• Journal of Embryo Transfer
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• v.12 no.1
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• pp.75-90
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• 1997

This study was carried out to establish the techniques for producing the calves of genetically superior Korean Native cattle by transfer of frozen-thawed embryos. The effects of some factors related to embryo recovery following superovulation and pregnancy rate following transfer of frozen-thawed embryos were evaluated. Also calving state was investigated. The results obtained were as follows ; The mean number of total and transferrable embryos recovered per superovulated cow was 8.72 and 4.90, respectively, from a total of 72 superovulations using 34 donor cows. There were no significant differences in the number of total or transferrable embryos recovered per superovulated cow between products of follicle stimulating hormone (FSH), years, seasons, and collection numbers. The pregnancy rate was found 44.44% following transfer of frozen-thawed embryos of Korean Native cattle to a total of 180 recipient cows including 82 Angus, 27 Charolais, 62 Hereford and 9 Korean Native cows. The pregnancy rate was significantly (P<0.05) higher in the transfer of excellent (42.99) and good embryos (40.17%), compared with fair (5.90%) grade embryos. And the pregnancy rate was significantly (P<0.05) higher in the transfer of embryos of morula stage (43.86%) than blastocyst stage (15.51%). But there were no significant differences in pregnancy rates between natural and induced estrus estrus asynchrony of 1 days, breeds, and parities of recipient cows. The normal calving rate of 80 pregnant cows following transfer of frozen4hawed em-bryos was 87.5% and the other 10 pregnant cows showed abortion during the period from pregnancy diagnosis at 50~60 days to calving. The average gestation length of normally delivered recipients was 288.50 days and the average birth weight of 70 calves born was 24.22 kg. The gestation length was significantly (P<0.05) shorter in the recipients delivering female calves (286.70 days) than males (289.39 days). But there were no significant differences in gestation tength and birth weight of calves born between the recipient breeds.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.742-752
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• 2020

Objective: This study investigated the effects of vitamin A (VA) supplementation during late-stage pregnancy on longissimus dorsi muscle tissue development, birth traits, and growth performance of postnatal Korean native calves. Methods: In the preliminary experiment, twenty-six pregnant cattle (initial body weight [BW] = 319 kg (standard deviation [SD] = 30.1; 1st parity) were randomly assigned to the control and treatment groups. The treatment group received VA supplementation at 24,000 IU/d from gestational day 225 until delivery. In the main experiment, twelve pregnant cattle (initial BW = 317 kg [SD = 31.3]; 1st parity) were treated with VA supplementation at 24,000 IU/d (gestational days 150 to 225) and at 78,000 IU/d (gestational day 225 until delivery). Serum VA levels were analyzed in pregnant cattle, and the growth performance, gene expression, and serum VA levels were analyzed in the offspring. Results: Serum VA levels in pregnant cattle decreased the late gestation in both experiments (p<0.001). In the main experiment, pregnant cattle at parturition and offspring at birth in the treatment group had higher serum VA levels than those in the control group (p<0.05). In the treatment groups, an increased birth weight was observed in the main experimental group (p = 0.022), and a tendency (p = 0.088) toward an increased birth weight was observed in the preliminary experimental group. However, no differences were observed in the feed intake, average daily gain, gain-to-feed ratio, or BW of 31-day-old calves. Gene expression was analyzed in longissimus dorsi muscles of 31-day-old calves. VA supplementation in pregnant cattle stimulated postnatal muscle development in offspring by elevating myogenic factor 5 (MYF5), MYF6, and myoblast determination levels (p<0.05). Moreover, preadipocyte-related marker genes such as extracellular signal-regulated kinase 2 and krüppel-like factor 2 were higher in the treatment group than in the control group (p<0.05). Conclusion: VA supplementation (78,000 IU/d) in late-stage pregnant cattle maintained serum VA levels. In addition, 78,000 IU/d VA supplementation increased the birth weight and expression of genes related to muscle and preadipocyte development in offspring. Overall, 78,000 IU/d VA supplementation in pregnant cattle is beneficial to newborn calves.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.247-256
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• 1999

