• Journal of Dairy Science and Biotechnology
• /
• v.42 no.2
• /
• pp.23-34
• /
• 2024

Milk, which is often referred to as a healthy beverage, is the first food encountered at birth. During digestion, A1-type milk often leads to digestive disorders due to increased levels of 𝛽-casomorphin-7. It also tends to induce inflammatory responses in the gut immune system by altering the gut microbiota and triggering conditions such as diabetes and respiratory hypersensitivity. In contrast, A2-type milk is gaining attention because of fewer associated problems than A1 milk and its unique functional benefits. However, information on the efficacy of A2 milk relies primarily on limited clinical and animal trial data, and substantiating its efficacy and functional superiority remains a challenge. Therefore, various studies, including research on the distinctive efficacy and functions of A2 milk compared with conventional A1 milk and investigations into the mechanisms underlying its effects on human health following consumption, are necessary in the future.

• Journal of Animal Reproduction and Biotechnology
• /
• v.34 no.1
• /
• pp.30-34
• /
• 2019

Milk fever is a metabolic disease with manifestation of clinical signs due to hypocalcemia, which usually occurs within 48-72 h after delivery. However, even after a successful treatment of milk fever, recurrence of milk fever may occur, and studies on recurrent milk fever are still lacking. Accordingly, the present study was conducted for the purpose of identifying the characteristics of recurrent milk fever according to farm, season, parity, and dystocia that can cause physiological changes in the mother during peri- and postpartum periods. The analysis results showed that the incidence rate of initial and recurrent milk fever according to breeding farm was 5.7%-14.1% and 3.1%-7.2%, respectively, demonstrating a positive correlation between the initial and recurrent milk fever (r = 0.613, p < 0.01). With respect to season, the incidence rate of initial and recurrent milk fever during summer was 12.3% and 7.5%, respectively, which were significantly higher than that of other seasons (p < 0.05). In addition, the recurrence rate, the ratio of recurrence relative to initial milk fever, was highest during summer with 62.7%. Regarding parity, the incidence rate of initial and recurrent milk fever in 3rd parity was 11.1% and 5.8%, respectively, which was significantly higher than in 1st and 2nd parity (p < 0.05). Furthermore, the recurrence rate in 4th parity was 64.1%, showing a pattern of increase in incidence rate with increase in parity. Finally, there were no differences in the incidence rate of initial and recurrent milk fever according to eutocia and dystocia. The findings indicated that the incidence rate of initial milk fever should be reduced to effectively prevent the recurrent milk fever, while animals with 3rd parity or higher should be expected to occur high rate of recurrent milk fever, especially during summer, and the necessary preparations should be made for intensive treatment of such individuals.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.6
• /
• pp.989-993
• /
• 2007

A lactose-hydrolyzed milk with low sweetness was developed using nanofiltration. Raw milk was treated with 0.03% ${\beta}$-galactosidase at $4^{\circ}C$ for 24 h to hydrolyze lactose partially. The resultant lactose-hydrolyzed milk containing 0.43% lactose was then concentrated using a nanofiltration membrane to reach concentration factor of 2.13. The concentration factors and coefficients of retention of milk components in nanofiltration were determined. The concentration factor of milk fat was 2.20 which was the highest of the milk components. The coefficient of retention of calcium and riboflavin was 0.96 and 0.76, respectively. However, the coefficient of retention of glucose, galactose, and sodium was 0.21, 0.15, and 0.22, respectively. Raw milk was treated with 0.1% ${\beta}$-galactosidase at $4^{\circ}C$ for 40 h to hydrolyze lactose fully and then concentrated to reach a concentration factor of 1.6 by using nanofiltration. The concentrated milk was reconstituted with water. The lactose-hydrolyzed milk had sweetness similar to milk. The compositional ratios of crude protein, calcium, sodium, and riboflavin of lactose-hydrolyzed nanofiltrated milk to those of raw milk were 99%, 97%, 77%, and 80%, respectively. This study showed that nanofiltration of lactose-hydrolyzed milk to remove galactose and glucose did not cause significant loss of calcium. The lactose-hydrolyzed nanofiltrated milk contained 0.06% lactose and had sweetness similar to milk.

