• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1530-1540
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• 2016

This study was conducted to estimate the genetic parameters of ${\beta}$-hydroxybutyrate (BHBA) and acetone concentration in milk by Fourier transform infrared spectroscopy along with test-day milk production traits including fat %, protein % and milk yield based on monthly samples of milk obtained as part of a routine milk recording program in Korea. Additionally, the feasibility of using such data in the official dairy cattle breeding system for selection of cows with low susceptibility of ketosis was evaluated. A total of 57,190 monthly test-day records for parities 1, 2, and 3 of 7,895 cows with pedigree information were collected from April 2012 to August 2014 from herds enrolled in the Korea Animal Improvement Association. Multi-trait random regression models were separately applied to estimate genetic parameters of test-day records for each parity. The model included fixed herd test-day effects, calving age and season effects, and random regressions for additive genetic and permanent environmental effects. Abundance of variation of acetone may provide a more sensitive indication of ketosis than many zero observations in concentration of milk BHBA. Heritabilities of milk BHBA levels ranged from 0.04 to 0.17 with a mean of 0.09 for the interval between 4 and 305 days in milk during three lactations. The average heritabilities for milk acetone concentration were 0.29, 0.29, and 0.22 for parities 1, 2, and 3, respectively. There was no clear genetic association of the concentration of two ketone bodies with three test-day milk production traits, even if some correlations among breeding values of the test-day records in this study were observed. These results suggest that genetic selection for low susceptibility of ketosis in early lactation is possible. Further, it is desirable for the breeding scheme of dairy cattle to include the records of milk acetone rather than the records of milk BHBA.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1262-1270
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• 2008

The objective of this study was to investigate the effect of dietary supplementation with calcium salts of soybean oil fatty acids (CaSO) and linseed oil fatty acids (CaLO) on c9,t11-CLA production in ruminal fluid and milk fat from Holstein dairy cows. Rumen fermentation, lactational performances and fatty acid profiles in ruminal fluid and milk fat were also investigated. Twenty multiparous Holstein dairy cows were allotted randomly into two groups consisting of ten cows in each group according to calving date and average milk yield. The first group of cows was fed a control (without calcium salts) diet and a treatment as 1.0% of CaSO (on DM basis) for 30 days in each period. In the second group, cows were fed the same control diet and 1.0% of CaLO as a treatment in the same manner. The forage: concentrate ratio was 52:48, and diets were formulated to contain 17% crude protein (DM basis) for both groups. Ruminal pH, protozoal numbers and the concentration of total volatile fatty acids were unchanged, however, the ruminal ammonia-N decreased by feeding CaSO or CaLO treatment compared to the control diet. The vaccenic acid (trans-11 C18:1; VA) in rumen fluid increased (p<0.01) by 169% and 153%, and the c9,t11-CLA content of rumen fluid increased (p<0.01) by 214% and 210% in the CaSO and CaLO treatments, respectively, compared to the control diet. In milk fatty acids, the VA content increased by 130% and 132% in the evening and morning milking times, respectively, and the c9,t11-CLA content increased by 125% in both milking times for the CaSO supplementation than that of control diet. In the case of CaLO supplementation, the VA increased by 117% and 114%, and the c9,t11-CLA increased by 96% and 94% in the evening and morning milking times, respectively, compared to the control diet. The contents of VA and c9,t11-CLA of milk fatty acids were numerically higher in the evening milking time compared to the morning milking time for control and both treatments. Finally, these results indicated that the supplementation of CaSO or CaLO treatment increased the VA and the c9,t11-CLA in both ruminal fluid and milk fat of Holstein dairy cows.

• Reproductive and Developmental Biology
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• v.32 no.3
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• pp.199-203
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• 2008

This study was performed to analyze the characterization of plasma hormonal levels during pregnancy in the Hanwoo recipients pregnant by artificial insemination (AI) or somatic cell nuclear transfer (SCNT) embryos. The synchronized recipients pregnant by SCNT embryos produced by Hanwoo fetal fibroblast cells (n=8) and by AI (control, n=5) were used. The plasma hormonal levels were measured by RIA (P4 and E2) and ELISA (cortisol), respectively. In control, the increase of E2 and the decrease of P4 were occurred immediately before the initiation of parturition. The expression pattern of plasma P4 was similar in both groups from 50 to 10 days before parturition, however, it did not decrease even at the expected date of labor in the SCNT recipients. The plasma cortisol was expressed a lower level during pregnancy in the SCNT recipients. But, the cortisol was increased in the cow aborted around 100 days of pregnancy (n=1). Based on these results, it can be postulated that the failure of the hormonal changes immediately before parturition in the SCNT recipients may be one of the most important reasons for a delayed parturition in clone calving.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.223-229
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• 2013

