• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.311-317
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• 1998

A total of 1033 Brown Swiss and 610 Canadienne cows were phenotyped for the genetic variants ${\alpha}_{s1}$-casein, ${\beta}$-casein, ${\kappa}$-casein, ${\beta}$-lactoglobulin and ${\alpha}$-lactalbumin. In Brown Swiss, frequency distributions were: 97.3% B and 2.7% C variant of ${\alpha}_{s1}$-casein; 31.6% $A^1$, 51.8% $A^2$, 0.5% $A^3$ and 16.1% B variant of ${\beta}$-casein; 70.4% A, 29.3% B, and 0.3% C variant of ${\kappa}$-casein; 41.7% A and 58.3% B variant of ${\beta}$-lactoglobulin; and 100% B variant of ${\alpha}$-lactalbumin. Corresponding frequencies in Canadienne for those five milk proteins were: 98.6 and 1.4%;58.5, 33.5, 0.08 and 7.9%; 78.8, 21.1 and 0.1%, 42.4 and 57.6%; and 100%. Analysis of variance by least squares showed possible association between milk protein phenotypes and some lactational production traits. There were no significant association of phenotypes of ${\alpha}_{s1}$-casein, ${\beta}$-casein and ${\beta}$-lactoglobulin with milk yield, fat yield, protein yield, fat percentage and protein percentage in both breeds during the three lactations. In the Brown Swiss, ${\kappa}$-casein phenotype was associated with 305-day fat yield and protein yield during the first lactation. ${\kappa}$-Casein AB was associated with higher milk, fat and protein yield during the second lactation. During the third lactation, ${\beta}$-lactoglobulin AA in Canadienne cows was associated with higher protein content in the milk (3.70%) when compared to phenotypes AB (3.54%) and BB (3.64%).

• Food Science and Biotechnology
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• v.16 no.4
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• pp.565-571
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• 2007

This study was carried out to investigate an optimum condition for the high angiotensin-l converting enzyme (ACE) inhibitory activity and the yield on enzyme concentration, casein concentration, and hydrolysis time. The optimum condition was performed by response surface methodology for acquirement of casein hydrolysate of milk which shows high ACE inhibitory activity, Among 8 tested enzymes, Protamex showed the highest activation degree with 77.03 unit/g from casein. Their hydrolysis degrees of flovourzyme 500MG, protamex, mixture from 1% casein were 85.5, 88.5, and 93.5%, respectively. The ranges of enzyme concentration (0.25-1.25%), casein concentration (2.5-12.5%), and hydrolysis time (20-100 min) as 3 independent variables through preliminary experiments of the yield of casein hydrolysate and ACE inhibitory activity, and it shows optimum response surface at a saddle point. It shows enzyme concentration (0.64%), casein concentration (8.38%), and hydrolysis time (55.81 min) in the yield aspect and showed the highest activity at enzyme concentration (0.86%), casein concentration (5.97%), and hydrolysis time (63.86 min) in ACE inhibitory aspect. The $R^2$ value of a fitted optimum formula on the hydrolysis yield was 0.9751 as the significant level of 1%. The $R^2$ value of a fitted optimum formula on ACE inhibitory activity is 0.8398, and the significance is recognized in the range of 5%.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.274-276
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• 1999

Sardine oil was microencapsulated by spray drying method in wall systems containing corn syrup in combination with sodium casein or wheat protein. Analysis of microencapsulation yield of sardine oil was carried out by a modified soxhlet method which could reduce the extraction time of surface oil. Microencapsulation yield of sardine oil was ranged from 65.3 to 93.5 % depending on the sodium casein content.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.4
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• pp.515-520
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• 2010

The response of broiler chicks to intubation of nutrients (starch, casein, soybean oil or their combinations) into the crop immediately after hatch was evaluated for performance, intestinal development, meat yield and immune competence up to 35 d of age. A control group with no access to feed and two test groups fed either inert material (sawdust) or starter diet for the initial 24 h after hatch were compared with nutrient intubated groups (n = 7). A total of 300 broiler chicks were equally distributed to 10 dietary groups with 6 replicates of 5 chicks each. After 24 h of hatch, all groups were fed ad libitum the starter (0-21 d) and finisher diets (22-35 d). Results indicated that post-hatch intubation of starch into the crop significantly (p${\leq}$0.05) improved body weight (at 14 and 35 d of age), readyto-cook meat yields, weights of breast muscle and small intestine segments, cell-mediated immune response, ND titers and weight of bursa compared to chicks starved or fed sawdust during the initial 24 h after hatch. However, chicks with access to feed immediately after hatch or intubation of starch, soybean oil, starch+casein, starch+soybean oil or starch+casein+soybean oil exhibited similar positive effects. Intubation of casein either alone or in combination with soybean oil was superior to the starved or sawdust fed groups, but inferior to other groups for all the parameters studied. It was concluded from the study that intubation of starch individually or in combination with casein and/or soybean oil effectively circumvented the negative effects of post-hatch starvation for 24 h. Among the nutrients intubated, carbohydrate (starch) was better utilized by the chicks than protein (casein) or fat during the initial post-hatch period.