• Animal Bioscience
• /
• v.34 no.1
• /
• pp.2-11
• /
• 2021

Objective: The aim of the study was to evaluate the influence of polymorphic loci and other factors on milk performance and the technological properties of milk. Methods: The analysis was performed on Simmental and Holstein cows in field conditions (n = 748). Milk yield in kg, fat and protein percentage and yield were evaluated. Technological properties were evaluated by milk fermentation ability, renneting, and an alcohol test. Polymorphisms in the acyl-CoA diacylgycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), casein beta (CSN2), casein kappa (CSN3), and lactoglobulin beta genes were genotyped, and association analysis was performed. Results: The DGAT1 AA genotype was associated with higher milk, protein and fat yields (p<0.05). The MM genotype in the LEP gene was associated with a lower protein percentage and the W allele with a higher protein percentage (p<0.05). In cows with the FASN GG genotype, the protein percentage was higher, but the A allele was associated with higher milk, protein and fat yields than the G allele. The TT genotype in SCD1 was associated with the lowest milk, protein and fat yields and with the highest milk protein percentage (p<0.01). The T allele had higher values than the C allele (p<0.05) except for fat percentage. The genotype CSN3 AA was associated with a significantly heightened milk yield; BB was associated with a high protein percentage. The effect of the alleles on the technological properties was not significant. The CSN2 BB genotype was associated with the best alcohol test (p<0.01), and the renneting order was inverse. Milk from cows with the CSN2 A1A1 genotype was best in the milk fermentation ability. CSN3 significantly affected the technological properties. Conclusion: The findings revealed the potential of some polymorphic loci for use in dairy cattle breeding and for the management of milk quality. In field research, the pivotal role of farms in milk yield, composition and technological properties was confirmed.

• Korean Journal of Agricultural Science
• /
• v.16 no.1
• /
• pp.71-83
• /
• 1989

The purpose of this research are to forecast the demand and supply of milk in Korea, and to obtain information for attitudes affecting milk consumption, which is necessary to make a plan for increasing milk consumption in Korea. The estimation of the milk demand and production was made by the multiplicative decomposition method and the statistical function. Data on consumer were collected from 737 students who were attending primary school, middle school and university in Daejeon during the period of July 11 to July 21, 1988. The results obtained are as follows; 1. The prediction results showed that the production for milk will over supply 21,900 tons in 1,990, 70,800 tons in 1,995 by the multiplicative decomposition method and 45,400 tons in 1990, -51,500 tons in 1995 by the statistical function. 2. It was found that almost all the students awared milk as essential food-stuff of common food stuff for the Koreans. 3. Quite a few students were apt to believe that milk processors added water into fluid milk. 4. Most students showed obtaining information about the nutritional value of milk by school education and advertising of TV, Radio, and Printed media. 5. However, it was found that the advertising by TV, Radio, and Printed media did hardly give to consumers influences on the choice of a particular milk brand. Accordingly, the conclusions are as follows; 1. Need to provide consumers with well planned education programs on the nutritional value of milk. 2. Heavy brand advertising for fluid milk may mislead the understanding of consumer, since city milk is not much differentiated in Korea. Therefore the milk processors should put more efforts in generic milk promotion by reducing brand advertizement. 3. The milk processors should provide major portion of financing for generic milk promotion program.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.5
• /
• pp.670-677
• /
• 2004

