• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.932-936
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• 2014

Breeding records of 57 Arabian and 66 Thoroughbred mares were analysed to assess their reproductive performance under the subtropical conditions of Pakistan. The Arabian mares showed significantly higher conception rates (p<0.05) in second mated oestrus and foal heat mated oestrus compared to Thoroughbred mares. However, conception rates for first lifetime mated oestrus were similar in both breeds of mares. Age at first mating ($1,301{\pm}40$ vs $1,500{\pm}32$ days) was significantly (p<0.05) less in Arabian compared to Thoroughbred mares. Both breeds of mares showed significantly (p<0.05) higher frequencies of oestrous cycles and conception rates during the winter (October to March) compared to summer (June to August) months. Age of mares affected the conception rates, as mares at ages 3 to 7 and 8 to 12 years of ages had significantly higher conception rates (p<0.05) than those ${\geq}18$ years old in both breeds. This study demonstrates that i) reproductive performance in Arabians is better than Thoroughbred mares under the subtropical conditions of Pakistan, ii) mares remain cyclic throughout the year and iii) conception rates were higher in mares bred during winter compared to summer months.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.2
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• pp.171-176
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• 2020

Advancing the estrous cycle of mares is an essential breeding strategy that is routinely conducted by Thoroughbred breeders to improve economic outcomes. For this purpose, Equilume light masks have been developed as an alternative to existing technologies such as artificial lighting or hormonal treatments because they are considered as valid as existing methods with additional animal welfare advantages. For example, with the Equilume light masks, horses can be let out into the pasture, whereas they have to be kept indoors during lighting treatment. Because the function of Equilume light mask on the estrous cycle of mares is influenced by environmental factors such as nutrition condition and temperature, Equilume light mask should be studied in various environments. The objective of the present study was thus to verify the effect of Equilume light masks on the onset of the estrous cycle in Thoroughbred mares in South Korea. Mares were randomly selected and separated into two groups at two Thoroughbred horse breeding farms. The mares in the treatment group were equipped with Equilume light masks from November 18 to February 10 the following year. The body condition, the number and size (> 35 mm) of uterine follicles, and the uterine horn score of the mares were assessed on January 6 and February 10. The body condition scores were not different between the two groups. The treatment with the Equilume light mask had no positive effects on developing follicles and the reproductive tract. In conclusion, the use of Equilume light masks did not influence the seasonal resumption of the estrus cycles in Thoroughbred mares in South Korea.

• Korean Journal of Veterinary Research
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• v.42 no.4
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• pp.469-473
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• 2002

This study was carried out to investigate the blood groups(Aa, Ca, Dc, Qa, Ua) and antierythrocyte antibody associated with neonatal isoerythrolysis(NI) in Thoroughbred horses. The blood groups from 1,351(35 stallions, 1,316 mares) Thoroughbred horses tested by serological procedures, and antierythrocyte antibody from 52 mares by indirect antiglobulin test. The blood groups(factor) of Aa, Ca, Dc, Qa and Ua positive were 97.1%, 100%, 91.4%, 82.9%, and 17.1% in stallions, respectively, and were negative 3.5%, 6.2%, 25.1%, 18.3%, and 77.1% in mares, respectively. These mares are considered to be at risk for production of an NI foals. The antierythrocyte antibody was not detected by this technique in all mares. These results suggest that the all breeding mares without blood groups Aa(3.5%) and Qa(18.3%) should be selected a appropriate stallion to prevent of neonatal isretythrolysis during the breeding season in Thoroughbred horses.

• Korean Journal of Veterinary Research
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• v.44 no.1
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• pp.105-111
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• 2004

A total of 301 Thoroughbred mares were investigated the characteristics of breeding in the local areas in Jeju during the period from February 2000 to July 2001. The pregnancy rate and foaling rate in 143 mares were 93.0%, 72.0%, respectively, and mean gestational length was 339.3 days in 2000. The pregnancy rate in 158 mares was 86.7% in 2001. Mature follicles were ovulated in right(46.0%), left(45.2%), and bilateral(7.8%) ovary. The incidence of multiple pregnancies in 158 mares between 15 days and 45 days after mating were 89.3%(single), 10.1%(twin), and 0.6%(triple). The incidence of EED was 13.3%. Also uterine cyst and fluid had an bad influence on mare's pregnancy. These results suggest that regular monitoring of the pregnancies and maintaining of good uterine condition improve the pregnancy rates and foaling rates during breeding season.