Because colostrum is considered to be the sole source of passively acquired maternal antibodies for calves, newborn calves must consume colostrum to gain disease resistance during their early years of life. Storage of surplus colostrum from dairy cows right after calving and feeding newborn calves in deficiency of colostrum to assure adequate uptake of IgG for protection of the calf has been a common practice in the bovine production. In the current study, 35 colostrums were randomly collected from 3 colostrum banks located in different regions of Korea and monitored for general bacterial contamination and major bovine pathogens. Immunoglobulin concentrations and BVDV-specific antibodies were also determined to evaluate the immune quality of the colostrums. Moderate to severe bacterial contamination (up to 72,000,000 CFU/ml) was observed in most of the colostrums collected from colostrum banks. General immune quality of the colostrums was under the satisfactory level since most of the colostrums contained less than 50 g/L of IgG, which is the minimum concentration for good quality colostrums. Therefore, colostrum for colostrum bank should be collected at the first 2-3 post-partum milkings according to proper harvesting and handling procedures to guarantee the safety and quality of colostrum. In addition, it was recommended that colostrum should be heat-treated before frozen and stored in the bank because pasteurization at $63^{\circ}C$ for 30 min was very effective reducing the risk of disease transmission without causing significant degradation of immunoglobulins.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.7-14
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• 2001

The aims of these study were to diagnose early pregnancy and reproductive disorders by using progesterone concentration and ultrasonography. The measurement of blood progesterone (P$_4$) concentration was conducted to diagnose pregnancy and to detect corpus luteum (CL) or evaluate disorder of CLs. As a result, the incidence rates of reproductive disorders were as follows : SH and EED (41.9%), inacitve ovaries (32.6%), follicullar cyst (9.3%), PCL (7.0%), endometritis (4.7%), pyometra (2.3%) and luteal cyst (2.3%). 61 Cows having P$_4$concentration 1.0 ng/ml(at the insemination) were increased to 1.0 ng/ml $\geq$ 6day after insemination. 50 cows among 61 cows were diagnosed pregnant. 8 cows among 13 HanWoos having P$_4$concentration 1.0 ng/ml at the insemination and 1.0 ng/mnl 6 day after insemination had non-ovulatory estrus and the others had P$_4$concentration 1.0 ng/ml at the insemination and 1.0 ng/ml $\geq$ 6 day after insemination, which was the error of estrus detection. All 13 cows were diagnosed non-pregnant. 47 cows diagnosed pregnant after insemination of P$_4$concentration 3.0 ng/ml were examined by ultrasonography at 30 day post-insemination. As a result, 41 cows were diagnosed pregnant (87.2%) but 14 cows having P$_4$concentration 3.0 ng/ml at 21 day after insemination was diagnosed to non-pregnancy. Calving intervals by surveying 100 cows were as follows 11~12 months (20%), 12~13 months (36%), 13~14 months (19%), 14 months $\geq$ (25%), respectively. In conclusion, hormone and ultrasonography help to detect reproductive disorders exactly and diagnose early pregnancy. This study suggest that diagnosis of early pregnancy and reproductive disorder by blood P$_4$concentration and ultrasonography improve reproduction management of HanWoo.

• Journal of Animal Science and Technology
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• v.55 no.3
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• pp.173-178
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• 2013

The characteristics of lactation persistency was investigated for new evaluation trait using 4,366,900 milk yield records from 436,690 heads of Korean Holstein dairy cattle. The average lactation persistencies of first parity, second parity and over third parity were 97.5%, 95.1% and 94.6%, respectively and there was a trend that after the peak yield, lactation persistency decreased collectively. The average days of peak milk yields after calving was about 50 days, but only 33.2% of cows reached peak yields at 36~66 days (second test day). Also, there was a difference between the milk yield of cows which reached peak yields at first test day by lactation days and that of cows which reached peak yields at second to fourth test day. The estimates of heritabilty and repeatability for mean lactation persistency were 0.16 and 0.35, respectively. The genetic correlation between cumulative lactation persistency from third to tenth test day and that from third to seventh test day was 0.91 and while it increased in later test day, it decreased sharply in earlier test day. The breeding value correlations of Data II and III for Data I were 0.80 and 0.72, respectively, while the rank correlations were 0.78 and 0.71, respectively. Based on the results, the breeding value and rank correlations decreased when more data were added.