Sixteen multiparous Holstein-Friesian crossbred cows in mid-lactation were blocked according to days in milk (DIM) and previous lactation and randomly assigned according to a Randomized Complete Block (RCB) design with four replications to receive four dietary treatments. The dietary treatments consisted of T1: No cassava hay (CH) or stylo 184 hay (SH) supplementation, supplementation of concentrate to milk yield at 1:2 (control), T2: Supplementation of 1 kg of CH/hd/d, supplementation of concentrate to milk yield at 1:2, T3: Supplementation of 1 kg of CH+SH/hd/d, supplementation of concentrate to milk yield at 1:2, T4: Supplementation of 2 kg of CH+SH/hd/d, supplementation of concentrate to milk yield at 1:3. All animals received Ruzi grass from a cut-and-carry system as roughage source. The feeding trial lasted for 9 weeks. The results revealed that DMI of concentrate of supplemented treatments were significantly lower (p<0.05) than those in the control, but there was no significant difference between T2 and T3. There was no significant difference in forage DM intake between the control and supplemented treatments. CP and NDF digestibility of supplemented treatments were significantly (p<0.05) greater than the control and there were no significant differences among supplemented treatments. Milk yield and 3.5% FCM (14.3, 14.5, 14.7 and 14.8; 13.9, 14.3, 14.3 and 14.6 kg/hd/d, respectively) were not significantly different among treatments. Milk protein percentage of supplemented treatments was significantly (p<0.05) higher than the control, but there were no significant differences among supplemented treatments. There was no significant difference in milk fat percentage between the control and supplemented treatments. However, milk fat percentage tended to be higher for supplemented animals as compared to the control group. There were also no significant differences in lactose, solids-not-fat and total solids percentages among treatments. Cows in supplemented treatments gave incomes over supplement cost (IOSC) of 2.72, 2.74 and 2.93 US$/hd/d, respectively which were greater than for cows on control treatment. Furthermore, IOSC were greatest for cows in T4 as compared to other treatments. Based on this study it was concluded that, feeding cassava hay solely or in combination with stylo 184 hay as a supplemental protein source could be a potential valuable strategy in small-holder dairy farming systems in the tropics. This strategic supplementation significantly reduced concentrate use, which resulted in improved milk yields and milk quality for the supplemented cows. Moreover, it resulted in higher economical returns through increased productivity and lower ratios of concentrate to milk yield, from 1:2 to 1:3.

• Journal of the Korean Dietetic Association
• /
• v.13 no.1
• /
• pp.61-72
• /
• 2007

In order to study milk preference and intake pattern of adolescents, the questionnaire survey was conducted with 929 middle and high school students residing in Chungnam cities through October and November 2004. Of the subjects, 56.3% liked milk or liked very much. They preferred chocolate and fruit-tasted milk to plain milk. Reasons for liking milk were for health and its taste, while the reasons of disliking were unpleasant smell and stomach upset. However those who disliked milk did like milk products such as ice-cream, yogurt or cheese. Of the students 35.1% drank milk 2 times or more a day, while 11.8% drank milk less than 2-3 times a month. As a whole they drank milk 8.6$\pm$6.7 times a week, of which 4.3$\pm$3.1 times for plain milk. Daily intake amount was estimated as 308$\pm$315mL. Middle-school students and boys drank more milk than high-school students and girls, respectively. Among the students 64.3% used to drink 1 cup of milk at a time, and 58.3% drank only milk without other foods. It was shown that 51.8% took milk school-serviced and their milk intake frequencies were higher than those of who were not given school milk service. Also milk intake frequencies was higher in students whose mother were housewives than in students whose mother had jobs. Milk preference, intake frequency, and one portion size showed significant and positive correlations each other. In conclusion, milk intake level of the subjects was insufficient and unpleasant smell and stomach upset were the main reasons which decreased milk preference and consumption. Students with low milk preference should be guided with how to drink milk deliciously, how to choose milk type and its products. It is also effective to go into school milk service and to provide milk at home anytime. As students like much fruit-tasted and chocolate milk, the milk processing industries should take their nutritional and health benefits into considerations importantly.