• Journal of Veterinary Clinics
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• v.24 no.1
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• pp.19-25
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• 2007

This study carried out to investigate the genital tract bacterial flora of Thoroughbred mare in Jeju province during March and July, 2006. The specimens were collected from vaginal ucosa and clitorial fossa using a culture swab (BBL, USA) from 100 Thoroughbred mares. Colonies were selected blood and MacConkey agar plate, and identified as standard biochemical properties using Biolog system (Thermo, USA). In this study, 470 gram-negative strains were isolated more frequently than 249 gram-positive strains. We were Isolated Escherichia coli (19.8%), Proteus mirabillis (14.9%), Enterobacter nimipressuralis (7.4%), Enterobacter mobilis (4.7%), Aeromonas encheleia (4.3%), Pseudomonas aeroginosa (3.0%), Staphylococcus aureus (14.9%), Staphylococcus epidermidis (11.2%), Coagulasenegative Staphylococcus spp. (10.0%), Enterococcus faecalis (9.2%), Enterococcus faecium (8.0%), Actinomyces viscosus (7.2%), Micoroccus diversus(6.8%), Streptococcus dysgalactiae subsp. equisimilis(5.2%), Streptococcus equi subsp. zooepidemicus (3.2%), Other non-beta hemolytic Streptococcus spp. (2.0%) and many others from vaginal mucosa and clitorial fossa in Thoroughbred mares. No significant bacteria (Taylorella equigenitalis and Klebsiella pneumonia) were isolated from the mare genital tract. In antimicrobial agents susceptibility test, it shows a high sensibility in the antibiotics of the most which excepts the streptomycin and neomycinm, kanamycin, spectinomycin, compound sulfonamides. Especially, Staphylococcus epidermidis, Enterococcus spp. and Streptococcus spp. were visible a high sensibility in the all antibiotics. However, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus spp. and E. coli were showed a high antibiotic resistance patterns. These results may provide the basic information to establish strategies for the treatment and prevention of reproductive disease in Thoroughbred mares in Korea.

• Journal of Veterinary Clinics
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• v.20 no.1
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• pp.121-130
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• 2003

The purpose of this study was to investigate the effect of breeding conditions on reproductive efficiency of thoroughbred broodmares by ultrasonography. The mean age and breeding career of 120 mares used in this study were 11 years old and 6 years, respectively. The average pregnancy rate and embryonic loss rate were 87.5%, 11.8%. The groups that were 8-10 years old, 4-6 years, maiden and mated on May showed the highest pregnancy rate. While mares mated on 1st estrus post partus had the highest ovulation rate but showed the highest embryonic loss rate and he lowest pregnancy rate. And broodmares that had more intrauterine foreign bodies such as cyst and fluid with age and breeding career had represented lower pregnancy rate and higher embryonic loss rate than those having normal uterine condition. These results suggest that the breeding condition and uterine environment of mares had a significant influence on reproductive efficiency.

• Journal of Veterinary Clinics
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• v.15 no.2
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• pp.358-363
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• 1998

These studies were performed to investigate what genital diseases could be diagnosed by ultrasonography in the mares associated with infertility. Of 159 thoroughbred breeders(4 to 18 years old), 31 mares which had been considered as the mares with reproductive disorders were examined by ultrasonography during the breeding season. 1. Hematoma in ovarian disordersl endometritis and pyometra in uterine disorders could be diagnosed by ultrasonography. 2.The rate of infertility was 19.5% out of 159 breeders and the rate of uterine disordres was 71.0% among the whole reproductive disorders. 3.Of 31 mares considered as the mares with infertilityi 26 mares were diagnosed by ultrasonography denoting 83.9% of diagnosis rate. 4.The highest average age of mares among the mares with reproductive disorders was 11.7 years in the mares with uterine disorders. The average age of the mares diagnosed as concepted was 7.5 years, which was much lower than that of the mares with reproductive disorders.5.Crushing one of twin vesicles was confirmed by ultrasonography. In conclusions ultrasonography was feasible for diagnosis of the mares with reproductive problems.