A disease of young Holstein calves characterized by recurrent pneumonia, ulcerative and granulomatous stomatitis, enteritis with bacterial overgrowth, periodontitis, delayed wound healing, persistent neutrophilia and death at an early age had been originally described in 1983 and again in 1987. Most of these calves had stunted growth and a persistent, progressive neutrophilia (often exceeding 100,000/ml). By investigation of pedigrees, all of the affected calves have now been traced to a common sire and confirmed by polymerase chain reaction (PCR) diagnostic DNA testing to be homozygous carriers of a defective allele for bovine CD18. Neutrophils from these calves have several functional deficits and, most importantly, fail to adhere in a ${\beta}_2$-integrin dependent manner. The ${\beta}_2$-integrins represent a family of glycoproteins which participate in various leukocyte adhesion reactions during host defense. The presence or absence of ${\beta}_2$-integrin molecules can be demonstrated on the surface of neutrophils, monocytes and lymphocytes from normal or affected calves using specific monoclonal antibodies and flow cytometry, or by colloidal gold immunolabeling and scanning electron microscopy in backscatter mode. Deficiency of the ${\beta}_2$-integrins on all leukocyte types in Holstein calves is analogous to leukocyte adhesion deficiency (LAD) seen in humans. Neutrophils in bovine (BLAD) and human LAD patients are unable to adhere to the endothelial lining of the cardiovascular system thus interrupting egression of neutrophils into infected tissues. Other leukocytes, while still deficient in expression of the ${\beta}_2$-integrins, are still able to efficiently egress from the blood stream due to interactions of other adhesion molecules that are not as highly expressed on neutrophils. Both BLAD cattle and LAD children (who do not receive bone marrow transplants) often die at an early age as a result of the failure of neutrophils to extravasate into infected tissues. In 1991, Shuster, et $al^{27}$, identified two point mutations within the alleles encoding bovine CD18 in a Holstein calf afflicted with leukocyte adhesion deficiency. One mutation causes an aspartic acid to glycine substitution at amino acid 128 (D128G) in an extracellular region of this adhesion glycoprotein that is highly conserved (> 95% identity) between humans, cattle and mice. The other mutation is silent. Numerous calves with clinical symptoms of leukocyte adhesion deficiency have since been tested and all have been found homozygous for the D128G allele. In addition, calves homozygous far the D128G allele have been identified during widespread DNA testing in the United States. All cattle with the mutant allele are related to one bull, who through artificial insemination (A.I.), sired many calves in the 1950's and 1960's. The carrier frequency of the D128G CD18 allele among U.S. Holstein cattle had reached approximately 15% among active A.I. bulls and 8% among cows. By 1993, the organization of the dairy industry and the diagnostic test developed to genotype cattle, enabled virtually complete eradication of bovine leukocyte adhesion deficiency among current and future A.I. bulls.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.46-51
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• 2011

To examine the seroprevalence of Neospora caninum (N. caninum) infections in cattle raised at farms where an abortion had previously occurred in Gongju city and Yeongi-gun of Chungnam Province, 280 head of cattle from six farms were examined by ELISA. Thirty-two pregnant cattle from four farms were examined to determine the abortion rate in N. caninum-infected pregnant cattle and the infection pattern in newborn calves. The six farms where the abortions had previously occurred demonstrated positive reactions to N. caninum. Although the mean seropositive rate of the six farms was 17.5%, the range of seropisitivity was 3.4-57.1% due to the difference in seroprevalence between farms. The general pattern of seropositivity in cows was higher than in heifers. In addition, the abortion rate of N. caninumpositive in 18 out of 32 pregnant dams raised in four farms was 16.7%. The seroprevalence of newborn calves from N. caninum-positive pregnant animals differed according to the farm but was 86.7% overall. In contrast, 14 newborn calves from the N. caninum-negative pregnant cattle showed negative responses. This suggests that N. caninum is endemic and occurs through vertical transmission from chronically-infected dams. Therefore, aborted dams should be discarded.

