• Journal of Dairy Science and Biotechnology
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• 제15권1호
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• pp.27-32
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• 1997

Most lipids in milk are dispetsed as the form of fat globules. Apical portion of plasma membrane is coated with fat globules, which are synthesized from mammary epithelial cells and then secreted into the lumen. The unique phenomenon in separation of the plasma membrane from the cell is observed only in mammary system. It has been suggested that milk fat globule membrane(MFGM) is formed from endoplasmic reticulum, Golgi apparatus, secretory granule to plasma membrane. For this reason MFGM is important for nuderstanding the structure and function of biological membrane. Because MFGM also plays an important role in inhibition of lipase action, stimulation of nutrient digestion and absorption, emulsion or function as natural liposome, study of the major components in MFGM will provide the opportunity for more broad industrial uses of MFGM in the future.

• Journal of Animal Science and Technology
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• 제50권1호
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• pp.111-120
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• 2008

산양유의 비유기간 중 연평균 유지방 함량이 3.88% 이었으며, 동절기(4.2%) 보다 하절기 (3.8%)에 낮았다. 유지방 함유율이 높을수록 총고형분 함량도 비례하여 증가하였다. 산양유 원유를 24시간 냉장저장 하는 동안에 저급 유리지방산(C4:0~C10:0)은 106% 증가하였으며 중급 및 고급 유리지방산(C12:0~C18:1)은 203%로 높은 증가율을 보였다. 균질한 시유에 원유를 첨가하여 반응할 때에 저급 유리지방산은 22% 증가되었으며 중급 및 고급 유리지방산은 199% 증가되었다. Lipase의 종류에 따른 지방분해실험에서 calf lipase는 중급 및 고급지방산 9배 보다 저급지방산은 5.6배로 증가시켰다. 그러나 Candida rugosa lipase와 Pseudomonas fluorescens lipase는 저급 유리지방산이 각각 6배와 14배 증가하고, 중급 및 고급 유리지방산은 각각 34배와 162배 증가하여 중급 및 고급지방산을 더 잘 분해하는 것으로 나타났다. 산양유의 LPL 활성이 높을수록 유리지방산 생성량도 증가되어 유의적 상관관계(r=0.5635)를 보였으며 또한 산양유 이취가 높아지는 상관관계(r=0.5777)를 보였다. 유지방 함량이 낮을수록 LPL 활성은 높아지는 유의적 역 상관관계(r=－0.4627)를 보였다. 산양유의 palmitic acid 함량이 높을 경우 산양유 이취 강도가 증가하는 유의적 상관관계(r=0.7226)를 보였다.

• Journal of Animal Science and Technology
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• 제58권10호
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• pp.38.1-38.6
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• 2016

Background: Despite the importance of relationships between somatic cell score (SCS) and currently selected traits (milk, fat and protein yield) of Holstein cows, there was a lack of comprehensive literature for it in Iran. Therefore we tried to examine heritabilities and relationships between these traits using a fixed-regression animal model and Bayesian inference. The data set consisted of 1,078,966 test-day observations from 146,765 primiparous daughters of 1930 sires, with calvings from 2002 to 2013. Results: Marginal posterior means of heritability estimates for SCS ($0.03{\pm}0.002$) were distinctly lower than those for milk ($0.204{\pm}0.006$), fat ($0.096{\pm}0.004$) and protein ($0.147{\pm}0.005$) yields. In the case of phenotypic correlations, the relationships between production and SCS were near zero at the beginning of lactation but become increasingly negative as days in milk increased. Although all environmental correlations between production and SCS were negative ($-0.177{\pm}0.007$, $-0.165{\pm}0.008$ and $-0.152{\pm}0.007$ between SCS and milk, fat, and protein yield, respectively), slightly antagonistic genetic correlations were found; with posterior mean of relationships ranging from $0.01{\pm}0.039$ to $0.11{\pm}0.036$. This genetic opposition was distinctly higher for protein than for fat. Conclusion: Although small, the positive genetic correlations suggest some genetic antagonism between desired increased milk production and reduced SCS (i.e., single-trait selection for increased milk production will also increase SCS).

