• Journal of Animal Science and Technology
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• v.63 no.2
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• pp.426-439
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• 2021

It is already well known that castration improves marbling quality but exact timing of castration is still highly debated in beef cattle production industry. After castration, blood hormonal changes occur in steer and objective of this study was to investigate the effects of growth hormone (GH) levels on adipocyte differentiation in stromal vascular cells (SVCs) and transdifferentiation into adipocytes in C2C12 myoblasts. Total GH concentrations were measured via enzyme-linked immunosorbent assay (ELISA) in 24 male calves and 4 female calves. Cell proliferation, cellular triglyceride (TG) accumulation, and the cell's lipolytic capability were measured in C2C12 myoblasts and SVCs. Myogenic, adipogenic, and brown adipocyte-specific gene expression was measured via real-time polymerase chain reaction (PCR) using SYBR green. Serum GH levels were the highest in late-castrated calves. Treatment with 5 ng/mL GH resulted in greater TG accumulation as well as increased CCAAT-enhancer-binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ expression compared to that after treatment with 15 ng/mL GH. Treatment with 5 ng/mL GH also resulted in lower myogenin (myo)G and myoD expression compared to that after treatment with 15 ng/mL GH. The expression of bone morphogenetic protein (BMP) 7 after treatment with 5 ng/mL GH was higher than that after treatment with 15 ng/mL GH. But carcass characteristics data showed no significant difference between early and late castrated steers. Therefore, our results indicate that castration timing does not seem to be inevitable determinate of carcass qualities, particularly carcass weight and marbling score in Hanwoo beef cattle.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.2
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• pp.106-110
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• 2019

Sexed sperm can contribute to increase the profitability of the cow industry through the production of offspring of the craved sex, such as males for meat or females for dairy production. Therefore, the utilization of sexed sperms plays a very important role in the production of offspring of superior cattle. In this study, we examined the pregnancy rates and calves sexing proportion of male and female calves produced using AI, both performed using sexed and conventional sperm. In the result, the conception rates after ET were 73.3% (33/45) sexed semen and 52% (55/104) conventional semen. Thus, the sex ratio for sexed-semen inseminations was 70% (21/30) females for singleton births within a 272 to 292 day gestation interval. The sex ratio for conventional semen was 61% (34/56) females for births. As a result, it is suggested that the use of sex classification sperm will play a very important role in the offspring production of Korean bovine.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.1
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• pp.22-27
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• 2012

The experiment involved observations of 2,514 Holstein-Friesian cows to determine the effects of environmental factors (cow's age, calving season, weight and sex of calves, housing system) and genetic factors on gestation length in dairy cattle and the correlation between gestation length and other reproductive traits (calving ease, stillbirth rates and placental expulsion). Genetic parameters were estimated based on the sires of calved cows (indirect effect) and the sires of live-born calves (direct effect). The following factors were found to contribute to prolonged gestation: increasing cow's age, male fetuses and growing fetus weight. Optimal gestation length was determined in the range of 275-277 days based on calving ease and stillbirth rates. The heritability of gestation length was estimated at 0.201-0.210 by the direct effect and 0.055-0.073 by the indirect effect. The resulting genetic correlations suggest that the efforts to optimize (prolong) gestation length could exert an adverse influence on the breeding value of bulls by increasing perinatal mortality and calving difficulty. The standard errors of the investigated parameters were relatively high, suggesting that any attempts to modify gestation length for the purpose of improving calving ease and reducing stillbirth rates should be introduced with great caution.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.539-545
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• 1993

This study was carried out the determine the progesterone concentration for serum by enzyme-linked immunosorbent assay(ELISA) in bovine adult at estrous, pregnant, after patuation and male, female calves of 1 month old, respectively. The results obtained were summarized as follows ; 1. The assay has a sesitivity of $0.1ng/m{\ell}$. 2. Intra and inter-assay coefficient of variation were 4.5%, 6.1~9.4% when used for the determination of progesterone in samples of bovine serum. 3. The percentages of recovery for progesterone added were between 88.0 to 88.9%. 4. Progesterone concentration of adult bovine serum at estrus, pregnant and after 1 day of parturition were $0.37{\pm}0.16$, $7.1{\pm}1.0$, $0.13{\pm}0.02ng/m{\ell}$, respectively. 5. There was no differences in serum progesterone concentration of calves both male($0.16{\pm}0.03ng/m{\ell}$) and female($0.15{\pm}0.04ng/m{\ell}$) on 1 month old. From these results, progesterone determination by ELISA is very applicable to detect of early pregnancy diagnosis, factorial analysis of reproductive disorder, and also reproductive physiological functions such as veterinary therapeutic measures and monitoring of cyclicity.