• Food Science of Animal Resources
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• v.25 no.3
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• pp.328-332
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• 2005

The effect of k-casein (k-CN) variant on milk production traits (milk yield, fat yield, protein yield, fat percentage and protein percentage) was estimated for 568 Holstein cows in the first lactation. The k-CN valiant were determined by PCR-RFLP (restriction fragment length polymorphism) technique at the DNA level. Single trait linear model was used for the statistical analysis of the data. Result of this study indicated that k-CN variant affected significantly milk yield (P<0.05) and protein yield (P<0.01). Animals with the BB variant produced 622kg milk more and had protein yield higher by 32kg compared with animals with the AA variant No associations between the k-CN variants and other milk production trait were found. Therefore, milk and protein yield may be improved through milk protein typing by increasing the frequencies of k-CN B variant in dairy cattle population. In cheese making, it will be also preferable to have milk with the B variant of k-CN, which gives higher yield having a better quality than the A variant milk.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.983-988
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• 2007

The aim of this study was to examine the correlation between bovine casein (CN) mRNA expression levels in mammary epithelial cells and lactation period, the yields of milk proteins and other parameters. The cells were collected from each cow's milk, which contained somatic cell counts (SCC) of less than 100,000 cells/ml. The levels of ${\alpha}s1-$, ${\alpha}s2-$, ${\beta}$- and ${\kappa}$-CN mRNA expression were significantly correlated with each other in mammary epithelial cells (p<0.01). All cows produced either less than 30 kg/day/cow or a over 30 kg/day/cow level of milk yield (MY). It was shown that the CN mRNA expression levels decreased gradually from the calving period to late lactation, when MY was over 30 kg/day/cow. The SCC tended to increase gradually during the course of lactation, but it was negatively correlated with milk protein and CN yields (p<0.01) when MY was less than 30 kg/day/cow. Moreover, there was a tendency for a negative correlation between SCC and ${\alpha}s1$-CN and ${\beta}$-CN mRNA expression level, when MY was less than 30 kg/day/cow (p<0.05).

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.2
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• pp.257-264
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• 2019

Objective: Dairy cattle nutrient requirement systems acknowledge amino acid (AAs) requirements in aggregate as metabolizable protein (MP) and assume fixed efficiencies of MP used for milk protein. Regulation of mammary protein synthesis may be associated with AA input and milk protein output. The aim of this study was to evaluate the effect of nanoemulsified methionine and cysteine on the in-vitro expression of milk protein (casein) in bovine mammary epithelial cells (MAC-T cells). Methods: Methionine and cysteine were nonionized using Lipoid S 75 by high-speed homogenizer. The nanoemulsified AA particle size and polydispersity index were determined by dynamic light scattering correlation spectroscopy using a high-performance particle sizer instrument. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the cytotoxicity effect of AAs with and without nanoionization at various concentrations (100 to $500{\mu}g/mL$) in mammary epithelial cells. MAC-T cells were subjected to 100% of free AA and nanoemulsified AA concentration in Dulbecco's modified Eagle medium/nutrient mixture F-12 (DMEM/F12) for the analysis of milk protein (casein) expression by the quantitative reverse transcription polymerase chain reaction method. Results: The AA-treated cells showed that cell viability tended to decrease (80%) in proportion to the concentration before nanogenesis, but cell viability increased as much as 90% after nanogenesis. The analysis of the expression of genetic markers related to milk protein indicated that; ${\alpha}_{s2}$-casein increased 2-fold, ${\kappa}$-casein increased 5-fold, and the amount of unchanged ${\beta}$-casein expression was nearly doubled in the nanoemulsified methionine-treated group when compared with the free-nanoemulsified methionine-supplemented group. On the contrary, the non-emulsified cysteine-administered group showed higher expression of genetic markers related to milk protein ${\alpha}_{s2}$-casein, ${\kappa}$-casein, and ${\beta}$-casein, but all the genetic markers related to milk protein decreased significantly after nanoemulsification. Conclusion: Detailed knowledge of factors, such nanogenesis of methionine, associated with increasing cysteine and decreasing production of genetic markers related to milk protein (casein) will help guide future recommendations to producers for maximizing milk yield with a high level of milk protein casein.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.5
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• pp.738-742
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• 2003

The monitoring was carried out for one year on 20 farms of Mediterranean buffalo situated in central Italy. The milk yield, the somatic cell count, the coagulating properties and some components were determined. The average value of somatic cells was $21.28n{\times}10^3/ml$. Milk production decreased when somatic cell numbers increased. The rennet clotting time increased significantly when somatic cells were higher than $300.00n{\times}10^3/ml$, the curd firming time was significantly higher when somatic cells were more than $1,000.00n{\times}10^3/ml$ and the curd firmness increased up to $200.00n{\times}10^3$/ml, then gradually decreased. Protein and casein decreased when somatic cells increased and the same trend was shown by casein/protein ratio. Both for these components and the coagulating properties the threshold limit of somatic cells to obtain better results was $200.00n{\times}10^3/ml$. The somatic cell number did not show a trend which was strictly influenced by the lactation stage, contrary to what happened in the other species.

• Journal of Microbiology and Biotechnology
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• v.21 no.8
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• pp.869-873
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• 2011

Most medium formulations for improving culture of entomopathogenic nematodes (EPN) based on protein sources have used enriched media like animal feed such as dried egg yolk, lactalbumin, and liver extract, among other ingredients. Most results, however, showed unstable yields and longer production time. Many of the results do not show the detailed parameters of fermentation. Soy flour, cotton seed flour, corn gluten meal, casein powder, soytone, peptone, casein hydrolysates, and lactalbumin hydrolysate as protein sources were tested to determine the source to support optimal symbiotic bacteria and nematode growth. The protein hydrolysates selected did not improve bacterial cell mass compared with the yeast extract control, but soy flour was the best, showing 75.1% recovery and producing more bacterial cell number ($1.4{\times}10^9$/ml) than all other sources. The highest yield ($1.85{\times}10^5$ IJs/ml), yield coefficient ($1.67{\times}10^6$ IJs/g medium), and productivity ($1.32{\times}10^7$ IJs/l/day) were also achieved at enriched medium with soybean protein.

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