• Journal of Dairy Science and Biotechnology
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• v.28 no.1
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• pp.53-59
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• 2010

The milk product is one of the major foods which provide calcium for nutritional requirement. In addition to calcium, it supplies diverse nutrients including protein, potassium, vitamin A, vitamin $B_1$, and vitamin $B_2$. Adequate calcium intake throughout lifetime ensures optimum bone density and prevents osteoporosis in old age by reducing loss of bone mineral during growth and aging. The nutritional deficiency of calcium intake and spreading of osteoporosis in Korean population accentuated necessity of adequate calcium intake through milk consumption. Obstruction of milk consumption due to lactose intolerance should be overcome by educational programs for adequate milk consumption and low-lactose milk product developments. Consumption of milk products was reported to prevent high blood pressure in clinical studies and epidemiological investigations. As the feeding of milk increased, the body weight and fat of animal decreased in animal studies. The epidemiological investigations revealed that there was a negative correlation between the amount of milk consumption and the body fat. When calcium was provided as dietary supplement in the clinical trials, the body weight and body fat of subjects decreased. When calcium was particularly supplied as a part of milk, the body weight reduction rate was augmented. Calcium, vitamin D, and conjugated linoleic acid have been reported to exert a role in reducing cancer. The paramount importance of milk in nutrition as a source of calcium and other invaluable nutrients emphasizes consistent supply of milk products to adults as well as adolescents by dairy industry.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.794-798
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• 2004

An attempt was made to improve the efficiency of growth and lactation performance of dairy heifers subjected to a stair-step growth scheme using rice straw as the sole roughage source. Twenty-four young Holstein heifers were randomly assigned to either control or test group. The control diet met the National Research Council (NRC) requirement, with heifers calving at 24 to 26 mo of age. The test group was individually fed according to a schedule of 3, 2, 4, 2, 5 and 2 mo in which feed intake was alternately 20% below or 25% above the NRC requirements. Heifers on the stair-step growth pattern gained more body weight and consumed less dry matter (10.80 and 11.22%, respectively), resulting an increasing growth efficiency compared with the control. Body condition, first estrus, first conception, services per conception and calving difficulty (data not shown) were not affected. Milk yield of the test group was 8.5% higher than that of the control group. During the early lactation period, the milk yield was significantly higher in the stair-step group than in that of the control group (p<0.05). Milk composition was not affected by compensatory growth induced by the stair-step scheme. Also, weight at calving and calf growth performance was not affected by stair-step growth. The results indicate that using rice straw as a sole roughage source in a stair-step compensatory growth scheme can contribute to the improvement of growth efficiency and early lactation performance.

• Food Science of Animal Resources
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• v.37 no.1
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• pp.44-51
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• 2017

Heat treatment of milk aims to inhibit the growth of microbes, extend the shelf-life of products and improve the quality of the products. Heat treatment also leads to denaturation of whey protein and the formation of whey protein-casein polymer, which has negative effects on milk product. Hence the milk heat treatment conditions should be controlled in milk processing. In this study, the denaturation degree of whey protein and the combination degree of whey protein and casein when undergoing heat treatment were also determined by using the Native-PAGE and SDS-PAGE analysis. The results showed that the denaturation degree of whey protein and the combination degree of whey protein with casein extended with the increase of the heat-treated temperature and time. The effects of the heat-treated temperature and heat-treated time on the denaturation degree of whey protein and on the combination degree of whey protein and casein were well described using the quadratic regression equation. The analysis strategy used in this study reveals an intuitive and effective measure of the denaturation degree of whey protein, and the changes of milk protein under different heat treatment conditions efficiently and accurately in the dairy industry. It can be of great significance for dairy product proteins following processing treatments applied for dairy product manufacturing.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.776-782
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• 2022

