• Journal of Embryo Transfer
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• v.19 no.3
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• pp.209-218
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• 2004

To investigate the feasibility of embryo transfer technology to promote productivity of cattle, 36 cows(18 Holstein, 18 Hanwoo) were superovulated. Fresh embryos were transferred to 25 recipients(14 Holstein, 11 Hanwoo), whereas frozen embryos were transferred to 17 recipients(10 Holstein, 7 Hanwoo). Two embryos were transferred at a time to 13 recipients(9 Holstein, 4 Hanwoo) to produce twin calves. 1. 75.0％ of donor cattle were reacted to hormonal treatment far superovulation. 2. The rate of embryo recovery by non-surgical method for Holstein and Hanwoo was 90.4 and 95.8％ in comparison with numbers of corpus luteum. 3. Of all the ova collected non-surgically, the rate of viable blastocyst was 66.4％ and the rate of transferrable blastocysts was 48.6％. 4. The rate of embryo collection by one-catheter method was 75.0％. 5. The rate of pregnancy/delivery following embryo transfer with fresh embryos was 60.0％. 6. The rate of pregnancy/delivery following embryo transfer with frozen embryos was 35.3％. 7. In embryo transfer to produce twin calves, the rate of pregnancy/delivery was 28.6％ with fresh embryos and 16.7％ with frozen embryos.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.173-182
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• 2016

This study was aimed to identify the phenotypic relationships between calving interval and lactation curve parameters in Korean Holstein cow. The data of 36,505 lactation records was obtained from the Dairy Herd Improvement program run by Dairy Cattle Improvemnet Center of National Agricultural Federation of Korea. All lactation records were collectied from the multiparous cows calving between 2011 to 2013. The estimated lactation curves were drawn using Wood model based on actual milk yield records, and NLIN Procedure of SAS program (ver. 9.2). General linear multivariate models for calving interval, 305-d milk yield, lactation parameters(A, b, c), persistency, peak day, and peak yield included fixed effects of calving year-season (spring, summer, fall and winter) and parity(2, 3 and 4). For calving interval, 305-d milk yield, lactation parameters(A, b, c), persistency, peak day and peak yield, all two fixed effect(calving year-season, parity) were significant(p<0.05). The estimated lactation functions using Wood model for 2, 3, and 4 parity were yt=24.66t0.175e-0.00302t, yt=24.69t0.192e-0.00334t, and yt=24.22t0.200e-0.00341t, respectively. Phenotypic correlation (partial residual correlation) between calving interval and 305-d milk yield, A, b, c, persistency, peak day, and peak yield were 0.093, -0.014, 0.028, -0.046, 0.099, 0.085, and 0.052, respectively. To conclude, if calving interval increase then ascent to peak, persistency, peak day and peak yield are increase, and descent after peak is decrease. So, total 305-d milk yield is increase.

• Journal of Practical Agriculture & Fisheries Research
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• v.8 no.1
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• pp.43-51
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• 2006

An experiment was conducted to examine how the response of dairy cows to a change from twice to thrice-daily milking is affected by deficiencies in the dietary supplies of three amino acids, His, Met and Lys. The amino acid deficiencies were obtained by feeding the cows a diet of grass silage and a cereal-based supplement containing feather meal as the sole protein supplement. Taken overall, the results show that when cows were given the feather meal diet, even though dietary ME was in considerable excess, a deficiency of specific amino acids prevented any increase in milk yield in response to increasing the frequency of milking from twice to thrice daily. The results of half-udder milking showed that when cows consumed the diet deficient in amino acids, milking one half of the gland more frequently reduced the secretion of protein and lactose by the control gland. Neither MBF nor the ratio of 3-MH/creatinine in urine was affected by thrice-daily milking. The present results go a stage further in showing that, against a background of insufficient dietary amino acids, the stimulus of thrice-daily milking is not sufficient to induce a measurable change in the partition of amino acid use between body and udder.

