• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.295-300
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• 1987

This experiment was carried out to review the chemical composition and microbiological aspects of seasonal raw milk collected from the dairy plants in Kangwon, Kyunggi, Seoul, Chungbuk, Chungnam, Jeorbuk, Jeonnam, Kyungbuk and Kyungnam of Korea. The results were summarized as follows: 1. The average composition of raw milk produced during spring season in each area showed moisture 88.00%, protein 3.49%, fat 3.43%, lactose 4.37%, and ash 0.75% but in summer it showed moisture 88.30%. protein 3.28%, fat 3.32%, lactose 4.26%, and ash 0.70%. 2. The microbiological aspects of raw milk in spring season showed viable bacteria counts $3.7{\times}10^6$, coliforms $2.2{\times}10^5$, thermoduric bacteria $1.4{\times}10^5$, thermophiles $1.4{\times}10^5$, psyclrotrophic bacteria $8.2{\times}10^5$, mould and yeast $1.9{\times}10^4$ per milliliter but in summer it showed viable bactteria counts $3.7{\times}10^6$, coliforms $2.3{\times}10^5$, thermoduric bacteria $2.3{\times}10^5$, thermophiles $7.5{\times}10$, psychrotrophic bacteria $5.0{\times}10^5$, mould and yeast $1.3{\times}10^4$ per milliliter.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.218-225
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• 2005

This study was performed to determine sequence variation and RFLP of the mt DNA D-loop region using Southern blot hybridization analysis and to develop mt DNA marker affecting milk production traits in Hanwoo cows. The PCR was used to amplify an 1142 bp fragment within the D-loop region of mt DNA using specific primers. Mt DNA were digested with seven restriction enzymes and hybridized using DIG-labeled D-loop probe. The mt DNA RFLP polymorphisms were observed in the four enzymes, BamHI, RsaI, XbaI and HpaII. Nucleotide substitutions were detected at positions 441 (G/C), 469 (T/C), 503 (C/T), 569 (G/A), 614 (C/A) and 644 (C/T) of the mt DNA D-loop region between two selected lines. Significant relationship between the XbaI RFLP type and breeding value was found(p<0.05). Cows with A type had higher estimated breeding values than those with B type (P<0.05) between high and low milk production lines. Therefore, the RFLP marker of mt DNA could be used as a selection assisted tool for individuals with high milk producing ability in Hanwoo.

• Korean Journal of Food Science and Technology
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• v.46 no.2
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• pp.165-172
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• 2014

Mixed fermentation of cow milk was performed by sequential co-cultures with Bacillus subtilis and Lactococcus lactis. After a first fermentation step with B. subtilis for 6 h, the number of viable cells increased to $2.5{\times}10^8$ CFU/mL. The second fermentation step with L. lactis resulted in increased viable cells $1.09{\times}10^{10}$ CFU/mL for 3 days and increased acidity. However, the number of viable B. subtilis cells was decreased greatly to $5{\times}10^1$ CFU/mL following fermentation with L. lactis. Milk proteins were markedly hydrolyzed by the first fermentation after 2 h, and the second fermentation induced curd formation in milk. However, after 4 h, the first fermentation resulted in higher whey separation and 80 mg% tyrosine content. Gamma-aminobutyric acid (GABA) production was dependent upon the degree of protein hydrolysis by first fermentation. Second fermentation resulted in 0.14% GABA. The milk fermented by B. subtilis indicated the rough surface of yogurt depended upon the degree of protein hydrolysis. In conclusion, set-type yogurt was efficiently produced by co-culturing of milk, and fortifying with peptides, GABA, and probiotics.

• Journal of Veterinary Clinics
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• v.19 no.4
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• pp.391-396
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• 2002

cows, in order to suggest a means for the improvement of milk production. A total of 30 Holstein cows (3rd to 5th of parity) were used and assigned to two groups according This study investigated blood biochemical values between high and low yielding dairy to milk production levels at 15, 30, 60 and 90 days postpartum. Milk production of group A was less than an average of 27 kg/day and that of group B was an average of 30 kg/day. Blood samples were collected by jugular venipuncture from each cow six times at 15 days before the anticipated calving date, within 12 hours postpartum (0 days) and at 15, 30, 60 and 90 days after calving. In serum mineral concentrations, group B was consistently higher than group A in both Mg and Ca. Inorganic phosphorus concentrations showed a little fluctuation between the groups at antepartum and at postpartum, but group B was significantly higher than group A at 15 and 30 days after calving (p < 0.05). In serum biochemical values cholesterol concentrations were consistently higher in group B except at 0 days. BUN and glucose concentrations did not differ between the groups. The concentration of vitamin A of group B was significantly higher than group A at 15 days before the anticipated calving date and at 15 days postpartum (p < 0.01), but at 30, 60 and 90 days postpartum vitamin A concentration of both groups were similar. Vitamin E concentration did not differ between the groups during the experimental period. Results of this study suggest that raising the levels of Mg, Ca, Pi and vitamin A in serum would be effective in increasing milk production of low producing cows.

