• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1122-1127
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• 2019

Objective: The objective of current study was to investigate the lactation performance and rumen fermentation characteristics of dairy cows fed a diet with alfalfa hay replaced by corn stover but supplemented with molasses. Methods: Sixteen Holstein cows in mid-lactation were randomly assigned to 1 of 2 dietary treatments: i) alfalfa based diet (AH), and ii) corn stover based diet supplemented with molasses (CSM). The experiment was conducted according to a $2{\times}2$ crossover design with 22-d each period, consisting of 17 d for adaptation and 5 d for data and samples collection. Results: Dry matter intake and milk yield were higher for cows fed AH than CSM (p<0.01). Milk protein content and nitrogen conversion were higher (p<0.05), while milk urea nitrogen was lower (p<0.01) for cows fed AH than CSM-fed cows. Contents of milk total solids, fat and lactose were not different between two groups (p>0.10). Total rumen volatile fatty acid concentration tended to be higher (p = 0.06) for cows fed AH than CSM-fed cows. Molar proportion of acetate was lower (p = 0.04), but valerate was higher (p = 0.02) in cows fed AH than CSM-fed cows. Rumen concentration of propionate, and isobutyrate, and ratio of acetate to propionate tended to be different (p<0.10) between two groups. The feed cost per kilogram of milk was lower in CSM than AH (p<0.01). No differences were found in feed efficiency and most plasma parameters tested (p>0.10). Conclusion: In comparison with AH diet, CSM diet could be fed to dairy cows without negative effect on feed efficiency, ruminal fermentation, but economically beneficial, indicating that CSM could be an alternative choice for dairy farms instead of AH to feed midlactation dairy cows.

• Journal of Life Science
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• v.14 no.5
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• pp.747-751
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• 2004

The effect of yogurt containing Hamcho (Salicornia herbacea) extract (Hamcho yogurt: HY) on the lipid concentrations in male Sprague-Dawley rats fed a cholesterol diet were studied. Rats were assigned three groups in the experiment; cholesterol diet (the CHOL group), cholesterol diet plus yogurt by lactic acid bacteria (the Y group) or cholesterol diet plus yogurt supplemented Hamcho extract by lactic acid bacteria (the HY group). Fermented milk with or without Hamcho extract in the diet supplemented at the levels 5.0% for 3 weeks. The concentrations of total cholesterol and bile acid in serum was significantly lower in the HY group than the CHOL group. This effect was also observed in rats fed a diet supplemented fermented milk. This cholesterol-lowering effect was more pronounced in the HY group compared to the Y group. The atherogenic index was significantly lower in the HY or Y groups than the CHOL group. The concentration of non esterified fatty acid in serum was significantly lower in the HY group than the CHOL and the Y groups. These results suggested that Hamcho yogurt exert the hypocholesterolemic effect in cholesterol fed rats.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.188-194
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• 2002

To study the effect of wheat bran and lactic acid producing bacteria (LAB) on the performance of calves, 20 crossbred male cattle calves (day old), distributed into two groups were fed on calf starters containing 50 or 0% maize grain, along with green berseem ad libitum and milk as per body weight. Each group was further divided into two sub groups and one subgroup of each group was supplemented with mixed culture of LAB (Lactobacillus acidophilus L. casei, L. Jugarti). Milk feeding was discontinued after 8 weeks of age. The addition of culture increased (p<0.05) DM intake in calves receiving grainless diet from eighth week to the thirteenth one. There was about 21% higher body weight gain and 14% lower feed : gain ratio in culture supplemented calves. DM digestibility was significantly lower (p<0.05) in calves getting grain without culture. The crude protein NDF and ADF digestibility was higher (p<0.05) in grainless than the grain fed group. No major change on rumen fermentation pattern among different treatments was found. The concentration of total volatile fatty acids (TVFA) and protozoa count was higher (p<0.05) in grain fed group. However, lactic acid concentration was higher and rumen pH was lower due to culture feeding. The incidence as well as severity of diarrhoea was reduced in culture supplemented group. The results indicate that crossbred calves can be reared successfully on grainless diet and berseen fodder. The performance of calves was also improved by LAB supplementation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.4
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• pp.466-475
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• 2005

