• 한국동물위생학회지
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• 제24권1호
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• pp.89-94
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• 2001

In order to investigate the relationship between milk hygienic quality and some environmental factors such as the herd size and types of milking machines, we sampled and examined the level of total bacterial count, coliforms, Staphyococcus aureus, somatic cell counts(SCC) and fat rates in raw milk. of the 84 dairy farms, the prevalence of level on number of standard plate count over 100,000cfu/$m\ell$ and coliforms over 1,000cfu/$m\ell$ in bulk milk were 25.0% and 15.6%, respectively. Also, 2 farms(2.4%) were exceed the level on number of 500cfu/$m\ell$ S aureus in raw milk. The prevalence of dairy herd with first grade of total bacterial count(TBC) according to bucket, pipe line and parlour milking system was 40.0%, 74.0% and 84.0%, respectively. The prevalence of dairy herd with first grade of TBC according to grade 1, 2 and 3 by SCC was 77.8%, 83.2%. and 69.2%, respectively. Therefore, the relationships between hygienic quality in raw milk and the herd size, types of milking machines, were significant. In conclusion, this study could be overemphasized the importance of herd management condition for milk hygienic qualify.

• Applied Biological Chemistry
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• 제36권6호
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• pp.416-423
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• 1993

건조방법 및 원료성분을 달리하여 분유를 제조하고 이들분유의 몇 가지 리올로지 특성을 Instron Universal Testing Machine으로 측정하여 얻어진 결과는 다음과 같다. 드럼건조된 전지분유의 부피밀도는 $0.382\;g/cm^3$으로 탈지 및 조제 분유보다 높았고, 분무 건조된 탈지 분유의 Hausner ratio, 평정각 및 compressibility 는 각각 1.127, $32.5^{\circ}$, 0.029로 탈지 분유는 자유롭게 흐르는 것을 보여주었으며, 드럼건조된 전지분유의 compressibility는 수분 함량이 4.96%에서 3.89%로 감소함에 따라 0.079에서 0.052로 낮아졌다. 전지분유 그래뉼의 compressibility는 0.056으로서 분유의 compressibility보다 낮았다. 분무 건조된 분유는 구형으로서, 동결건조나 드럼건조된 분유보다 더 견고함을 나타냈다.

• 한국식품위생안전성학회지
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• 제2권3호
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• pp.109-119
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• 1987

본 연구는 유질향상을 위한 기초자료를 제공하고자 1986년 5월부터 1987년 4월 까지 경기도 일부지역의 234개 목장을 대상으로 목장별 집합원유에 대해 유지방검사, 세균수시험 (MBRT), 체세포수시험을 실시하여 유질을 평가하였고, 목장의 낙농위생관리실태를 조사하여 유질과의 관련성을 분석한 결과 다음과 같은 결론을 얻었다. 1. 유지방율검사, 평균 유지방율은 3.56%였고, 월별로는 1월 3.67%, 4월 3.64%, 7월 3.43%, 10월 3.48%였으며, 월별 유지방율의 차이는 총계학적으로 유의성이 인정되었다(p<0.005). 2. 세균수시험 (MBRT) 결과, 집합원유의 세균수가 200만/ ml 이하인 I급 목장이 평균 132개(56.4%)였고, 월별로는 1월 153개(65.4%), 4월 150개(64.1%), 7월 76개(32.5%), 10월 141개(60.2%)였으며, 월별 MBRT등급의 차이는 총계학적으로 유의성이 인정되었다(p<0.005). 또한 납유량이 많은 목장구가 적은 목장구보다, 냉각기를 보유하고 있는 목장구가 보유하지 않은 목장구보다, 탱크집유목장구가 통집유목장구보다, 집합원유 MBRT I 등급의 비율이 더 높았으며, 납유량이 다소 (p<0.05), 냉각기 보유여부(p<0.01), 집유수단(p<0.05) 등과 MBRT 등급간에는 유의한 관련성이 인정되었다. 3. 체세포수시험 결과, 집합원유 체세포수가 50만 cells/ ml 이하인 I급 평균 223개(95.3%)였고, 월별로는 1월이 227개(97.0%), 4월 222개(94.9%), 7월 218개(93.2%), 10월 223개(95.3%)였으며, 월별 체세포수 등급의 차이는 유의성이 인정 되지 않았다. 한편, 착유후 유두침지소독 및 건유기유방염 치료를 병행실시한 목장구가 이의 단일실시 목장구보다, 유방세척용수건을 개체별로 사용한 목장구가 여러개체에 공동으로 사용한 목장구보다 체세포수가 더 낮았으며, 착유후 유두침지소독 및 건유기유방염 치료여부(p<0.01), 유방세척용 수건사용방법(p<0.01) 등과 체세포수간에는 유의한 관련성이 인정되었다.

