Recently, two strains of a novel enterohepatic Helicobacter species, H. equorum, were isolated from fecal samples of two clinically healthy horses in Belgium. The purpose of the present study was to detect the presence of H. equorum infection in fecal samples of adult horses from Jeju Island using polymerase chain reaction (PCR). A total of 86 fecal samples from 31 clinically healthy Thoroughbred horses and 55 horses native to the Jeju Island were evaluated. H. equorum DNA was detected in 10.9% (6/55) of the native-horses, while all the Thoroughbred horses showed negative PCR results. Ages of the H. equorum DNA-positive horses ranged from 2 to 4 years old. To the best of our knowledge, this is the first study of H. equorum detection in fecal samples from horses in Korea.

vThis study analyzed the coat color-related genes of MC1R, ASIP, ECA3-inversion, and STX17 of 1,462 Jeju horses administered by the Jeju Special Self-Governing Province. This was done to investigate the distributional characteristics of coat color-related genes in the Jeju horse group and the changes of its coat color-related genes by generation. The genotype frequency of the MC1R gene of E+/E+ and E+/Ee related to black coat color was 0.122 and 0.447, respectively, while Ee/Ee of the chestnut genotype was 0.429. The genotype frequency of the ASIP gene of AA/AA, AA/Aa, and Aa/Aa was 0.46, 0.448, and 0.091, respectively, where the genotype frequency of Aa/Aa turned out to be relatively low. The To/To and +/To genotype that manifests the Tobiano shape was 0.001 and 0.119, respectively, with the share of Tobiano shape around 12%. The genotype frequency of G/G and G/g of STX17 related to grey coat color was 0.002 and 0.680, respectively, with the share of grey horses among the Jeju horse group at 68.2%. As for the change of coat color genes by generation, no large changes were observed in the MC1R and ASIP genes. In ECA3-inversion, the To allele that manifests Tobiano significantly decreased following the generational change (p<0.05), while the STX17 G allele related to grey coat color significantly increased following the generational change (p<0.05). It will be necessary to examine the coat color genes when selecting breeding horses so that the diversity of coat colors among the Jeju horse group can be maintained.

This study was conducted to evaluate the chemical composition and physico-chemical meat quality properties for Jeju-horse (Jeju-horse×Thoroughbred) with different fattening periods (4-, 8- and 13.5-month). In chemical composition, the moisture contents were decreased as the fattening periods increased. The fat contents were 3.78% at 4-months and they were decreased such as 70∼76% at 13.5-months whereas the protein contents increased as the fattening period increased. The cooking loss was highest (33.41%) at 4-months group and decreased after that periods, however, there was no significant difference among 3 fattening period groups. The Warner-Bratzler shear force (WBS) values were lowest at 4-months group and tended to increase as the fattening period increased. In mineral contents, the contents of Fe, Na, Zn were significantly higher for 4-month group than 8- and 13.5-month group whereas the contents of Mg were significantly lower for 4-month group than 8- and 13.5-month group (p＜0.05). The results of the amino acid composition analysis showed that cystein, methionine, threonine, serine, glutamic acid, alanine, valine, lysine, histidine, arginine contents were significantly increased and tyrosine contents were significantly decreased as the fattening period increased (p<0.05). The contents of palmitic acid (C16:0) were highest at 4-month group and they decreased as the fattening period increased (p＜0.05). The contents of oleic acid (C18:ln9) were highest at 8-month group and they were lowest at 13.5-month group. The total contents of unsaturated fatty acids were significantly higher for 13.5-month group than those for 4-month groups (p＜0.05). In conclusions, the fat contents were decreased whereas the protein, Fe, Mg contents and WHC increased as the fattening periods increased. Overall contents of amino acids increased only except several amino acids. The total contents of unsaturated fatty acids were increased as the fattening period increased, however they were not significantly different when those were fattened more than 8-month. These results indicated that longer fattening period could be more effective to enhance horse meat quality.