• Korean Journal of Veterinary Pathology
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• v.7 no.1
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• pp.17-21
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• 2003

From February to September in 1996, a lot of blind cattle were reported in Dangjin Area of Chungnam Province. Blindness were observed in the 143 calves of the 1,496 calves from 79 farms. Blind cattle were found only in the farms where green pasture was not fed. After administration of vitamin A as the type of feed additives and parenteral injection, the blindness cases were not occurred in those farms. Both pupils were totally dilated with the absence of pupillary light reflex in all blind cattle. In the ophthalmoscopic examination, the fundus revealed multi focal linear white mottling which was more severe in nontapetal fundus than tapetal fundus. Serum vitamin A concentration was as low as 4.1 ,$\mu\textrm{g}$/dl in the calves of the affected farms. Narrowing of optic foramen, retinal degeneration and optic disc atrophy were shown in pathological findings.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.10a
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• pp.37-43
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• 2001

1. About fifty thousand of cattle embryos were transferred and 16000 ET-calves were born in 1999. Eighty percents of embryos were collected from Japanese Black beef donors and transferred to dairy Holstein heifers and cows. Since 1985, we have achieved in bovine in vitro fertilization using immature oocytes collected from ovaries of slaughterhouse. Now over 8000 embryos fertilized by Japanese Black bull, as Kitaguni 7~8 or Mitsufuku, famousbulls as high marbling score of progeny tests were sold to dairy farmers and transferred to their dairy cattle every year. 2. Embryo splitting for identical twins is demonstrated an useful tool to supply a bull for semen collection and a steer for beef performance test. According to the data of Dr. Hashiyada(2001), 296 pairs of split-half embryos were transferred to recipients and 98 gave births of 112 calves (23 pairs of identical twins and 66 singletons). 3. A blastomere-nuclear-transferred cloned calf was born in 1990 by a joint research with Drs. Tsunoda, National Institute of Animal Industry (NIAI) and Ushijima, Chiba Prefectural Farm Animal Center. The fruits of this technology were applied to the production of a calf from a cell of long-term-cultured inner cell mass (1988, Itoh et al, ZEN-NOH Central Research Institute for Feed and Livestock) and a cloned calf from three-successive-cloning (1997, Tsunoda et al.). According to the survey of MAFF of Japan, over 500 calves were born until this year and a glaf of them were already brought to the market for beef. 4. After the report of "Dolly", in February 1997, the first somatic cell clone female calves were born in July 1998 as the fruits of the joint research organized by Dr. Tsunoda in Kinki University (Kato et al, 2000). The male calves were born in August and September 1998 by the collaboration with NIAI and Kagoshima Prefecture. Then 244 calves, four pigs and a kid of goat were now born in 36 institutes of Japan. 5. Somatic cell cloning in farm animal production will bring us as effective reproductive method of elite-dairy- cows, super-cows and excellent bulls. The effect of making copy farm animal is also related to the reservation of genetic resources and re-creation of a male bull from a castrated steer of excellent marbling beef. Cloning of genetically modified animals is most promising to making pig organs transplant to people and providing protein drugs in milk of pig, goat and cattle. 6. Farm animal cloning is one of the most dreamful technologies of 21th century. It is necessary to develop this technology more efficient and stable as realistic technology of the farm animal production. We are making researches related to the best condition of donor cells for high productivity of cloning, genetic analysis of cloned animals, growth and performance abilities of clone cattle and pathological and genetical analysis of high rates of abortion and stillbirth of clone calves (about 30% of periparutum mortality). 7. It is requested in the report of Ministry of Health, labor and Welfare to make clear that carbon-copy cattle(somatic cell clone cattle) are safe and heathy for a commercial market since the somatic cell cloning is a completely new technology. Fattened beef steers (well-proved normal growth) and milking cows(shown a good fertility) are now provided for the assessment of food safety.