Corn-soybean meal diets are commonly used in the pork industry as a primary source of energy and protein. However, such a diet generally contains non-starch polysaccharides (NSPs) which present a challenge in finding ways to improve their availability and digestibility. Dietary multi-carbohydrases (MCs) have been proposed as an efficient approach to utilize NSPs, and can result in improved growth performance and host intestinal fitness. In this study, we evaluated the effects of MC in lactation diets on gut microbiota composition of lactating sows and their litters. The experimental design contained two dietary treatments, a diet based on corn-soybean meal (CON), and CON supplemented with 0.01% multigrain carbohydrases (MCs). Sow and piglet fecal samples were collected on days 7 and 28 after farrowing. Based on the results from 16S rRNA gene amplicon sequencing, MC led to changes in species diversity and altered the microbial compositions in lactating sows and their piglets. Specifically, the MC treatment induced an increase in the proportions of Lactobacillus in piglets. Clostridium and Spirochaetaceae showed a significantly reduced proportion in MC-treated sows at day 28. Our results support the beneficial effects of dietary carbohydrases and their link with improved production due to better host fitness outcomes and gut microbiota composition.

• Animal Bioscience
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• v.36 no.1
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• pp.53-62
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• 2023

Objective: In this study, metabolites that changed in the rumen fluid, urine and feces of dairy cows fed different feed ratios were investigated. Methods: Eight Holstein cows were used in this study. Rumen fluid, urine, and feces were collected from the normal concentrate diet (NCD) (Italian ryegrass 80%: concentrate 20% in the total feed) and high concentrate diet (HCD) groups (20%: 80%) of dairy cows. Metabolite analysis was performed using proton nuclear magnetic resonance (NMR) identification, and statistical analysis was performed using Chenomx NMR software 8.4 and Metaboanalyst 4.0. Results: The two groups of rumen fluid and urine samples were separated, and samples from the same group were aggregated together. On the other hand, the feces samples were not separated and showed similar tendencies between the two groups. In total, 160, 177, and 188 metabolites were identified in the rumen fluid, urine, and feces, respectively. The differential metabolites with low and high concentrations were 15 and 49, 14 and 16, and 2 and 2 in the rumen fluid, urine, and feces samples, in the NCD group. Conclusion: As HCD is related to rumen microbial changes, research on different metabolites such as glucuronate, acetylsalicylate, histidine, and O-Acetylcarnitine, which are related to bacterial degradation and metabolism, will need to be carried out in future studies along with microbial analysis. In urine, the identified metabolites, such as gallate, syringate, and vanillate can provide insight into microbial, metabolic, and feed parameters that cause changes depending on the feed rate. Additionally, it is thought that they can be used as potential biomarkers for further research on subacute ruminal acidosis.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.407-420
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• 2022

Chicken dominates meat consumption because it is low in fat and high in protein and has less or no religious and cultural barriers. Recently, meat quality traits have become the focus of the poultry industry more than ever. Currently, poultry farming is focusing on meat quality to satisfy meat consumer preferences, which are mostly based on high-quality proteins and a low proportion of saturated fatty acids. Meat quality traits are polygenic traits controlled by many genes. Thus, it is difficult to improve these traits using the conventional selection method because of their low to moderate heritability. These traits include pH, colour, drop loss, tenderness, intramuscular fat (IMF), water-holding capacity, flavour, and many others. Genome-wide association studies (GWAS) are an efficient genomic tool that identifies the genomic regions and potential candidate genes related to meat quality traits. Due to their impact on the economy, meat quality traits are used as selection criteria in breeding programs. Various genes and markers related to meat quality traits in chickens have been identified. In chickens, GWAS have been successfully done for intramuscular fat (IMF) content, ultimate pH (pHu) and meat and skin colour. Moreover, GWAS have identified 7, 4, 4 and 6 potential candidate genes for IMF, pHu, meat colour and skin colour, respectively. Therefore, the current review summarizes the significant genes identified by genome-wide association studies for meat quality traits in chickens.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.106-118
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• 1998