Horses are non-ruminant and monogastric animal. If concentrates are fed plentifully at a time, undigested starch reaches large intestine and it activates amyloytic bacteria. Finally, it lowers a pH level and causes colic. Therefore, standard feed of concentrates and period of feed are important factors to fat up horses. This study was conducted to evaluate the productivity and carcass quality, quantity grade for Jeju horse (24 month old) with different fattening periods (4-, 8- and 13.5-month). The body weights were increased as the fattening periods increased and the increase rate was highest at 4-month group. The daily weight gain was decreased as the fattening periods increased such as 0.46 kg for 4-month group, 0.39 kg for 8-month group and 0.34 kg for 13.5-month groups. The daily intake was increased as the fattening periods increased such as 4.42 kg for 4-month group, 5.00 kg for 8-month group and 5.26 kg for 13.5-month groups. The daily feed conversion was increased as the fattening periods increased such as 11.71% for 4-month group, 17.69% for 8-month group and 18.53% for 13.5-month group. The backfat thicknesses and loin-eye areas were 3.50 mm, 83.50 ㎠ and increased to 4.20 mm, 94.00 ㎠ until they were fattening up for 8-month then they were decreased to 4.00 mm, 89.40 ㎠ when they were fattening up to 13.5-month. There was no significant difference in the meat color among 3 fattening groups, however, the a-values (redness) of meat color and b-values of fat color were highest (5.0 and 3.80, respectively) for 13.5-month group. The texture was not significantly different among 3 fattening groups. The maturity levels were in the 3.8∼4.5. All horses used in the experiment had the quality grade 2 and the horses for 13.5-month group had the quantity grade A, whereas the horses for 4-month group had the quantity grade B or C. Jeju horse had the low quality grade (quality grade 2) although the carcass yield increased when they were fattened from 24 month to 37.5 month.

제주마 경주 능력 개량을 위한 기초 자료 확보를 위하여 혈통 정보량과 오류량이 유전 모수 추정에 미치는 영향을 분석하였다. 혈통 자료는 램덤으로 혈통 정보의 삭제(0~25%) 또는 오류 유발(0~25%)과 각 수준별 20회 반복으로 모의자료를 형성하였다. 분석에 이용된 형질은 제주마 1,000m 경주의 주파 시간을 이용하였고, 상가적 유전 분산의 추정은 DF-REMLAI 알고리즘을 이용하였다. 개체의 양부모에 대한 정보 유실량과 오류량의 증가는 선형적인 회귀관계로 상가적 유전 분산 성분(유실 b = -0.079, 오류 b= -0.114)과 유전력 추정치(유실, b= -0.006; 오류, b = 0.008)의 감소를 초래했다(p＜0.01). 특히 개체의 양부모에 대한 정보유실보다는 정보 오류가 상가적 유전분산량과 유전력 추정치를 보다 크게 왜곡하는 것으로 나타났다. 부 또는 모에 대한 정보의 유실과 오류의 증가도 대부분 오차 분산 성분과 영구 환경 분산 성분의 증가를 유발시키고, 상가적 유전 분산성분의 감소를 가져왔다. 원자료에서 얻은 모수를 기준으로 했을 때 양부모에 대한 정보의 유실량과 오류량이 1% 증가함에 따라 유전력은 각각 0.92% 및 1.39%씩 낮아지는 관계를 보였다 (p＜0.01). 제주마의 1,000m 주파 속도에 대한 유전력은 0.60으로 추정되었지만, 초기 집단에 존재하는 혈통 정보의 누락 및 오류를 고려한다면 실제보다도 10% 정도는 낮게 추정되고 있다고 사료되었다. 이와 같은 결과는 상가적 유전 분산량의 감소는 물론, 선발에 따른 제주마의 경주 능력에 대한 유전적 개량량에도 영향을 줄 것으로 판단된다.

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-ETM 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.

본 연구는 제주지역에서 말 방목에 적합한 혼파조합을 선발하기 위해 해발 450m에 위치한 한국마사회 경주마육성목장에서 티모시, 오차드그라슨 페레니얼 라이그라스 화본과 위주 초종으로 혼파 파종하여 2년 간 말(더러브렛)을 방목하면서 목초생산성, 식생변화 및 채식율 변화 등을 구명하기 위해 수행되었다. 연간 총 건물생산량은 1, 2차년도에 관계없이 혼파조합 간 유의적인 차이를 보이지 않았으나 시기별에 따라 생산량 차이를 보였다. 식생은 페레니얼 라이그라스가