• Journal of Biosystems Engineering
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• 제33권2호
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• pp.130-135
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• 2008

The purpose of this study was to develop a preprocessor for real-time portable quality evaluation system of milk. The preprocessor consisted of two flow pump to supply milk sample and reaction reagent at given volume, a fan to mix milk with reaction reagent, a thermoelectric device to maintain sample temperatures of $40^{\circ}C$, and I/O interface to control signals. The tests conducted with different level of flow rate of pump, fan speed, ambient temperature, and intial temperature of mixtures. To evaluate performance of the preprocessor, the supplied volumes, color changes, and temperatures were measured and analyzed. The results showed that the preprocessor could control supplying volumes, mixing, temperatures of samples automatically. The preprocessor showed good performance to be used for portable quality evaluation system of milk.

• 한국축산시설환경학회지
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• 제20권1호
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• pp.15-20
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• 2014

The present study was conducted to develop a milk filtering system for decreasing somatic cell count (SCC) in bulk tank milk. The pore sizes of the filter were 0.1, 0.3, 0.4, 0.5 and $0.8{\mu}m$. The rate of SCC reduction of $1^{st}$ grade milk on $0.1{\mu}m$ filter was 76% and significantly higher than other treatments. The rates of SCC reduction for 0.3, 0.4, 0.5 and $0.8{\mu}m$ were 35, 32, 18 and 6.4%, respectively. The effects of the milk filtering system on bacterial count and milk fat content were minimal. The milk flow rates per minute between the filter sizes were similar. But discharge pressures were increased as the pore size of the filter decreased. In conclusion, Considering the rate of SCC reduction, discharge pressure and cost, $0.4{\mu}m$ filter could be recommended.

• Asian-Australasian Journal of Animal Sciences
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• 제16권1호
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• pp.88-95
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• 2003

The objective of the present study was to determine the effect of exogenous bovine somatotropin on the mammary function in late lactating crossbred Holstein cows. Twelve 87.5% late lactating Holstein cows, approximately 30 weeks postpartum, were divided into two groups of 6 animals each. Animals in the control group were given sodium bicarbonate buffer by subcutaneous injection, while animals in the treated group were given recombinant bovine somatotropin (bST) by subcutaneous injection with 500 mg of bST (14 day prolonged-release bST). After bST injection, milk yield significantly increased from the control level on day 8 to day 20 (p<0.05) with a concomitant increase in mammary blood flow (p<0.01). An increase in mammary blood flow in response to bST treatment was greater than an increase in milk production. An increased plasma concentration of IGF-I coincided with an increase in mammary blood flow in animals treated with bST. There were no significant changes in the concentration of arterial plasma glucose concentration, the arteriovenous concentration difference (A-V difference) and mammary extraction ratio while the mammary glucose uptake increased when compared to the control group. The concentration of arterial plasma triglyceride decreased throughout the experimental period in animals give bST. The plasma concentration of acetate, and the mammary uptake for acetate significantly increased (p<0.05) after bST treatment. The action of bST did not affect the plasma concentration, A-V difference and extraction ratio across the mammary gland for $\beta$-hydroxybutyrate. The concentrations of milk fat and lactose tended to increase during bST treatment. Milk protein concentration initially increased in the first few days and decreased after bST injection when compared to the pretreated period. The present results indicated that bST could affect the mammary function in late lactating cows by increase in milk yield involving changes in both extra-mammary and intra-mammary mechanisms. The exogenous bST exerted its galactopoietic action through an increase in circulating IGF-I of the late lactating Crossbred Holstein cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제9권2호
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• pp.165-170
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• 1996

Two experiments were conducted to search factor(s) affecting the plasma allantoin concentration in infant calves. In experiment 1, five male Holstein calves aged 1 week were given only milk replacer free from nucleic acids for 28 days Plasma allantoin concentration varied in a reverse proportion to daily amounts of milk replacer, and the concentration when calves received 750 g/d of milk replacer was significantly lower than that when they received 250 g/d. Contrary to plasma allantoin concentration, glomerular filtration rate(GFR) was directly proportional to daily amounts of milk replacer, leading to a constant filtration of allantoin across the glomeruli. Renal handling of allantion was also unaffected by the amount of milk replacer, resulting in the constant urinary excretion of allantoin. These results suggested that GFR, which was affected by the nutritional status, could affect plasma allantoin concentration. In experiment 2, the effect of age-related changes in nutritional status after weaning on GFR was examined in eight calves weaned at 5 weeks of age. The GFR expressed as body weight basis was lower immediately after weaning, but linearly increased up to the 19th week post-weaning. The present results suggested that the changes in GFR in response to nutritional status would be one of the possible causes of atypical plasma allantoin concentration immediately after weaning. We conclude that plasma allantoin concentration would not be a proper estimator of intestinal flow of microbial protein in cattle.