• Korean Journal of Community Nutrition
• /
• v.12 no.3
• /
• pp.223-234
• /
• 2007

This study was done to determine the trans fatty acid (tFA) composition of human milk from postpartum to sixth months after delivery, to investigate the tFA intake of lactating women, and to estimate the intakes of tFA by infants exclusively fed breast milk. A total of 27 lactating Korean women participated to this study voluntarily, gave their breast milk, and responded to an investigation of their diets. The lactating women consumed 2.3-2.8 g/d of tFAs over the period of the first, second, third, and sixth months postpartum, which was 3.4-4.9% of the total fat intake and 0.8%-1.2% of the total energy intake. The proportions of tFAs in the breast milk were 1.89% in colostrum, 1.78% in transitional milk, and 1.78-2.25 in mature milk of the first, second, third, and sixth months postpartum. The tFAs of the breast milk identified in this study were C16:1n9t, C18:1n9t, C18:2n6t12t, C18:2n6t12c, C18:2n6t12t and C18:2n6t11t. Among them, C18:1n9t was predominant, which made up 59.26% of all tFAs in cob strum, 62.36% in transitional milk, and 64.42% in mature milk. The proportion of total tFA was unchanged with time, although some significant differences were noted for individual tFAs. The percentages of C18:2n6t12c and C18:2n6c12t decreased over the study period. Estimated tFA intake of the exclusively breast-fed infants was 0.18 g/d when fed colostrum, 0.29 g/d when fed transitional milk, and 0.53 g/d when fed mature milk until the sixth month of postpartum. Those were 0.5%, 0.8%, and 1.1% of the total energy intake. The results in this study indicate that lactating Korean women consume not a large quantity of tFAs, secrete breast milk not containing much tFA, and the estimated intake of tFAs by infants fed exclusively breast milk is not great.

• Journal of Food Hygiene and Safety
• /
• v.9 no.2
• /
• pp.57-66
• /
• 1994

The benefits of milk on the rats supplemented with cholesterol and vitamin D2 in diet was investigated. A total of 150 male rats of Sprague-Dawley strain, 5 weeks of age, were divided into 6 groups with the diet. Cholesterol control group was fed the diet containing 1.0% choleterol and 50,000 IU/100 g of vitamin D2 for 24 months, and M0.5, M1, M2 and M5 of milk groups were fed the diet containing cholesterol, vitamin D2 and 0.5, 1, 2 and 5 of reference daily intakes of whole milk, respectively. No remarkable differences of growth, diet intake, and food effciency ratio among groups were observed though rats in cholesterol control group showed abrupt decrease of diet intake and body weight showed slightly higher relative organ weights than did the rats in control group. The rats in cholesterol control group showed the highest serum total cholesterol level. The rats in milk groups showed lower total cholesterol level and higher high density lipoprotein (HDL)-cholesterol fraction than did the rats in cholesterol control group though no tendency was observed among milk groups. In milk groups, aorta, heart, kidney and liver of rats showed milder calcification and necrosis or fat degeneration compared with those in cholesterol control group. The above results suggest that whole milk could have beneficial effect on the cholesterol-and -vitamin D2-induced atherosclerosis in rats.

• Korean Journal of Veterinary Service
• /
• v.15 no.2
• /
• pp.101-108
• /
• 1992

This study was carried out to investigate the effect of sulfamethazine and trimethoprim on TTC test in raw milk. Ten raw milks which does not contain any antibiotics were collected from milk farms and one hundred twenty raw milks which collected from three raw milk receiving stations and those milk samples were mixed up sulfamethazine and trimethoprim for TTC test. The results were as follows ; 1. Positive reactions of TTC test were shown above the concentration of 3, 000ppm for sulfamethazine and 10ppm for trimethoprim. 2. When the TTC test was conducted with trimethoprim and sulfamethazine mixture, a pair of the concentration of trimethoprim and sulfamethazine shown to positive reaction were 0.1-2, 000ppm, 0.5-1, 000ppm, 1.0-250ppm and 2.0-100ppm, respectively. 3. Of 120 raw milk samples tested, 16 samples(13%) were shown quasi-positive reaction when the trimethoprim at the concetration of 2ppm was added in the samples.