with milk, there are not clear differences between cow and dairy cattle, and the production of milk is also low. But the milk suppliers are varied (horse, sheep, goat, etc), so that the total milk production is 500 thousand ton per year. It's really considerable to improve the breed of owing to many problems with big differences among milk qualities. For carrying out for first year project, artificial insemination project was operated with 3rd grade Holstein semen that were imported from S. Korea, and initiation and field training were also carried out through appropriate AI technique we developed for Mongolia environment. Local information research and MOU conclusion were done with professor D. Altangerel in May $10^{th}{\sim}13^{th}$, 2009, and development for AI technique and AI equipments were supplied for Mongolia breeding and natural environment in July $10^{th}{\sim}17^{th}$ in 2009. All cows were treated by synchronization for AI. To do this, $PGF_{2\alpha}$ injection were treated for luteal phase cow, if it wouldn't work, try again after 11 days. After confirmation of estrus, AI and AI training were carried out with sperm injection in the uterus or cervix by rectum-vagina method which is common worldwide, the most effective artificial insemination technique. If cows were return to next estrus cycle, second AI was carried out about approximately 21 days after artificial insemination. After 2 months, all cows not showing return estrus should be taken pregnancy test. Every pregnant cow will be cared thoroughly. Total 48 cows administrated by $PGF_{2\alpha}$ for synchronization and after 48 hours 45 cows (93.8%) showing estrus were detected and then artificial inseminate them within who 8 cows (27.8%) showed return estrus. Therefore, Using $PGF_2{\alpha}$ for synchronization is effective to use for Mongolia breeding conditions. There are possibility of base for food production after all, including increase of livestock production in Mongolia by improvement of breeding cow with AI and embryo transfer project.

• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.135-138
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• 2007

A 3 year-old female Afghan hound came to the Veterinary Referral Hospital of the College of Veterinary Medicine, Seoul National University for artificial insemination (AI) with frozen semen. In order to inseminate, semen was frozen in USA 3 years ago. Frozen semen was sent by air from Santiago to Seoul for AI. The stud died 2 years ago, so we could only use a limited amount of frozen semen in that estrus cycle. The number of total motile spermatozoa was $59.4{\times}10^6$and the total volume was 1.2 ml. The frozen spermatozoa were thawed in $70^{\circ}C$ water for 8 sec, which were then deposited at the bilateral uterine horns by a surgical method. The number of corpus luteum was 6. Sixty days after artificial insemination resulted in the birth of 4 puppies, all of which are alive and healthy.

• Reproductive and Developmental Biology
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• v.37 no.2
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• pp.75-77
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• 2013

This study was conducted to investigate optimal time of artificial insemination (AI) to Hanwoo female after natural estrus. AI was occurred 12 and 24 hours after natural estrus in both heifer and multiparous recipient then pregnancy and parturition rates were estimated. Results indicated that AI performed at 24 hours after natural estrus showed significant (p<0.05) higher pregnancy rate in both heifer and multiparous recipient groups with significantly (p<0.05) higher abortion rate. However, there are no significant differences of parturition rate, twin birth and sex ratio in both heifer and multiparous recipient groups. Therefore, our results may suggest that performance of AI at 24 hours after natural estrus promise higher pregnancy rate than AI at 12 hours after natural estrus in both heifer and multiparous recipient.

• Reproductive and Developmental Biology
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• v.35 no.3
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• pp.227-232
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• 2011

This survey was conducted to investigate the current status of swine artificial insemination(AI) centers registered as 'semen processing business' in Korea. The survey responses were collected by direct visitation or telephone conversation for 5 months from May through September in 2008. The survey showed that sixty-four AI centers were enrolled in local government and those of fifty-two AI centers were under operation. Forty-nine AI centers surveyed owned a total of 3,334 boars and the Duroc breed accounted for the highest rate(73.1%) of all boar breeds. In type of ownership, agricultural management corporations was the highest(42.3%) and followed by private ownership(34.6%). Large-scale AI centers in terms of own over 151 boar were surveyed as 5.9% and most AI centers own less than 100 boars(86.5%). The average number of boars per AI center was 68. The amount of liquid semen provided by 52 AI centers were 1,791,000 doses and each AI center provides average of 39,000 does, which is represented for 90% consumption by sows in Korea.

• Journal of Embryo Transfer
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• v.25 no.4
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• pp.237-245
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• 2010

Only an optimum number of viable spermatozoa in a frozen-thawed insemination dose can ensure conception at artificial insemination (AI). We report here the percentages of normal, abnormal and viable spermatozoa present in the frozen-thawed semen of 20 Black Bengal bucks used for commercial AI. Bucks in this experiment were of 19.3~46.1 months old and 25~42 kg body weight. Four semen straws (0.25 ml) from each buck were collected for evaluation of their kinetic parameters. Scrotal circumference was measured by using a scrotal tape, sperm motility was estimated on eye estimation and sperm concentration was determined by using a haemocytometer. Sperm morphology was studied in paraformaldehyde fixed spermatozoa under differential interference contrast (DIC) microscope. To determine the proportion of live (plasma membrane intact) spermatozoa, semen was stained with SYBR-14 and propidium iodide and examined under fluorescent microscope. Scrotal circumference, post-thaw sperm motility, sperm concentration per insemination dose and proportion of normal spermatozoa were $21.5{\pm}0.7\;cm$, $43.5 {\pm}5.4%$, $83.5{\pm}6.7$ million and $88.3{\pm}4.1%$, respectively. The percentages of spermatozoa with head shape and acrosome abnormalities were lower ($2.7{\pm}1.1$ and $1.4{\pm}1.3$, respectively), whereas higher percentages of abnormalities ($7.0{\pm}1.8$) were observed in mid piece and tail portion. The proportion of live spermatozoa was $28.5{\pm}5.4$. It is concluded that although a good number of morphologically normal spermatozoa are present in the insemination dose, the proportion of live spermatozoa is low, which warrants further improvements of buck semen freezing procedures to ensure good quality at AI.