Docosahexaenoic acid (22:6n-3, DHA) is highly enriched in membrane of brain and retina, and plays an important role in maintaining an optimal function of the central nervous system. We investigated the effect of n-3 fatty acid deficiency on rat brain, retina and liver fatty acyl composition at two different ages (3 wks and 15 wks) under DHA deficient condition. Rat pups born to dams fed a diet with $3.1\%$ of total fatty acids as $\alpha-linolenic$ acid (LNA) were fed using an artificial rearing system either an n-3 deficient (n-3 Def) or n-3 adequate (n-3 Adq) diet. Both diets contained $17.1\%$ linoleic acid (LA) but the n-3 Adq diet also contained $3.1\%$ LNA. Rats consuming the n-3 Def diet showed a lower brain $(50\%\;in\;13\;wks\;and\;70\%\;in\;15\;wks,\;p<0.05)$ and retinal $(50\%\;in\;13\;wks\;and\;63\%\;in\;15\;wks,\;p<0.05)$ DHA than those on the n-3 Adq diet, which was largely compensated for by an increase in docosapentaenoic acid (22:5n-6, DPAn-6). In the liver of the n-3 Def group, the percentage of DHA decreased by $97\%$ at 3 wks of age with an apparent increase in DPAn-6 relative to the n-3 Adq group (p<0.05), while there was a $65\%$ lower liver DHA in n-3 Def group at 15 wks of age than the n-3 Adq group (p<0.05). Liver arachidonic acid (20:4n-6, AA) was increased at 3 wks of age but decreased at 15 wks of age in the n-3 Def group compared with n-3 Adq group (p<0.05). In conclusion, the replacement of DHA by DPAn-6 in brain and retina fatty acid composition may be related to the suboptimal function in spatial learning, memory and visual acuity. This artificial rearing method presents a first generation model for n-3 deficiency that is similar to the case of human nutrition that commonly employed two generation model.

• Korean Journal of Veterinary Service
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• v.38 no.3
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• pp.155-162
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• 2015

The incidence of second-grade milk production in 9 dairy farms of South Korea was investigated from May 2011 to March 2012, and the serum composition of cows producing first- and second-grade milk in 14 farms including the 9 farms was analyzed. The incidence rate of second-grade milk production of 402 cows in nine dairy farms located in the central and southwestern regions of Korea was 15.4% with the highest rate being 34.4%. Seasonal morbidity was higher during late winter (February) and early summer (June) with the highest rate observed in February (32.6%) followed by November (33.3%). Second-grade milk was most frequently found within one month postpartum (34.1%) while only 3.5% was found during the first 60~90 days of lactating period (n=785, 5 herds). The morbidity increased thereafter (P<0.05) with the highest observed between 270~300 days of lactation (36.1%). The acidity was not significantly different between second-grade ($0.159{\pm}0.026%$) and first-grade milk ($0.158{\pm}0.027%$). Blood serum analysis of 371 cows in the 14 dairy farms indicated that aspartate aminotransferase (AST) level was significantly higher (P<0.001) in cows producing second-grade milk while albumin was significantly lower (P<0.001) than cows producing first-grade milk. Total protein and triglyceride was also significantly low along with glucose, non-esterified fatty acid and blood urea nitrogen in cows producing second-grade milk. Statistical analysis including sensitivity, specificity and positive/negative prediction values showed that lactating cows with high AST, low albumin, total protein and triglyceride levels in the serum tended to produce second-grade milk. It was concluded that serological parameters, especially live functional and metabolic-related serum compositions (AST, albumin, total protein and triglyceride), were significantly influenced in cows producing second-grade milk.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.9
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• pp.1295-1303
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• 2013