• 한국유기농업학회지
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• 제24권3호
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• pp.485-495
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• 2016

The aim of the present study was to determine the effect of dietary cultured wild ginseng root (CWGR) supplementation on goat milk composition and ginsenoside profiles. Sixteen Saanen dairy goats were allocated to two balanced groups based on lactation period, body weight ($38.6{\pm}3.2kg$), and dairy milk yield ($2.85{\pm}1.2kg$), and were kept in separate pens. Goats were fed a total mixed ration (TMR) feed (2.3 kg/d, dry matter basis) and 1.5 g of CWGR powder was supplemented in the experimental diet. The total feeding period was 3 weeks, and milk and blood samples were collected on the last three days of the experimental period. There was no effect of CWGR on daily milk yield and milk composition (fat, protein, lactose, and solid-not-fat). However, the CWGR-treatment group had significantly higher plasma IgG and protein contents than the control group (P < 0.05). Significant amounts of ginsenosides were observed in the milk of the CWGR-treatment group, whereas ginsenosides were not detected in the milk of the control group. In conclusion, dietary CWGR was a useful regimen to produce functional goat milk enriched in ginsenosides.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.231-237
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• 1994

Three concentrations of P (0.33, 0.43 and 0.54%) and two concentrations of Ca (0.60 and 0.97%) in ration dry matter were evaluated for effects on dry matter intake and on milk yield and composition using 24 Holstein cows. Cows were arranged in a $3{\times}2$ factorial experiment as an incomplete randomized block design with three 28-day periods. Each cow consumed at least one ration with each concentration of Ca. Dry matter intake, yield of 3.5% Fat Corrected Milk, and milk composition were not affected by concentration of P, but milk yield was greater when lowest concentration of P was fed (22.8 vs. 22.1 kg/day; p<0.07). Cows fed rations containing 0.60% Ca had greater milk (22.7 vs. 21.9 kg/day; p<0.02) and 3.5% Fat Corrected Milk yields (p<0.03) and slightly greater protein content than when fed 0.97% Ca. Dietary Ca:P ratios between 1.1:1 and 2.9:1 had no effect on dry matter intake, milk yield, or composition. Concentrations of P in plasma were within the normal range for all rations. Because cows had high dry matter intake, mean daily intakes of both P and Ca were greater than required for their level of milk yield.

• 한국축산식품학회지
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• 제41권1호
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• pp.8-15
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• 2021

Vegetarians have claimed and actively promoted the advantages of plant-based alternative milks as the best option for human nutrition and health, compared to the natural dairy milk. However, numerous scientific evidences and reports have demonstrated that the natural milk possesses more beneficial nutrients and bioactive components than artificially manufactured plant-derived milks. The biochemical and nutritional advantages and functionalities of natural dairy milk cannot be replaced by man-made or crafted plant-based beverage products. On the other hand, the tremendous increase in production and consumption of the plant-based alternative milks in recent years has led a serious business downturn in traditional roles and stability of the dairy industry, especially in the major dairy producing Western countries. Although plant-based milk alternatives may have some benefits on nutrition and health of certain consumers, the plant-derived alternative milks may not overshadow the true values of natural milk. Milk is not a high fat and high cholesterol food as animal meat products. Unlike plant-based alternative milks, natural milk contains many bioactive as well as antiappetizing peptides, which can reduce body weight. It has proven that taking low-fat, cultured and lactase treated milk and dairy products with other diversified nutritionally balanced diets have been shown to be healthier dietary option than plant-based milk/foods alone.

• Asian-Australasian Journal of Animal Sciences
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• 제11권3호
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• pp.255-259
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• 1998

Sixteen Friesian Cows were allocated equally into 4 groups in a $4{\times}4$ Latin square design to evaluate the effects of utilizing bean by-products on the feed intake and milk production. Cows were fed on 4.5% of their body weight fresh alfalfa; the remainder of their requirements were covered by one of 4 experimental concentrate treatments: 1) commercial concentrate (CC), 2) 70% CC + 30% bean hulls (BH), 3) 70% CC + 30% Polished bean (PB) and 4) 70% CC+ 15% BH + 15% PB. Results showed that the inclusion of bean hulls at 30% improved (p<0.05) milk yield, 4% fat corrected milk yield, feed conversion ratio and fat percent of the milk over the other treatments. Feeding cows on a commercial concentrate plus 30% BH or 30% PB or 15% from each of BH and PB decreased the cost of feed per kg milk by 13.6, 2.5 and 1.3 %, respectively, lower than those fed on the commercial concentrate.