• Journal of Veterinary Clinics
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• v.35 no.6
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• pp.258-265
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• 2018

We aimed to identify the relationships between puerperal metritis (PM) and serum metabolites, uterine health, milk yield, and reproductive performance in dairy cows. Blood samples from 150 Holstein dairy cows were collected just after calving, and at 1, 2, and 4 weeks postpartum to measure serum concentrations of ${\beta}$-hydroxybutyrate (BHBA), urea nitrogen, total cholesterol (TCH), albumin, aspartate aminotransferase (AST), calcium, and magnesium. PM was diagnosed by the presence of fever (${\geq}39.5^{\circ}C$) and a watery, fetid uterine discharge during the first 14 days after calving. Cows were divided into two groups on the basis of the presence or absence of the disease: a control group (n = 83) and a PM group (n = 67). The cows diagnosed with PM were subcutaneously administered with 2.2 mg/kg ceftiofur for 3-5 days. The serum concentrations of BHBA tended to be higher (P = 0.06) and AST was higher (P < 0.05) in the PM group than in the control group 1 week after calving, whereas serum concentrations of urea nitrogen, TCH, albumin, calcium, and magnesium were lower (P < 0.05-0.0001) after calving in the PM group than in the control group. The probability of clinical endometritis was higher (odds ratio = 5.40, P < 0.001) in the PM group than in the control group. Moreover, the proportion of neutrophils in the uterus was also higher in the PM group than in the control group 4, 6, and 8 weeks after calving (P < 0.001). The mean milk yield 1 and 2 months after calving was lower (P = 0.05) in the PM group than in the control group. The hazard of pregnancy by 180 days after calving tended to be lower (hazard ratio = 0.60, P = 0.07) in the PM group than in the control group, which led to an extended mean interval between calving and pregnancy (19 days) in the PM group (P < 0.01). In conclusion, PM is associated with higher postpartum concentrations of BHBA and AST, and lower concentrations of urea nitrogen, TCH, albumin, calcium, and magnesium. Moreover, PM is associated with subsequent poor uterine health, lower milk yield, and poorer reproductive performance in dairy cows.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.4
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• pp.343-348
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• 2018

In this study, the effect of daily short-distance walking exercise on milk production and metabolic status of the lactating dairy cows was investigated. The experiment was conducted with 10 lactating dairy cows comprising 2 groups (5 dairy cows/group), which were walking activity and non-walking activity. The walking activity (WA) group lactating dairy cows walked outdoors for 1 km/d, and the non-walking activity (non-WA) lactating dairy cows were maintained within a cowshed from $18^{th}$ April to $30^{th}$ May. The activity volume of the neck was not significantly different between the groups, but the activity volume of the leg was higher in WA group compared with non-WA (p<0.05). The rectal temperature was higher in the WA group ($38.6^{\circ}C$) compared with non-WA ($38.2^{\circ}C$) (p<0.05). No significant differences in dietary NE intake, milk production and milk composition were found between the groups. The plasma cortisol concentration was higher in WA group ($2.14{\mu}g/dl$) compared to non-WA ($0.95{\mu}g/dl$) (p<0.05). However, plasma cortisol level of WA dairy cows was significantly decreased as compared with non-WA cows. On the contrary, the level of plasma melatonin was increased in WA cows than that of non-WA dairy cows. It may be interpreted as a change in physical fitness. From this study, we suggest that walking activity can be improved energy balance. Further investigation is needed to determine whether different combinations of distance, rate or doing in morning or afternoon will stimulate energy balance.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.375-386
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• 2019

Objective: We hypothesized that silage additives may alter the undigested neutral detergent fiber (uNDF) content through ensiling. Therefore, urea and formic acid were applied to corn, whole barley crop (WBC) and alfalfa to change uNDF content of the ensiled forages. Methods: Six experimental diets at two groups of high uNDF (untreated corn and alfalfa silages [CSAS] and untreated whole barley and alfalfa silages [BSAS]) and low uNDF (urea-treated corn silage+untreated alfalfa silage [$CS_UAS$], urea-treated whole barley silage+untreated alfalfa silage [$BS_UAS$], untreated corn silage+formic acid-treated alfalfa silage [$CSAS_F$], and untreated whole barley silage+formic acid-treated alfalfa silage [$BSAS_F$]), were allocated to thirty-six multiparous lactating Holstein dairy cows. Results: The untreated silages were higher in uNDF than additive treated silages, but the uNDF concentrations among silages were variable (corn silage0.05). Milk yield tended to increase in the cows fed high uNDF diets than those fed low uNDF (p = 0.10). The cows fed diet based on urea-treated corn silage had higher milk yield than those fed other silages (p = 0.05). The substitution of corn silage with the WBC silage tended to decrease milk production (p = 0.07). Changing the physical source of NDF supply and the uNDF content from the corn silage to the WBC silage caused a significant increase in ruminal $NH_3-N$ concentration, milk urea-N and fat yield (p<0.05). The cows fed diets based on WBC silage experienced greater rumination time than the cows fed corn silage (p<0.05). Conclusion: Administering additives to silages to reduce uNDF may improve the performance of Holstein dairy cows.