• Journal of Veterinary Clinics
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• v.21 no.2
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• pp.115-121
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• 2004

The purpose of this study was to ascertain the breeding efficiency in Thoroughbred mare. A total of 106 mares were investigated for the status of follicle (462 cases), ovulation (179 cases) and pregnancy (346 cases). Of total examination, 46.8% was follicle measure to determine breeding time, and mating rate per cases examined was 39.9%. There was no correlation between reproductive results and size of follicles or endometrial edema or degrees of teasing alone. 143 cases were ovulated among 179 cases which were performed ovulation examination, and ovulation rate and fertilization rate per mating times were 79.9% and 39.0%, respectively. The use of hCG(human chorionic gonadotropin), to facilitate ovulation, presented to increase occurrence of double ovulations and twin fertilizations In conclusion, though more examination to estimate the optimal breeding time and higher mating rate was performed, fertilization rate per mating times was lower and then reproductive efficiency also became decreased. Therefore, it seemed that accurate examination of reproductive tracks, appropriate teasing programme and hCG administration before ovulation were of help to improve ovulation rate and fertilization rate.

• Journal of Embryo Transfer
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• v.22 no.1
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• pp.47-51
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• 2007

The objective of this study was to improve the reproductive ability of Thoroughbred mares with artificial estrous regulation by hormone treatments and artificial illumination. The results were as follows; Estrous detection in cycling mares which were treated $PGF_2{\alpha}$ or altrenogest administration was all 100%, and pregnancy rates were 95.2% and 71.4%, respectively. Estrous detection was 100% within March when altrenogest was administered alone or together with estradiol for non-pregnant mares in the previous year. Interval to estrous detection after altrenogest administration was 4.3 days in single administration of altrenogest and 3.7 days in combined administrations of altrenogest and estradiol, respectively Interval to ovulation after estrous detection were 2.7 and 2.5days, respectively. Pregnancy rate following single altrenogest administration was 80.0%. Estrous detection and pregnancy rates by artificial illumination in non-pregnant mares were 92.9% and 46.9%, respectively. These results show that estrous synchronization of mares during breeding season will be able to improve the pregnancy rate, and altrenogest administration in non-pregnant mares in the previous year will be able to induce early reproduction and improve pregnancy rate In racing horses.

• Journal of Animal Science and Technology
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• v.64 no.1
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• pp.1-9
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• 2022

Equilume light masks had no impact on hastening the resumption of estrous cyclicity in mares maintained in outdoor pastures on the mainland of Korea due to the cold weather conditions. Jeju Island is a major horse-breeding site in Korea and is warmer than the mainland during the winter season. Therefore, the primary objective of this study was to explore the efficiency of the Equilume light mask on the resumption of seasonal estrous cycles in Thoroughbred mares on Jeju Island. A total of 20 nonpregnant mares were randomly divided into the Equilume light mask (n = 9) and stable lighting (n =11) groups. The experiment was performed at seven different horse-breeding farms located on Jeju Island from November 15, 2020, to February 15, 2021. The mares were exposed to the respective lights from 16:00 to 23:00. Follicle size and uterine edema were measured by ultrasound scanning. Body condition scores (BCS) were also monitored during the experiment. Statistical analysis was conducted using the SAS and SPSS software, and p-values of < 0.05 were considered statistically significant. Two of the nine (22.2%) mares in the Equilume light mask group and three of the 11 (27.28%) mares in the stable lighting group were still cycling in December and January, which were considered as all-year-round cycling mares. On February 15, there was no difference between groups in the resumption of early seasonal estrus cycle, which was determined by follicles > 25 mm in addition to uterine edema. All mares in the Equilume light mask group and five of the eight mares (62.5%) in the stable lighting group had resumed cycling. Interestingly, six of the seven mares (87.5%) in the Equilume light mask and four of eight mares (50%) in the stable lighting group had already ovulated on February 15 (p > 0.05), as determined by the presence of a recent corpus luteum. No difference was observed in BCS and uterine edema between groups (p > 0.05). In conclusion, the Equilume light mask can be an effective approach to induce early seasonal estrus cycles of mares in Jeju Island, and it also enhances the efficiency of farm management by reducing labor.