• Reproductive and Developmental Biology
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• v.29 no.4
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• pp.235-239
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• 2005

This study was conducted to test whether the transgenic cattle pass the transgene to their progeny through germ cells, and whether the transgene is expressed in the mammary gland of ransgenic cows. Two male ransgenic calves were born from IVF-derived embryos injected with bovine $\beta-casein/human$ lactoferrin fusion gene and then grew up to be reproducible. Semen was collected from a transgenic bull after 18 mon of age and then frozen. Bovine oocytes matured in vitro were fertilized with spermatozoa of the transgenic bull and cultured in $50\;{\mu}L$ drops of CRlaa medium supplemented with 3 mg/mL BSA. After 48 h of culture, cleaved embryos were determined for the presence of transgenes by DNA polymerase chain reaction (PCR). Proportion of transgene positives among bovine embryos fertilized with sperm of the transgenic bull was $20.9\%$ (28/134). One of transgenic bulls did not produce transgenic sperm. Out of 34 calves produced from recipient heifers inseminated with semen of the other bull, 3 $(8.8\%)$ were transgenic animals (2 females and 1 male). Thus, one transgenic bull showed a low transmission frequency below Mendelian levels in both the IVF-derived embryos and his progeny. It was demonstrated by Southern blot that copy numbers of the transgene in the transgenic progeny enhanced about 1.8 times as compared to those of the founder bull The results demonstrate that the transgenic bull carrying human lactoferrin gene could pass his transgene to the progeny through germ cells, although he is a germ-line mosaic.

• Korean Journal of Veterinary Service
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• v.29 no.4
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• pp.493-496
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• 2006

This study investigated cases of progressively necrotizing limbs in Korean indigenous calves. The recent case (Case 1) involved a 3-month old, male calf in Jeonbuk province that presented a visibly dry form of gangrene affecting joints of the forelimbs and the hind limbs. Radiograph revealed osteoarthritis possibly resulting from pressure of disrupted joint skin, fasciae, deeper underlying musculatures and tendon. Histopathology of affected tissue showed necrotizing; severely thrombosed dilated blood vessels with rechanneling microvasculatures. The lack of substantial infectious inflammatory exudates in the vital organs and the inability to respond to antimicrobial treatment bolstered the notion that the observed thromboembolic and vascular lesion was attributed to possible vasoconstrictive effects of ergot alkaloids. Case 2: A previously encountered similar case in a 4-month old, male calf showing gangrene of hind limbs and posterior ataxia was likewise presented. These two cases were impressed as probable ergotism. Ergotism may be uncommon or underreported in Korea. Future isolation of ergot alkaloids in feeds or in pasture is highly suggested.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.2
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• pp.80-86
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• 2022

The ability to determine the sex of bovine embryos before the transfer is advantageous in livestock management, especially in dairy production, where female calves are preferred in milk industry. The milk production of female and male cattle benefits both the dairy and beef industries. Pre-implantation sexing of embryos also helps with embryo transfer success. There are two approaches for sexing bovine embryos in farm animals: invasive and non-invasive. A non-invasive method of embryo sexing retains the embryo's autonomy and, as a result, is less likely to impair the embryo's ability to move and implant successfully. There are lists of non-invasive embryo sexing such as; Detection of H-Y antigens, X-linked enzymes, and sexing based on embryo cleavage and development. Since it protects the embryo's autonomy, the non-invasive procedure is considered to be the safest. Invasive methods affect an embryo's integrity and are likely to damage the embryo's chances of successful transformation. There are different types of invasive methods such as polymerase chain reaction, detection of male chromatin Y chromosome-specific DNA probes, Loop-mediated isothermal amplification (LAMP), cytological karyotyping, and immunofluorescence (FISH). The PCR approach is highly sensitive, precise, and effective as compared to invasive methods of farm animal embryonic sexing. Invasive procedures, such as cytological karyotyping, have high accuracy but are impractical in the field due to embryonic effectiveness concerns. This technology can be applicable especially in the dairy and beef industry by producing female and male animals respectively. Enhancing selection accuracy and decreasing the multiple ovulation embryo transfer costs.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.7
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• pp.971-978
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• 2016