• Asian-Australasian Journal of Animal Sciences
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• 제18권11호
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• pp.1600-1608
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• 2005

The study was carried out to evaluate the effect of exogenous bovine somatotropin on water metabolism in relation to mammary function in early lactation of crossbred Holstein cattle. Ten, 87.5% crossbred Holstein cattle were divided into two groups of 5 animals each. At day 60 of lactation, the control group was given placebo while animals in the experimental group were given recombinant bovine somatotropin (rbST) by subcutaneous injection with 500 mg of rbST (14-days prolonged-release rbST). In rbSTtreated animals, milk yield increased 19.8%, which coincided with a significant increase in water intake (p<0.01), while DM daily intake was not different when compared to the control animals. Water turnover rate as absolute values significantly increased (p<0.05), while the biological half-life of water did not change in rbST-treated animals. Total body water (TBW) and total body water space (TOH) as absolute values significantly increased (p<0.01) in rbST-treated animals, while it was decreased in the control animals. Absolute values of empty body water (EBW) markedly increased (p<0.05), which was associated with an increase in the extracellular fluid (ECF) volume. Absolute values of plasma volume and blood volume were also significantly increased (p<0.05) in rbST-treated animals. The increase in mammary blood flow in rbST-treated animals was proportionally higher than an increase in milk production. The plasma IGF-1 concentration was significantly increased (p<0.01) in rbST-treated animals when compared with those of control animals during the treatment period. Milk fat concentration increased during rbST treatment, while the concentrations of both protein and lactose in milk were not affected. The present results indicate that rbST exerts its effect on an increase in both TBW and EBW. An increased ECF compartment in rbST-treated animals might partly result from the decrease in fat mass during early lactation. The action of rbST on mammary blood flow might not be mediated solely by the action of IGF-1 for increase in blood flow to mammary gland. An elevation of body fluid during rbST treatment in early lactation may be partly a result of an increase in mammary blood flow in distribution of milk precursors to the gland.

• 한국식품과학회지
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• 제17권6호
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• pp.500-505
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• 1985

농축우유에 냉동보호물질을 첨가하여 $-15^{\circ}C$에서 비동결 상태로 저장할 수 있는 방법을 개발하여, $-15^{\circ}C$에서 저장하면서 저장중 품질변화를 평가한 결과는 다음과 같다. 농축우유를 $-15^{\circ}C$에서 비동결 상태로 저장하는데 적합한 복합냉동보호물질은 설탕 17.74%, glucose, 8.87% fructose 8.87%, glycerol 2%, HMP 0.25%, NaCl 0.25%, ascorbic acid 0.02%로 구성되었으며, 고형분 38%인 농축우유에 냉동보호물질 38%를 첨가하는 것이 적당하였다. 저장중의 품질변화중 관능적 품질과 이용성에 가장 심각한 영향을 주는 것은 단백질 변성에 의한 gel화현상 이었다. Gel화현상은 대조구에서 3주저장 후부터 발생하였으나 냉동보호물질을 첨가한 처리구에서는 전 저장기간동안 발생하지 않았다. 우유 단백질의 저장중 변성현상을 뒷받침하는 단백질 침전량을 조사한 결과 control에서 3주 후부터 현저하게 나타났으며, 처리구에서는 저장기간동안 나타나지 않아TEk. 저장중 농축우유의 색깔변화나 과산화물가의 변화는 경미했으며, 대조구과 처리구간에 유의성있는 차이가 없었다. 이상의 결과를 종합해 보면 농축우유에 냉동보호물질을 첨가하여 냉동저장온도에서 비동결상태로 저장하면 통상적인 냉동저장방법과 같은 품질보존 효과를 얻을 수 있을 뿐만 아니라, 보통 냉동저장시에 발생하는 우유단백질의 변성에서 오는 gel화현상을 효과적으로 방지할 수 있어 저장 후 제품의 품질과 이용성을 증진 시킬 수 있었다.