• Journal of Embryo Transfer
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• v.20 no.3
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• pp.233-238
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• 2005

This study was carried out to investigate effects of claw trimming on reproductive efficiency in lactating cow. The results obtained were summarized as follows: 1. Days to 1st postpartum service were 180.9$\pm$47.2 days for control and 111.9$\pm$17.1 days for claw trimming. 2. Conception rate by 1st postpartum service was $25.0\%$ for control and $66.7\%$ for claw trimming. 3. Days to 1st postpartum conception were 258.1$\pm$43.3 days for control and 151.6$\pm$26.2 days for claw trimming(p<0.05). 4. Services per conception were 1.88$\pm$0.23 times for control and 1.44$\pm$0.18 times for claw trimming. 5. Calving interval was 489.3$\pm$47.2 days for control and 430.8$\pm$26.2 days for claw trimming.

• Journal of agriculture & life science
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• v.46 no.1
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• pp.113-121
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• 2012

A total of 150,624 records of Holstein milk production collected from 2005 to 2009 were analyzed to investigate the effects of two different contemporary group definitions, parity and somatic cell score (SCS). The first definition (H BY S) of contemporary group was milking cows and heifers born in the same year and season. And the second thing (H CY S) was milking cow and heifers that delivered calves in the same year and season. Effects of contemporary group, parity and regression effect on SCS from two models were highly significant sources of variation. Coverage of variation ($R^2$) was somewhat higher in models with H BY S as contemporary group. From multivariate models with H BY S, phenotypic correlation coefficients of milk components were estimated high and positive. However, the phenotypic correlation coefficient between milk yield and SCS was -0.09, which was low enough to evidence no correlation between them. Phenotypic correlation between SCS and butter fat or between SCS and protein were also negligible but negative. From multivariate models with H CY S as contemporary group, phenotypic correlation among milk traits and SCS were similar to the estimates from models with H BY S. However, SCS in these models were lowly but negatively correlated with milk yield, milk protein, butter fat or SNF, and the phenotypic correlation coefficients of which were -0.10, -0.08, -0.08, -0.11, respectively.

• Journal of Veterinary Clinics
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• v.19 no.2
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• pp.228-235
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• 2002

Mastitis is the most costly disease results in lost milk production, decreased milk quality, milk discard, early culling of cows, drug costs and labor costs in dairy cow. Until now, a antibiotic administration at the end of lactation, dry cow therapy has been known the most effective and widely used mastitis control method. However, dry cow therapy do not control a new infection in the late dry and prepartum period because dry cow products have only persistent activity in the early dry period. Therefore, this study was conducted to evaluate clinical effect of sustained released biodegradable cephalexin microsphere using PLGA in bovine mastitis control during dry period. PLGA has been approved as controlled drug release system because of non-toxic, non-tissue reactive and bioerodible characteristics. This study revealed that cephalexin microsphere had a spherical shape with characteristic porous structure on the surface. Also, in vitro drug release studies are clearly observed that the release rate of cephalexin from PLGA microsphere decrease during the first 21 days after initial burst and then increase again between 3 and 4 weeks showing pulsatile releasing pattern. On the other hand, as tried in field the new infection rate, cure rate and mean SCC after parturition in cephalexin microsphere infused group were significantly differenced as compared to the control group. Accordingly, a sustained release of cephalexin from a biodegradable microsphere could make dry cow therapy more efficiently by preventing a new infection and decreasing the number of existing infection of mammary gland during dry period.

• Journal of Veterinary Clinics
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• v.28 no.2
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• pp.267-270
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• 2011

Ovarian tumors in cows are uncommon and most are granulosa cell tumors. Bovine ovarian fibromas are extremely rare and tend to occur in older animals. This paper reports the case of a large ovarian mass found in a primiparous dairy cow which had shown no sign of cycling after calving. The mass continued to increase in size as detected during six-month serial observations by ultrasonography. An ovariectomy was subsequently performed and the growth was diagnosed as an ovarian fibroma by gross and microscopic examination. This case is the first report of an ovarian fibroma observed in a living dairy cow.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.839-846
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• 2006