• Journal of The Korean Society of Grassland and Forage Science
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• v.44 no.2
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• pp.106-112
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• 2024

The objective of this study was to compare the feeding effects of imported timothy hay, domestic Italian ryegrass silage (IRGS) and IRG dried by hot-air dry system (IRGHDS) under basic total mixed ration (bTMR) on rumination activity, milk production, and milk composition in lactating dairy cows. Eighteen Holstein dairy cows were divided into three groups: control (bTMR + imported timothy hay), treatment 1 (bTMR + IRGS) and treatment 2 (TMR + IRGHDS) groups. The study was conducted over a total period of 24 days, including a 10 days adaptation period and a 14 days main experimental period. The results indicate body weight was not significantly different between the three groups (p>0.05), and rumination time was significantly higher in the treatment 1 group compared with the control group (p<0.001). Milk fat, protein, and lactose were not significantly different between the three groups (p>0.05), however, somatic cell counts were significantly lower in the treatment 1 group compared with the control group (p<0.001). As a result of the economic feasibility analysis, it is expected that feeding TMR using IRGS and IRGHDS will increase profit by 402.8 won/day and 331.4 won/day per cow compared to imported timothy hay. Therefore, IRGS and IRGHDS can be used as substitutes for imported timothy hay in feeding lactating dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.8
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• pp.1159-1163
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• 2008

Data of 42 balance measurements from dry and lactating Holstein cows and blood and urine samples from 24 Japanese Black cows were collected to evaluate the potential for predicting urinary nitrogen (N) excretion from plasma urea nitrogen (PUN). Similar positive correlations were obtained between N intake and apparent N absorption in dry and lactating cows. The regression equations of N intake on urinary N excretion varied in dry and lactating cows, and the difference of urinary N excretion between dry and lactating cows was due to the N secretion into milk. Highly positive correlations were observed between urinary N contents and urinary urea N in Japanese Black cows, and urinary urea N increased with increasing PUN. There were positive correlations between N intake and PUN in dry and lactating cows, but PUN and urinary N excretion in lactating cows were higher than in dry cows. There were positive correlations between PUN and urinary N excretion per BW in dry and lactating cows. Although urinary N excretion could be calculated as (N clearance rate of kidneys)PUNBW, high N clearance rate of kidneys, such as 2.08 L/d/kg BW, may be suitable to calculate urinary N excretion in lactating cows, compared with 1.33 L/d/kg BW in dry cows.

• Korean Journal of Animal Reproduction
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• v.7 no.2
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• pp.8-26
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• 1983

Various early pregnancy diagnostic methods have been developed in order to improve the reproductive efficiency in cow, mare, mule, sow, sheep, goat, dog, cat, rabbit, buffalo, camel, elephant, monkey, deer, lion, coipus and guinea pig. These methods include abdominal swelling, abdominal palpation, esturs cylce detection, Lupin test, gonadotropin assay, colostrum injection test, sperm motility assessment, cervical mucus viscosity test, Kaber chromagens method, estrogen test, A Scheim-Zond다 test, spectrophotometric detection of estrogen in urine and feces, boric acid crystraline formation test in urine, oxytocin injection test, diamino-oxidase test, PMSG HA test, behaviour test, Simolus iodine detection test, detection of tryptophane in urine, x-ray method, Cuboni and Lunaas method, vaginal biopsy method, Friedmann Schneider diagnostic method, electrode method, barium chloride detection method, ECG, Doptone method, ultrasound method, ultrasound scanning method, LDH method, rectal palpation method, CL palpation method, radioautography, serum creatine test, serum globulin test, chlormadine method, CAP method, Medata Do, pp.ers method, body fluid test, Plasma oCS detection method, ERIA, LHRH method, negative latex cogulation test and oestrone sulphate detection method. The most reliable methods with high a, pp.icability to farm animals such as sheep, mare, sow and cow are rectal palpation, ultrasound method and hormonal assay in blood and milk. However, they require complicated laboratory works for the early diagnosis of pregnancy and in most cases, the simple and economical methods which are described up to now need a long period of time after conception. Generally, it is possible to detect pregnancy after one estrus cycle, even though it varies depending on the species of animals. For improvement of the reproductive efficiency, it is required to develop a more accurate, economical, simple and early detectable method. It is anticipated that the result of a study on the detection method of EPF(early pregnancy factor) would be a, pp.icable to various animals within 6 hours after conception.