The aim of this study was to evaluate the effect of replacing corn grain for sugar cane molasses (MO) or glucose syrup (GS) in the starter concentrate on performance and metabolism of dairy calves. Thirty-six individually housed Holstein male calves were blocked according to weight and date of birth and assigned to one of the starter feed treatments, during an 8 week study: i) starter containing 65% corn with no MO or GS (0MO); ii) starter containing 60% corn and 5% MO (5MO); iii) starter containing 55% corn and 10% MO (10MO); and iv) starter containing 60% corn and 5% GS (5GS). Animals received 4 L of milk replacer daily (20 crude protein, 16 ether extract, 12.5% solids), divided in two meals (0700 and 1700 h). Starter and water were provided ad libitum. Starter intake and fecal score were monitored daily until animals were eight weeks old. Body weight and measurements (withers height, hip width and heart girth) were measured weekly before the morning feeding. From the second week of age, blood samples were collected weekly, 2 h after the morning feeding, for glucose, ${\beta}$-hydroxybutyrate and lactate determination. Ruminal fluid was collected at 4, 6, and 8 weeks of age using an oro-ruminal probe and a suction pump for determination of pH and short-chain fatty acids (SCFA). At the end of the eighth week, animals were harvested to evaluate development of the proximal digestive tract. The composition of the starter did not affect (p>0.05) concentrate intake, weight gain, fecal score, blood parameters, and rumen development. However, treatment 5MO showed higher (p<0.05) total concentration of SCFAs, acetate and propionate than 0MO, and these treatments did not differ from 10MO and 5GS (p>0.05). Thus, it can be concluded that the replacement of corn by 5% or 10% sugar cane molasses or 5% GS on starter concentrate did not impact performance, however it has some positive effects on rumen fermentation which may be beneficial for calves with a developing rumen.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.12
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• pp.1881-1889
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• 2018

Objective: In dryland areas of China, alfalfa hay (AH) is a possible substitute for concentrate feed for beef cattle. To evaluate the potential benefits of this substitution, we studied the effect of the ratio of AH intake to total dry matter (DM) intake on average daily body-weight gain (ADG), dietary energy utilization status, and economic benefit in Gansu province. Methods: In each of two feeding trials in 2016 (trial 1 [T1], July 3 to 17; trial 2 [T2], August 15 to September 23), crossbred male Simmental calves were allocated to low AH (LA), medium AH (MA), and high AH (HA) feeding groups (n = 4 per group). The target ADG was set as 1 kg for both trials. In a one-way-layout design based on conventional feeding practices in the province, calves received diets containing the different AH amounts, with a constant ratio of corn stover:total DM and decreasing rations of concentrate feed proportional to the increase in AH. Calves in T1 received AH at 15% (T1-LA), 23% (T1-MA), or 31% (T1-HA) of their dietary DM allowances; those in T2 received 9% (T2-LA), 24% (T2-MA), or 34% (T2-HA) AH. Results: Among the T1 groups, both ADG and economic benefit were highest in T1-LA; whereas in T2, they were higher in the T2-LA and T2-MA groups than in T2-HA. Energy digestibility did not significantly differ among the groups in either trial. The dietary AH inclusion ratios of 14% in the warm season and 8% to 21% in the cool season appeared to yield optimal ADG, metabolizable energy intake, and economic benefit. Conclusion: Low-level inclusion of AH, ranging from 8% to 21%, is a practical approach for beef cattle feeding. This modified feeding regimen likely will promote increased growth performance during the fattening stage of beef steers in dryland areas of Gansu province, China.

• Journal of Veterinary Clinics
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• v.9 no.2
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• pp.433-449
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• 1992