• Journal of Veterinary Clinics
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• v.11 no.2
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• pp.561-566
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• 1994

Serum $\alpha$-tocopherol was measured in cattle to evaluate normal range and to investigate the difference of $\alpha$-tocopherol levels between healthy cattle and diseased cattle. Seventy two heads of 1 year old beef Cattle have 429.9$\pm$77.2 $\mu\textrm{g}$/100ml of Serum $\alpha$-tocopherol. The Serum $\alpha$-tocopherol values of calves with diarrhea(8 heads), pneumonia(6 heads) and piroplasmosis(4 heads) were 87.1$\pm$19.2, 126.3$\pm$45.7 and 106.3$\pm$30.9$\mu\textrm{g}$/100ml, respectively. But that of calves in good health (S heads) was 357.t$\pm$68.4 $\mu\textrm{g}$/100m1. And the values of diseased calves are significantly lower an that of calves in good health(p<0.05). Seasonaly, serum $\alpha$-tocopherol levels of dairy Holstein cows were 529.9$\pm$ 120.3(March), 540.2$\pm$127.2(June), 566.9$\pm$149.5(September) and 550,0$\pm$ 125.4(December)$\mu\textrm{g}$/100m1, respectively. The values on autumn was the highest than that of othor seasons. Serum H-tocopherol level of cows with retained placenta was 262.2$\pm$40.6$\mu\textrm{g}$/100m1. And the level of retained placenta was significantly lower than that of healthy cattle regardless seasonal variation(p<0.05).

• Journal of Embryo Transfer
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• v.14 no.3
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• pp.155-162
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• 1999

This study was carried out to establish an effective system for embryo transfer of techniques by analyzing several factors affecting the gestation length and the weight changes of calves produced from embryo transfer in Korean cattle. The results obtained in study on factors affecting the gestation length and the weight changes of calves produced from embryo transfer were as fallow; 1) The gestation length and the birth weight did not differ between male and female, but the weight changes after birth were remarkablely different between sex(P<0.05). 2) The gestation length between heifers and cows was not different, and body weights at birth and 6 months were remarkabley heavy in cows(P<0.05). Weight changes after 6 months were not different. 3) The gestation length and the birth weight were significantly different between the single and twin calving (P<0.05). Weight of twin at 6 and 12 months were remarkabely light. 4) Calving seasons did not affect the gestation length the and the birth weight. Weaning weight was significantly heavy(P<0.05), but weight changes after weaning were no different among the calving seasons. Conclusivley, this results suggest that cows will be better when considering growth of calves and twin produced from embryo trnsfer in Korean cattle.

• Korean Journal of Veterinary Research
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• v.9 no.2
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• pp.37-42
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• 1969

A survey on the Eperythrozoon infection of cattle was conducted by means of examinations of Giemsa staining blood films obtained from 2,263 cattle which had been fed in the middle and south parts of Korea. On the other hand, continuous hematological examinations to five splenectomized calves were performed. The results obtained were summarized as follows: 1. Eperythrozoon wenyoni were detected in the blood films of five cattle from Kyungpook and Cheju areas. 2. The infections of Eperythrozoon wenyoni were observed in four of five splenectomized calves from Taegu and Sungwhan areas. 3. From these results it is considered that the infections of Eperythrozoon wenyoni in cattle are quite common in the middle and south parts of Korea.

• Parasites, Hosts and Diseases
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• v.53 no.2
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• pp.197-200
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• 2015

The prevalence and associated risk factors of Toxocara vitulorum infection in buffalo and cattle calves was studied in 3 provinces in central Cambodia. Fecal samples were collected from 517 calves between the age of 1-15 weeks and processed for nematode egg counts by a modified McMaster method. A total of 64 calves were found to excrete T. vitulorum eggs in their feces (12.4%; 95% exact CI: 9.7-15.5). The mean fecal egg count was 2,798 EPG (SD=16,351; range=0-224,400). A multivariable generalized linear mixed model showed higher odds of T. vitulorum infection for buffalo versus cattle, for animals aged 4-8 weeks versus younger and older ones, and for animals with strongyle infection. There was no association with fecal consistency. Farmers should be aware of the potential impact of T. vitulorum, and treat their calves at the age of 2-3 weeks with anthelmintics such as benzimidazoles or pyrantel.