• Korean Journal of Veterinary Service
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• v.34 no.4
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• pp.369-378
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• 2011

Incidence of mastitis is highest in dairy cows and it is a leader of all diseases and the economic losses, in dairy farms. The objective of this study is to analyse the incidence of clinical mastitis using the lactation number, lactation month and season of calving. In this study, we used 3,779 lactation data and animal health records collected from 1990 to 2006 at the National Institute of Animal Science. Out of 3,779 cows, a total of 1,721 cows were reported with clinical mastitis, which was 46.3%. The frequency of mastitis increased from 36.9% from first lactation to 56.0% by the fifth lactation. As many as 766 cows (46.9%) showed a recurrence of mastitis after 14 days, apart for two or more and chronic mastitis that were recorded for 657 cows (20.3%). This came to a total of 3,010 cases that had clinical mastitis in the herd for sixteen years. The distribution of incidence of clinical mastitis was highest during the first month of lactation at 24.4%, and it reached to 43.4% by the third month. The incidence of mastitis was even higher for cows in first lactation, showing 28.6% in the first month, and 42.9 percent by third month of lactation. Cows calved during the summer and winter months showed higher rate of incidence with 59.9% and 57.9% within 30 days of lactation, respectively. It is urgently needed to establish a preventative management for heifer cows during their expected first lactation and the clinical specific dry-period management strategies that influence the rate of clinical mastitis during the next lactation. The aim of this study is to present information that might be useful to improve clinical mastitis prevention.

• Journal of the Korean earth science society
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• v.24 no.3
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• pp.216-233
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• 2003

This study delineates the phenomena related with global environmental changes such as global warming, ozone depletion, and El Ni${\tilde{n}}$o/Southern Oscillation (ENSO) noted in the Antarctic. Retreat of ice cliffs, glaciers, and calving of ice shelves indicate the effects of recently aggravated global warming. The ice cliff located at Marian Cove, King George Island, South Shetland Islands off the Antarctic Peninsula has been observed to be retreating faster in the last 7 years than in the previous 38 years since 1956. There are some indications of temperature and precipitation changes associated with ENSO around King Sejong Station. The regression analyses indicate significant trends such as a decrease in the total amount of ozone and an increase in ultraviolet radiation which was seen by a satellite (TOMS-EUV) in September and October which correspond to ozone-hole season over King Sejong Station. Increase of UV radiation due to the ozone depletion in the Antarctic has changed the growth rate of marine organisms. It may also result in changes to the productivity, biomass, and species composition of marine organisms which can affect the whole marine ecosystem. The recent ice-core drilling over Lake Vostok has been reviewed with emphasis on the four cycles of glacial stages over the past 420,000 years. It is time to show more interest in mainland Antarctica through investigations of the coring and vast ice sheet, terrestrial geology, and upper atmospheric sciences in order to understand the past environmental changes and to predict possible changes to the environment in the future.

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.170-175
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• 1988

This experiment was carried out to study the properties of casein micelles obtained from colostral skim milk. As lactation was progressed from parturition until 240h after calving, the content of total protein decreased while the proportion of casein to whey protein increased. Fractionaltion according to the site of casein micelle was done by ultracentrifugation at 100,000 x g for 10 minutes(pellet 1), 30 minutes(pellet 2) and 60 mintes(pellet 3) and the serum casein was prepared by acid precipitation of final supernatant at pH 4.6. During the lactation period, the relative amount of pellet 1(large size) decreased, that of pellet 2(middle size) maintained nearly constant level except for pllet from parturition, that of pellet 3(small size) increased, and the serum casein showed almost constant level. The relative amounts of ${\alpha}_{s1}-casein\;and\;{\alpha}_{s2}-casein\;and\;{\beta}-casein-5P$ in the pellets decreased and that of x-casein increased markedly with decreasing micelle size, but the relative amounts of ${\beta}-casein-1P$(f 29-209), (f 106-209) and (f 108-209) showed little change. The composition of the serum casein was different from that of the skim milk casein.

• Journal of Animal Science and Technology
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• v.46 no.2
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• pp.137-144
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• 2004

Algorithms for estimating breeding values on several categorical data by using latent variables with threshold conception were developed and showed. Thresholds on each categorical trait were estimated by Newton’s method via gradients and Hessian matrix. This algorithm was developed by way of expansion of bivariate analysis provided by Quaas(2001). Breeding values on latent variables of categorical traits and observations on linear traits were estimated by preconditioned conjugate gradient(PCG) method, which was known having a property of fast convergence. Example was shown by simulated data with two linear traits and a categorical trait with four categories(CE=calving ease) and a dichotomous trait(SB=Still Birth) in threshold animal mixed model(TAMM). Breeding value estimates in TAMM were compared to those in linear animal mixed model (LAMM). As results, correlation estimates of breeding values to parameters were 0.91${\sim}$0.92 on CE and 0.87${\sim}$0.89 on SB in TAMM and 0.72~0.84 on CE and 0.59~0.70 on SB in LAMM. As conclusion, PCG method for estimating breeding values on several categorical traits with linear traits were feasible in TAMM.