The aim of this study was to determine the effect of different physical forms and urea treatment of rice straw on feed intake, rumen fermentation, and milk production. Four, multiparous Holstein crossbred dairy cows in mid-lactation with initial body weight (BW) of $409{\pm}20kg$ were randomly assigned according to a $4{\times}4$ Latin square design to receive four dietary treatments. The dietary treatments were as follows: untreated, long form rice straw (LRS), urea-treated (5%), long form rice straw (5% ULRS), urea-treated (2.5%), long form rice straw (2.5% ULRS) and urea-treated (2.5%), chopped (4 cm) rice straw (2.5% UCRS). Cows were fed with concentrate diets at a ratio of concentrate to milk yield of 1:2 and rice straw was fed ad libitum. The findings revealed significant improvements in total DM intake and digestibility by using long and short forms of urea-treated rice straw (p<0.05). Ruminal pH was not altered among all treatments (p>0.05), whereas ruminal $NH_3$-N, BUN and MUN were found to be increased (p<0.01) by urea-treated rice straw as compared with untreated rice straw. Volatile fatty acids (VFAs) concentrations especially those of acetic acid were decreased (p<0.05) and those of propionic acid were increased (p<0.05), thus acetic acid:propionic acid was subsequently lowered (p<0.05) in cows fed with long or short forms of urea-treated rice straw. The 2.5% ULRS and 2.5% UCRS had greater microbial protein synthesis and was greatest when cows were fed with 5% ULRS. The urea-treated rice straw fed groups had increased milk yield (p<0.05), while lower feed cost and greater economic return was in the 2.5% ULRS and 2.5% UCRS (p<0.01). From these results, it could be concluded that 2.5% ULRS could replace 5% ULRS used as a roughage source to maintain feed intake, rumen fermentation, efficiency of microbial protein synthesis, milk production and economical return in mid-lactating dairy cows.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.4
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• pp.335-356
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• 1997

Injection of bovine growth hormone (bGH) to lactating dairy cows increases milk yield and yields of milk components including fat. It is generally believed that most of the anabolic effects derived from bGH in animal tissues are primarily mediated by IGF-1. IGF-1 is a strong anabolic peptide in the plasma of animals and exerts mitogenic and metabolic effects on target cells. Contrary to most protein hormones, the majority of IGF-1 in circulation is bound to the binding proteins (IGFBPs) which are known to be responsible for modifying the biological actions of IGF-1, thus making determinations of IGF-1 actions more difficult. On the other hand, fat is a major milk component and the greatest energy source in milk. Currently, the fat content of milk is one of the major criteria used in determining milk prices. It has been known that flavor and texture of dairy products are mainly affected by milk fat and its composition. Acetyl-CoA carboxylase (ACC) is the rate limiting enzyme which catalyzes the conversion of acetyl-CoA to malonyl-CoA for fatty acid synthesis in 1ipogenic tissues of animals including bovine lactating mammary glands. In addition to the short-tenn hormonal regulation of ACC by changes in the catalytic efficiency per enzyme molecule brought about by phosphorylation and dephosphorylation of the enzyme, the long-term hormonal regulation of ACC by changes in the number of enzyme molecules plays an essential role in control of ACC and lipogenesis. Insulin, at supraphysiological concentrations, binds to IGF-1 receptors, thereby mimicking the biological effects of IGF-1. The receptors for insulin and IGF-1 share structural and functional homology. Furthermore, epidermal growth factor increased ACC activity in rat hepatocytes and adipocytes. Therefore, it can be assumed that IGF-1 mediating bGH action may increase milk fat production by stimulation ACC with phosphorylation (short term) and/or increasing amounts of the enzyme proteins (long term). Consequently, the main purpose of this paper is to give the readers not only the galactopoietic effects of bGH, but also the insight of bGH action with regard to stimulating milk fat synthesis from the whole body to the molecular levels.