• Asian-Australasian Journal of Animal Sciences
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• 제3권1호
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• pp.21-25
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• 1990

Fructo-oligosaccharides are found in many plants, such as onion, burdock and wheat. They are not well hydrolyzed by digestive enzymes in animals, but are peculiarly assimilated by Bifidobacterium and some useful bacteria. In our previous experiment (Kobayashi et al., 1987) it was suggested that they were effective in decreasing energy loss in the metabolism of dairy calves. In the present study, the effects of fructo-oligosaccharides on body weight, milk-yield and milk-components (fat, protein and solids-not-fat) were investigated in dairy cows. Lactating cows were fed a standard diet containing fructoligo saccharides at 18.70g, 9.35g and 0.0g (control) per 100kg body weight, day for three weeks. Neither treatments significantly affected any of the parameters examined. The fructo-oligosaccharides were assumed to be hydrolyzed by rumen microorganisms and hardly to affect the bacterium florae in the intestines of the lactating cows.

• Asian-Australasian Journal of Animal Sciences
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• 제30권5호
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• pp.660-665
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• 2017

Objective: The objective of the study was to determine the effects of increasing levels of metabolizable protein (MP) on lactation performance and nitrogen (N) efficiencies in lactating dairy cows. Methods: Nine multiparous cows in mid lactation [$113{\pm}25$ days in milk] received three treatments in a $3{\times}3$ Latin square design with a period length of 21 days. The treatments were three diets, designed to provide similar energy and increasing supply of MP (g/d) (2,371 [low], 2,561 [medium], and 2,711 [high] with corresponding crude protein levels [%]) 15.2, 18.4, and 20.9, respectively. Results: Increasing MP supplies did not modify dry matter intake, however, it increased milk protein, fat, and lactose yield linearly. Similarly, fat corrected milk increased linearly (9.3%) due to an increase in both milk yield (5.2%) and milk fat content (7.8%). No effects were observed on milk protein and lactose contents across the treatments. Milk nitrogen efficiency (MNE) decreased from 0.26 to 0.20; whereas, the metabolic efficiency of MP decreased from 0.70 to 0.60 in low to high MP supplies, respectively. The concentration of blood urea nitrogen (BUN) increased linearly in response to increasing MP supplies. Conclusion: Increasing MP supplies resulted in increased milk protein yield; however, a higher BUN and low MNE indicated an efficient utilization of dietary protein at low MP supplies.

• 한국초지조사료학회지
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• 제37권3호
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• pp.208-215
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• 2017

This study was designed to investigate the carryover effects of high-forage to concentrate (F: C) diet in bred heifers on feed intake, feed efficiency (FE) and milk production of primiparous lactating Holstein cows. The experiment was conducted for 589 days (d) from onset of pregnancy through to the end of first lactation. Twenty-four bred heifers (Body weight: $BW=345.8{\pm}45.4kg$ and $15{\pm}1.2mon$ of age) randomly assigned to two groups of 3 pens containing 4 heifers each and fed high forage (HF) diet with F: C ratio of 91.7: 8.3% and low forage (LF) diet with F: C ratio of 77.8: 22.2% throughout the pregnancy period. After calving, lactating cows were fed total mixed ration (TMR) based diet. No differences (p > 0.05) were observed in dry matter intake (DMI) of bred heifers and primiparous lactating cows in both HF and LF groups. The FE of mid-to-late lactation period was higher (p< 0.05) in HF than LF group. However, the HF group showed higher (p < 0.05) milk yield, 4 % fat corrected milk (FCM) and energy corrected milk (ECM) than LF group during the 305 d lactation. The LF group showed higher (p < 0.05) milk fat, crude protein (CP), milk urea nitrogen (MUN), solid not fat (SNF) and somatic cell count (SCC) than HF group. It is concluded that restriction of F: C ratio to 91.7: 8.3% to bred heifers has the potential carryover effects to maintain higher milk yield and FE with no adverse effect on feed intake and milk composition of primiparous lactating Holstein cows.