• Journal of Dairy Science and Biotechnology
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• 제32권2호
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• pp.63-70
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• 2014

Automatic milking systems (AMS) have been increasingly introduced to Korean dairy farms. However, in comparison with conventional milking systems (CMS), some negative changes in milk quality are being observed. The use of AMS leads to an increase in milking frequency, which in turn might result in higher physical stress on the milk, possibly causing changes in the milk fat globule (MFG) membrane. Therefore, the purpose of this study was to examine the effect of the different milking systems on the milk quality, with a focus on milk fat properties. At the same time, we studied the effect of feeding the dairy cows with protected fat. Raw milk samples were taken monthly from individual cows as well as from bulk tanks at four AMS and four CMS dairy farms. We measured quality-related parameters such as MFG size distribution, free fatty acid content and composition, and acid values. Although most results showed no significant differences with regard to the milking system, we found a relatively high positive correlation between MFG size and milk fat content. Moreover, larger MFG size was observed in the milk when cows had been fed protected fat. The significantly higher (P< 0.05) free fatty acid content of milk observed under this experimental condition could be attributed to higher milking frequency as a result of using AMS.

• Journal of Animal Science and Technology
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• 제64권3호
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• pp.531-538
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• 2022

In Italy, buffalo mozzarella is a largely sold and consumed dairy product. The fraudulent adulteration of buffalo milk with cheaper and more available milk of other species is very frequent. In the present study, Fourier transform infrared spectroscopy (FTIR), in combination with multivariate analysis by partial least square (PLS) regression, was applied to quantitatively detect the adulteration of buffalo milk with cow milk by using a fully automatic equipment dedicated to the routine analysis of the milk composition. To enhance the heterogeneity, cow and buffalo bulk milk was collected for a period of over three years from different dairy farms. A total of 119 samples were used for the analysis to generate 17 different concentrations of buffalo-cow milk mixtures. This procedure was used to enhance variability and to properly randomize the trials. The obtained calibration model showed an R² ≥ 0.99 (R² cal. = 0.99861; root mean square error of cross-validation [RMSEC] = 2.04; R² val. = 0.99803; root mean square error of prediction [RMSEP] = 2.84; root mean square error of cross-validation [RMSECV] = 2.44) suggesting that this method could be successfully applied in the routine analysis of buffalo milk composition, providing rapid screening for possible adulteration with cow's milk at no additional cost.

• 대한수의학회지
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• 제40권3호
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• pp.645-652
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• 2000

This study was performed to investigate Mycoplasma (M) spp. infection status of dairy cow in South Korea. Among 8,485 bulk tank milk collected from dairy farms of the 5 areas, 26 samples (0.30%) were positive for Mycoplasma by direct culture method. The isolation rates of Mycoplasma spp. according to the areas were 0.51% in Kyonggi, 0.16% in Cholla, 0.23% in Gyoungsang, 0.12% in Chungchong, and 0.08% in Kangwon. In the species identification test by indirect immunoperoxidase test, 16 out of 26 isolates were identified as M bovis (61.53%), M bovigenitalium (23.07%), M californicum (7.69%), M alkalescens and Acholeplasma laidlawii (3.84%), respectively. The isolation rate of Mycoplasma spp. from 208 quarter milk samples in culling cows due to severe clinical mastitis was 3.0%. These Mycoplasma spp. were identified as M bovis (62.0%), M bovigenitalium (12.0%), M californicaum (12.0%), and M alkalescens (12.0%). This study shows that the bovine mammary gland infected by Mycoplasma spp. is present in some dairy farms and the routine culture test of bulk tank milk samples for Mycoplasma is needed for a high quality milk promotion services.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1683-1689
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• 2001

The levels of urea nitrogen both in blood (BUN) and milk (MUN), and milk protein (MP) reflect protein and energy intake in dairy herd feeding. Blood and milk constituents may be changes rhythmically and influence by different sampling time within a day and after feeding. Trials were conducted using five dietary treatments in both lactating and dry cows to study the effects of sampling time on concentrations of BUN, MUN and whole blood ammonia nitrogen (BAN) in practical dairy cow feeding in Taiwan. The conventional feed ingredients and forages including corn silage, alfalfa hay, timothy or pangola hay and corn grain were used as major source of the diet to follow practical dairy cow feeding. Five different diets were varying in amounts (low=L; standard=S; high=H) of crude protein (P) and energy (E) according to the NRC (1989). The energy to protein ratios in kcal/kg for the PSES, PLES, PHES, PSEH and PSEL were 10.82, 12.54, 9.41, 12.53 and 9.13 in lactating cows, and 11.38, 13.33, 9.78, 13.28 and 9.74 in dry cows, respectively. Results showed that after feeding at 9:30, BUN reached peak at 13:30 and was significantly higher than those to that sampled at 14:30 to 18:30 (p<0.05) in dry cows. Therefore the best blood sampling time for urea nitrogen assay in dry cows is 4 hours after morning feeding. In lactating cows, BUN of 13:30 was significantly higher than those of 8:30 to 11:30 (p<0.05), but there were no significant difference between the BUN values of other sampling time. Hence the suitable blood sampling time for BUN value in lactating cows was located on 3 to 8 hours after morning feeding, but the best time was 4 hours after morning feeding. MUN content is significantly higher in the afternoon collected bulk milk than the fore-strip morning milk (p<0.05), therefore the best sampling time for MUN is from afternoon collected bulk milk. Diurnal BAN changed without traceable rhythmic pattern and was negatively correlated to the BUN (r = -0.78). It is suggested that BAN may not be a good indicator for monitoring dairy cow feeding.