• Animal Bioscience
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• v.35 no.1
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• pp.13-21
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• 2022

Objective: The aim of the study was to evaluate the influence of gene polymorphisms and nongenetic factors on the somatic cell score (SCS) in the milk of Holstein (n = 148) and Simmental (n = 73) cows and their crosses (n = 6). Methods: The SCS was calculated by the formula SCS = log₂(SCC/100,000)+3, where SCC is the somatic cell count. Polymorphisms in the casein alpha S1 (CSN1S1), beta-casein (CSN2), kappa-casein (CSN3), beta-lactoglobulin (LGB), acyl-CoA diacylglycerol transferase 1 (DGAT1), leptin (LEP), fatty acid synthase (FASN), stearoyl CoA desaturase 1 (SCD1), and 1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6) genes were genotyped, and association analysis to the SCS in the cow's milk was performed. Further, the impact of breed, farm, year, month of the year, lactation stage and parity on the SCS were analysed. Phenotype correlations among SCS and milk constituents were computed by Pearson correlation coefficients. Results: Only CSN2 genotypes A¹/A² were found to have significant association with the SCS (p<0.05), and alleles of CSN1S1 and DGAT1 genes (p<0.05). Other polymorphisms were not found to be significant. SCS had significant association with the combined effect of farm and year, lactation stage and month of the year. Lactation parity and breed had not significant association with SCS. The phenotypic correlation of SCS to lactose content was negative and significant, while the correlation to protein content was positive and significant. The correlations of SCS to fat, casein, nonfat solids, urea, citric acid, acetone and ketones contents were very low and not significant. Conclusion: Only CSN2 genotypes, CSN1S1 and DGAT1 alleles did show an obvious association to the SCS. The results confirmed the importance of general quality management of farms on the microbial milk quality, and effects of lactation stage and month of the year. The lactose content in milk reflects the health status of the udder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.5
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• pp.569-577
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• 2007

The purpose of the present study was to propose some amendments on nutrient standard regulations of infant formula in Korea. For this purpose, we compared and analyzed the nutrient regulations of Korea, CODEX, U.S.A, Japan, EU, Australia and New Zealand. Some developing aspects of Korea's nutrient standard regulations for infant formula need to be examined as follows: firstly, both milk-based formula and soy-based formula standards would be unified into an infant formula, and the user of infant formula would be categorized for babies less than 6 month old. Secondly, nitrogen conversion factor of milk protein in the infant formula would be 6.38, which is the same as that of CODEX Revised Standard. Protein quantities could be differentiated by protein sources, and essential amino acids in human milk would be standardized according to protein contents. Thirdly, $\alpha$-linolenic acid, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) as essential fatty acids and trans fatty acid would be standardized in terms of the contents. Fourthly, it is recommended that the unit of vitamins and minerals would be changed from g/100 g to g/100 kcal, and individual vitamins and mineral would have their maximum values. Finally, 5 nucleotides (cytidine, uridine, adenosine, guanosine, inosine 5'-monophosphate) and fluoride would be required for the strengthening the immunity and the development of teeth, respectively. In conclusion, the scientific studies on amendment scheme of nutrient standard regulations of infant formula is very important to fortify nutritional completeness for Korean infants and young children.

• Food Science of Animal Resources
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• v.31 no.3
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• pp.477-483
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• 2011

In this study, the most preferred trans fatty acid analysis methods, AOAC 996.06 and the Korea Food and Drug Administration official method, were reviewed and modified to apply to dairy products and dairy products imported into the Republic of Korea for evaluating trans fatty acid (TFA) content. The Rose-Gottlieb method for total fat analysis was validated with accuracy and precision parameters by analyzing infant formula standard reference material provided by the National Institute for Standards and Technology. The accuracy and precision data satisfied the CODEX guidelines. TFAs were analyzed with a resolution of 1.5 for 45 min using the modified oven temperature program. This modified method was applied to 45 dairy products from 11 countries. Average TFA contents in these imported dairy products ranged from 0.1 to 5.4 g per 100 g product. The majority of dairy products imported into the Republic of Korea were cheeses. TFA contents in the cheeses were 0.1 to 2.4 g per 100 g cheese. TFA contents in other dairy products were 1.7 to 5.4 g per 100 g product. These TFAs content variations can be explained by the trans fatty acids naturally present in ruminant milk formed by bacterial bio-hydrogenation in the rumen of cows and the different vegetable fat used as ingredients in the final products.