• 대한수의학회지
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• 제42권4호
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• pp.485-493
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• 2002

The purpose of this study was to develope a computer program to help with gross diagnosis of protein-energy balance and feeding management practice and with the prediction about the risk possibility of productive disease such as reproductive and metabolic disorders by evaluating fat, protein, and milk urea nitrogen (MUN) from individual cow milk in dairy herd Somatic cell counts also represent the condition of udder health. The principal flow charts of this program was to check on herd management, sampling the composite milk, analysis the milk composition, conversion of data from milking equipment to program, input and analysis of data in program, and report. This program is compatible with window 95/98 system. The major analytical elements of this program were presented as; the profile of herd lactation curve analysis of the test-day milk production level, the distribution of somatic cell count, the fat to protein ratio to evaluate body energy balance, and the interpretation of dietary protein-energy balance by milk protein and MUN contents for individual cows. This program using milk fat, protein, MUN, and somatic cell counts will serve as a monitoring tool for the protein-energy balance and the feeding management practice, and for distribution of mastitis in individual cows. It will also be used to manage the nutritional and reproductive disorders and mastitis at the farm level.

• 한국축산식품학회지
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• 제44권2호
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• pp.372-389
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• 2024

This study investigated the efficacy of ultraviolet-C (UV-C) irradiation in enhancing the quality of raw bovine milk by targeting microbial populations and lipid peroxidation, both of which are key factors in milk spoilage. We categorized the raw milk samples into three groups based on initial bacterial load: low (<3 Log 10 CFU/mL), medium (3-4 Log 10 CFU/mL), and high (>4 Log 10 CFU/mL). Using a 144 W thin-film UV-C reactor, we treated the milk with a flow rate of 3 L/min. We measured the bacterial count including standard plate count, coliform count, coagulase-negative staphylococci count, and lactic acid bacteria count and lipid peroxidation (via thiobarbituric acid reactive substances assay) pre- and post-treatment. Our results show that UV-C treatment significantly reduced bacterial counts, with the most notable reductions observed in high and medium initial load samples (>4 and 3-4 Log 10 CFU/mL, respectively). The treatment was particularly effective against coliforms, showing higher reduction efficiency compared to coagulase-negative staphylococci and lactic acid bacteria. Notably, lipid peroxidation in UV-C treated milk was significantly lower than in pasteurized or untreated milk, even after 72 hours. These findings demonstrate the potential of UV-C irradiation as a pre-treatment method for raw milk, offering substantial reduction in microbial content and prevention of lipid peroxidation, thereby enhancing milk quality.

• 대한수의학회지
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• 제44권3호
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• pp.367-371
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• 2004

This report describes the determination of ceftiofur residues in milk from treatment of lactating dairy cattle by intramuscular injection of three consecutive daily doses of about 1 mg /kg BW, the recommended label dosing. The separation of ceftiofur was achieved on $C_1_8$ reverse phase column. The mobile phase consisted of 0.1% trifluoracetic acid in water (A) and 0.05% acetic acid in acetonitrile (B) and grediently flowed at the flow rate of 0.4 mL/min. As a result of analysis of blank raw bovine milk samples, matrix interference was not shown. Limit of detection and limit of quantitaion was 0.5 ng/mL and 1 ng/mL, respectively. The values of precision and recovery satisfied the guideline of National Veterinary Research and Quarantine Service (NVRQS, Korea). The mean residual concentration of ceftiofur in milk did not exceed 3.71 ng/mL when ceftiofur was administered intramuscularly to lactating dairy cattle for 3 consecutive days at 1 mg/kg of BW per day. It is much lower than the proposed MRL (100 ng/mL) of ceftiofur in milk.

• 한국미생물·생명공학회지
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• 제6권3호
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• pp.109-113
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• 1978

효소에 의한 우유의 응고과정은 효소적인 단계와 비효소적인 단계의 두 가지로 구성되어 있다는 사실이 확인되었다. 효소적인 단계가 끝나는 점을 시험관속에서 반응을 시킨 다음 그 시험관을 5도의 경사까지 기울었을 때 우유가 시험관 벽을 타고 흐를수 있는 거리를 가지고 측정하였다. 효소적인 단계에 소요되는 반응시간을 측정하므로서 응유효소의 역가를 평가하는 새로운 방법이 제시되었다.