Total CPK activities and CPK isoenzymes fractions of the sera and tissues were examined to obtain the physiological basic data of ruminant available in veterinary clinical practice. For the sera total CPK activities and CPK isoenzymes fractions, total 39 clinically healthy Korean native goats (3 to 10 months old, IS of female and 18 of male) and 6 of Korean native goats (1 to 2 years old, 3 of female and 3 of male) were used. Seventeen Korean native cattle (3 to 6 years old, 10 of female and 7 of male) and 27 Holstein-Friesian cattle (2 to 8 months old, 7 of female and 3 to 12 years old, 20 of female) were also examined for the sera total CPK activities and CPK isoenzymes fractions. For the total CPK activities and CPK isoenzyme fractions, 3 of female Korean native goats (7 months old), 3 of female Korean native cattle (2 years old) and 3 of dairy cattle (2 years old, 2 of female and 1 of male) were used. The tissues examined were the cerebrum (2 of Korean native cattle), spinal cord (1 of Korean native cattle), heart, lung, diaphragm, reticulum, liver, spleen, kidney, jejunum. colon and femoral muscle. The results obtained were as follows : 1. In Korean native goats less than 1-year-old. serum total CPK activities were 67.8${\pm}$17.7(39.0~96.5) IU/$\ell$ in female and 63.4${\pm}$19.0(28.7~94.4) IU/$\ell$ in male. Further they were 67.0${\pm}$5.3(59.5~70.7) IU/$\ell$ and 54.5${\pm}$11.1(39.1~69.4) IU/$\ell$ in female and male Korean native goats over 1-year-old, respectively. Serum total CPK activities of female were slightly higher than those of male. Significance between age and sex was not found. 2. Serum total CPK activities were 56.8${\pm}$19.7(27.6~90.5) IU/$\ell$ and 65.6${\pm}$10.8(52.8~78.0) IU/$\ell$ in female and male Korean native adult cattle, respectively, Serum total CPK activities of male were slightly higher than those of female, but they were not significant 3. Serum total CPK activities we,e 72.5${\pm}$8.2(57.2~83.2) IU/$\ell$ and 60.8${\pm}$12.5(42.7~80.6) IU/$\ell$ in calves and adult of dairy acttle, respectively. Serum total CPK activities of calves were significantly higher than those of adult(p<0.05). 4. In Korean native goats less than 1-year-old, serum CPK isoenzymes fractions were high with decreasing order of MM>MB>BB and MM>BB>MB in female and male, respectively. Further they were high with decreasing order of MM>MB>BB and MM>B8>MB in female and male Korean native goats over 1-year-old, respectively. The main fractions of CPK isoenzymes were MM in sera of Korean native goats. 5. Serum CPK Isoenzyme fractions were high with decreasing order of MM>MB>BB In both female and male of Korean native cattle. The main fraction among them was MM. 6. Serum CPK isoenzymes fractions were high with decreasing order of MM>BB>MB in both calves and adult of dairy cattle. The main fraction among them was MM. 7. Total CPK activities were high with decreasing order of the femoral muscle>kidney>reticulum>diaphragm>liver>spleen>heart>colon>lung>jejunum in Korean native goats. 8. Total CPK activities were high with decreasing order of the spinal cord >cerebrum>femoral muscle>reticulum>kidney>liver>spleen>diaphragm>lung>colon>heart>jejunum in Korean native cattle. 9. Total CPK activities were high with decreasing order. of the femoral muscle >liver>retoculum>kidney>heart>colon>lung>spleen>jejunum>diaphrasm in dairy cattle. 10. The pattern of the cardiac CPK isoenzymes fractions was identical in Korean native goats, Korean native cattle and dairy cattle. They were high in the order of MM>MB without BB fractions and the main fraction was MM. 11. The pattern of the pulmonary CPK isoenzymes fractions was the same Korean native goats, Korean native cattle and dairy cattle. They were high with decreasing order of MM>MB>BB and the main fraction among them was MM. 12. The pattern of CPK isoenzymes fractions of the diaphragm was Identical in Korean native goats and Korean native cattle. They were high with decreasing order of MM >BB >MB except dairy cattle (MM>MB>BB) but the main fraction among them was MM. 13. The pattern of the reticular CPK isoenzymes fractions was identical in Korean native cattle and dairy cattle. They were high with decreasing order of BB >MM >MB except Korean native goats(BB>MB>MM) but the main, fraction among them was BB 14. The pattern of the hepatic CPK isoenzymrs fractions was identical in Korean native cattle and dairy cattle. They were high with decreasing order of MB >BB >MM except Korean native goats(MB>MM>BB)but the main fraction was MB. 15. The splenic CPK isoenzymes fractions showed different pattern. They were high with decreasing order of MB>BB>MM, MM>BB>MB and BB>MB>MM in Korean native goats, Korean native cattle and dairy cattle, respectively. The main fraction among them was different from each other. 16. The pattern of the renal CPK isoenzymes fractions was identical in Korean native cattle and dairy cattle. They were high with decreasing order of MM >MB>BB except Korean native goats(BB>MB>MM). 17. The CPK isoenzymes fractions of the Jejunums showed different pattern. They were high with decreasing order MM>MB>BB, MM>BB>MB and BB>MM>MB in Korean native goats, Korean native cattle and dairy cattle, respectively. The main fractions were MM In Korean native goats and Korean native cattle, and BB in dairy cattle. 18. The colonic CPK isoenzymes fractions showed different pattern. They were high with decreasing order of MM>MB>BB, MM>BB>MB and BB>rrfB>MM in Korean native goats, Korean native cattle and dairy cattle, respectively. The main fractions were MM in Korean native goats and Korean . native cattle, and BB in dairy cattle. 19. The cerebral CPK isoenzymes fractions were high with decreasing order of BB >MM without MB detected in Korean native cattle and those of spinal cord were high with decreasing order of BB >MM >MB. The main fractions in both cerebrum and spinal cord were BB.