• 한국가축번식학회지
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• 제21권2호
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• pp.191-195
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• 1997

The objective of this study were to compare two methods of analysis of milk urea nitrogen (MUN) and to relate conentration of MUN to pregnancy rate in dairy cows. The Azotest and Sigma method for MUN analysis were compared. The Azotest consistently underestimated the Sigma values for same samples, except for those in rank 3. The CV for the Azotest, within each rank, were less than 15%, demonstrating acceptable repeatability of the Azotest within a rank. Concentrations of MUN higher or lower than MUN in rank 3 and 4 were associated with decreased pregnancy rate. Mun concentrations in rank 5 and 6 were associated with a, pp.oximately a 16 percentage point decrease in pregnancy rate. Mun concentrations in rank 5 and 6 were associated with a, pp.oximately a 16 percentage point decrease in pregnancy rate after AI in dairy cow. This results suggest that Azotest may be benificial to dairy producers to monitor urea nitrogen concentration in their herd in efforts to maintain or improve reproductive efficiency.

• 한국동물위생학회지
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• 제45권1호
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• pp.39-45
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• 2022

The total bacteria count is significantly important factor for hygienic quality in raw milk. BactoScan FM^TM and BactoCount IBC^TM are the automated instruments for the determination of the total bacterial count in raw milk. They have been used after calibration by standard plate count (SPC) method in South Korea since 2000. It is necessary to re-evaluate for total bacterial counter according to the improvement of milk quality and the change of milk quality grade. Therefore, this study was evaluated the conversion mode of the two machines by SPC method. We collected 921 bulk-tank milk samples throughout the concentration range of 1,000~1,000,000 CFU/mL from June 2020 to October 2021. As a result, when compared by the SPC value, there was a slight difference in total bacterial count in BactoScan below 10,000 CFU/mL and above 200,000 CFU/mL and in BactoCount above 100,000 CFU/mL, respectively. Therefore, the conversion factor for BactoScan and the conversion equation for BactoCount were newly adjusted based on SPC value, and then the correlation coefficients (R²) was 0.85 or higher. In addition, the correlation (R²) between BactoScan and BactoCount was 0.91, which means the results were high positive correlation. These results are expected to contribute to improving the accuracy of the automated instruments for determining of total bacterial count in raw milk.

• 한국동물위생학회지
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• 제36권1호
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• pp.7-13
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• 2013

Bovine viral diarrhea virus (BVDV) is one of the most important disease viruses in cattle that can cause severe economical losses due to decreased fertility, abortion, diarrhea, and respiratory symptoms. Therefore, this study was aimed to investigate prevalence of BVDV infection (Transiently infection, Persistently infection) in dairy cattle in Gyeongnam southern area, Korea and use this data as the basis for establishing an eradication program and policy. A total of 44 bulk-tank milk samples (farms) collected in milk collecting center were tested for BVDV antibody using an ELISA. As the result, out of a total of 44 bulk-tank milk samples (farms), 38 (86.4%) samples were BVDV antibody positive. Blood samples (17 farms, n=543) were collected from BVDV antibody positive farms in bulk-tank milk, tested for BVDV antigen with ELISA and PCR. BVDV infected farms were 47% (8/17) and BVDV infected head were 2.2% (12/543). Persistently infected cattle (PI) were detected at 6 (35.3%) farms out of 17 farms and a total of 6 (1.1%) out of 543 head of cattle were identified as PI. The seropositive of BVDV antibody at farms and head were 100% (17/17) and 49.45% (91/184), respectively. The seroprevalence of BVDV antibody in PI infected farms (67.35%) much higher than that of BVDV antibody in transiently infected cattle (TI) infected farms (45%) and uninfected farms (34.48%). For eradication of BVDV infection in cattle populations, First of all, we should remove PI and need vaccination.