This study was conducted to evaluate the effects of dietary addition of sucrose, propylene glycol and Tween 80 (Polysorbate 80 : Non-ionic Surfactants) on pre-partum (21 d) and post-partum (21 d) nutrients intake, blood metabolites, occurrence of metabolic disorders, milk yield and its composition in Holstein cows. Two basal diets were formulated each for pre- and post-partum period. The diets were mixed daily and fed at ad libitum to transitional cows. Forty cows of similar parity and milk yield were randomly divided into four groups (ten animals in each). The cows in three groups were supplemented either with 280g of sucrose/day (SU), SU+64g propylene glycol/day (SUP) or SUP+50g Tween80/day (SUPT). The feed for the fourth group was not supplemented and this group served as control (C). Pre-partum DM, total digestible nutrients (TDN), and crude protein (CP) intake was similar in cows fed C, SU, SUP, and SUPT diets. Post-partum DM, TDN, and CP intakes were the highest with SUPT diet followed by SU, SUP and control diets. Pre-partum blood non-esterified fatty acids (NEFA) concentration was noticed significantly higher in cows fed control diet compared to those fed SU, SUP and SUPT diets. The concentration of NEFA was similar at calving and during post-partum period across cows fed different experimental diets. Blood glucose and Ca concentration during pre- and post-partum periods were not significantly different in cows fed C, SU, SUP and SUPT diets. Milk yield (kg/day) was similar in cows fed different experimental diets. However, milk fat percent and 4% fat corrected milk yield were higher in cows fed SU diet (p<0.05) followed by SUP, SUPT and C diets. One case of ketosis was recorded in cows fed control diet however its occurrence was not observed in cows fed other diets. Occurrence of retained placenta and mastitis was numerically higher in cows fed control diet compared with those fed SU, SUP and SUPT diets. In conclusion, the NIS and propylene glycol feeding along with sucrose could improve the 4% fat corrected milk and fat yield in early lactating cows with significant reduction in NEFA and metabolic disorders during transitional period.

• Journal of Embryo Transfer
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• v.20 no.2
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• pp.79-87
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• 2005

The ovaries from Hanwoo and Holstein were collected from labattoir and transferred to laboratory. Oocytes were aspirated and incubated in $CO_2$ incubator for 24 hours for maturation. Oocytes were coincubated with the sperms for 5 hours. Cleaved oocytes were selected 48 hours after coincubation and half of the medium was changed newly every 48 hour until blastocyst formation. Cleavage rate and blastocyst rate were investigated according to different breeds and different status of cumulus cells surrounding the oocytes. Blastocysts were either transferred to the recipients or frozen until use. The result of embryo transfer with fresh or frozen embryos was investigated. The rate of male offspring following embryo transfer was also investigated. The rate of cleavage was $66.4\%$ for Hanwoo and $62.4\%$ for Holstein oocytes. The rate of cleavage according to status of oocyte was shown highest in the oocytes completely surrounded with cumulus cells and lowest in denuded oocytes for both Hanwoo and Holstein oocytes. The rate of blastocyst from cleaved oocytes was $40.6\%$ for Hanwoo and $36.9\%$ for Holstein. The rate of pregnancy/delivery following embryo transfer with fresh IVF embryos was $57.2\%$ for Hanwoo and $53.3\%$ for Holstein. The rate of pregnancy/delivery following embryo transfer with frozen IVF embryos was $40.9\%$ for Hanwoo and $36.4\%$ for Holstein. The rate of male calf produced by embryo transfer was $63.6\%$ for Hanwoo and $50.0\%$ for Holstein.

• Journal of Veterinary Clinics
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• v.10 no.2
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• pp.163-169
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• 1993

This study examined the incidence of disease and blood biochemical values in 68 Holstein cattle during the a month period after parturition. In order to compare the blood biochemical values, the animals were divided into 2 groups of prepartum and 4 groups of postpartum according to the blood collecting day, respectively. The results compared postpartum with prepartum were obtained as follows : the incidences of displacement of abomasum, culled and retained placenta were 11.8%. 13.2% and 8.8%, respectively. In the normal group(pre and post parturition group), NEFA and bilirubin were increased. Triglyceride and cholesterol were significantly lower than In the pre-parturition group, and total lipid was decreased. In the disease group, displacement of abomasum was significantly higher than in the normal group in the levels of NEFA, triglyceride and bilirubin. Culled was significantly higher than in the normal group in the levels of NEFA, AST and bilirubin. but lower than in the normal group in the levels of triglyceride and cholesterol. Retained placenta was significantly higher than in the normal group in the levels of NEFA and bilirubin, but lower than in the normal group in the levels of triglyceride.