Whey is a natural product obtained during cheese production. With the advent of new technology, whey protein concentrates and whey fractions have become readily available and versatile food ingredients. Whey protein concentrates are highly functional ingredients that have gelling, emulsifying, whipping, water-binding and fat-replacement properties. New fractions derived from whey (such as alpha-lactalbumin, lactoferrin, lactoperoxidase and peptides) attract considerable interest worldwide because of their bioactive or health-enhancing properties. Some of these fractions also find new uses as natural antibiotic, natural preservative and immunity-enhancing agents. With the growth of the functional foods industry sector, an increasing number of manufacturers take advantage of whey's nutritional and functional benefits to develop successful new products. The United States is the world's largest single producer and exporter of whey products. In 1997, more than 1 million metric tons of whey products were manufacturers in the U.S.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.195-202
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• 2023

Protease is a widely used enzyme particularly in the detergent industry. In this research, we aimed to isolate alkaline protease-producing bacteria for characterization as a laundry detergent additive. The screening of alkaline protease production was investigated on basal medium agar plus 1% skim milk at pH 11, with incubation at 30℃. The highest alkaline protease-producing bacterium was 6BS15-4 strain, identified as Bacillus gibsonii by 16S rRNA gene sequencing. While the optimum pH was 12.0, the strain was stable at pH range 7.0-12.0 when incubated at 45℃ for 60 min. The alkaline protease produced by B. gibsonii 6BS15-4 using dairy effluent was characterized. The optimum temperature was 60℃ and the enzyme was stable at 55℃ when incubated at pH 11.0 for 60 min. Metal ions K⁺, Mg²⁺, Cu²⁺, Na⁺, and Zn²⁺ exhibited a slightly stimulatory effect on enzyme activity. The enzyme retained over 80% of its activity in the presence of Ca²⁺, Ba²⁺, and Mn²⁺. Thiol reagent and ethylenediaminetetraacetic acid did not inhibit the enzyme activity, whereas phenylmethylsulfonyl fluoride significantly inhibited the protease activity. The alkaline protease from B. gibsonii 6BS15-4 demonstrated efficiency in blood stain removal and could therefore be used as a detergent additive, with potential for various other industrial applications.

• Journal of Veterinary Clinics
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• v.41 no.1
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• pp.8-17
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• 2024

This study was conducted to explore the efficacy of bee venom as a treatment for mastitis and to determine the optimal dosage and treatment period. When 6 mg or 12 mg of bee venom was administered to each experimental quarter of mastitis in dairy cow, the clinical symptoms in the 12 mg quarter were noticeably improved compared to those in the 6 mg quarter. There was no significant difference in the somatic cell count (SCC) in the milk between normal and mastitis quarters between the 6 and 12 mg doses, but there was a steady decrease in the 12 mg-treated quarter (p = 0.34). To determine the treatment period, bee venom was administered for 2, 4, and 7 days. After administering 12 mg of bee venom for 7 days, the SCC in the milk was compared before 6 days and after 7 days, and the SCC was significantly decreased to less than 100,000 SC/mL after 7 days (p = 0.01). In addition, to investigate the efficacy of bee venom, the minimum inhibitory concentration for S. aureus, E. coli, and coagulase negative staphylococci was measured, and the results showed that Gram-positive bacteria were more sensitive to bee venom than Gram-negative bacteria, and treatment for Gram-negative bacteria was limited. As a result of this study, it was confirmed that a dose of 12 mg of bee venom and a treatment period of more than 7 days were required to treat mastitis, and that treatment with bee venom alone against Gram-negative bacteria was negative.

• Journal of Dairy Science and Biotechnology
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• v.26 no.1
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• pp.21-26
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• 2008

Since goat milk infant formula has been increased, it is expected that goat milk consumption would be increased. This review summarizes the characteristics of goat milk especially, milk fat, somatic cell count, and goaty flavor. Average milk fat content for one year of twelve goat milk farms was 3.6%, but $2.9{\sim}3.1%$ in summer, which means summer goat milk could not meet the 'Processing and Ingredient Standard for Animal Products'. More than 3.2% for goat milk fat content in 'Processing and Ingredient Standard for Animal Products' should be amended. In addition to, hygienic standard for goat milk should be newly established because goat milk has naturally higher somatic cell count with noninfectious factors. It is thought that 6-trans nonenal and some branched fatty acids are responsible for the goaty flavor. It is necessary to minimize goaty flavor from farm to table because goaty flavor is the most important factor for the promotion of goat milk industry.