713. The relation between the chemical composition of milk and the stability of the caseinate complex: II. Coagulation by ethanol

1958 ◽  
Vol 25 (2) ◽  
pp. 256-266 ◽  
Author(s):  
D. T. Davies ◽  
J. C. D. White
Keyword(s):  
Chemical Composition ◽  
Milk Protein ◽  
Aqueous Ethanol ◽  
Subclinical Mastitis ◽  
Milk Composition ◽  
Ionized Calcium ◽  
Bulk Milk ◽  
The Stability ◽  
The Relationship ◽  
Ethanol Stability

1. The variation in the stability of milk protein to ethanol and the relationship between milk composition and ethanol stability were examined.2. Samples of herd bulk milk were very similar in stability to ethanol; the range of aqueous ethanol solutions required to coagulate the caseinate complex in an equal volume of milk was only 80–84% (v/v) ethanol. Samples from individual cows showed a wide variation in stability; coagulation was caused by ethanol solutions ranging in strength from 66 to 90% (v/v) ethanol.3. Colostrum was very unstable to ethanol but stability rapidly increased during the post-colostrum period to higher levels in mid-lactation. Late lactation and subclinical mastitis milk showed no definite bias towards stability or instability.4. The strength of ethanol required to coagulate the caseinate complex in an equal volume of milk was inversely related to the concentration of ionized calcium in the milk. The correlation coefficient was –0·76 (significant at 0·001 level) indicating that approximately 60% of the variation in stability was accounted for by the variation in the concentration of ionized calcium.5. The relationships between the concentrations of other milk constituents and stability to ethanol could be attributed to the interrelations of the concentrations of these constituents and the concentration of ionized calcium.

715. The relation between the chemical composition of milk and the stability of the caseinate complex: IV. Coagulation by heat

1958 ◽  
Vol 25 (2) ◽  
pp. 281-296 ◽  
Author(s):  
J. C. D. White ◽  
D. T. Davies
Keyword(s):  
Calcium Phosphate ◽  
Milk Protein ◽  
Heat Stability ◽  
Milk Composition ◽  
Ionized Calcium ◽  
Coagulation Time ◽  
Complex Iv ◽  
Stage Of Lactation ◽  
The Stability ◽  
The Relationship

1. The variation in the stability of milk protein to heat and the relationship between milk composition and heat stability were examined.2. The coagulation times of the majority of the milk samples decreased by a factor of about 3 with an increase in temperature of 10°C. over the range 130–150°C. Because of the general proportionality of the coagulation times at 130, 140 and 150°C., the coagulation time at 130°C. only were used as a measure of the stability of the samples to heat.3. The coagulation times of herd bulk milks ranged from 17·2 to 59·0 min. at 130°C., whereas the range for samples from individual cows was 0·6–86·2 min.4. Samples of colostrum were very unstable to heat, and milk from cows in late lactation tended to have the longest coagulation times, but otherwise there was little relation between the heat stability of milk and the stage of lactation of the cow.5. Although colostrum samples were comparatively rich in ionized calcium, their marked instability to heat appeared to be caused solely by their high content of lactalbumin plus lactoglobulin.6. The stability to heat of the calcium caseinate-calcium phosphate complex in all samples, other than colostrum, could not be closely related either to the concentration and composition of the complex or to the composition and salt-balance of the aqueous phase.7. When the calcium phosphate content of the caseinate complex was relatively low, the heat stability of the complex tended to be inversely related to the concentration of ionized calcium in the milk, but in general coagulation time was not related to the concentration of ionized calcium.

712. The relation between the chemical composition of milk and the stability of the caseinate complex: I. General introduction, description of samples, methods and chemical composition of samples

1958 ◽  
Vol 25 (2) ◽  
pp. 236-255 ◽  
Author(s):  
J. C. D. White ◽  
D. T. Davies
Keyword(s):  
Chemical Composition ◽  
Technical Assistance ◽  
Subclinical Mastitis ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Cell Counts ◽  
Bulk Milk ◽  
Agricultural College ◽  
The Stability ◽  
Detailed Chemical

1. This paper is Part I of a series dealing with the relation between the chemical composition of milk and the stability of the caseinate complex to ethanol (Part II), rennet (Part III) and heat (Part IV).2. A description is given of the milk samples, which were taken from herd bulk milk, from individual cows in different stages of lactation and also from cows with subclinical mastitis.3. The methods used to measure the stability of the caseinate complex to the three coagulating agents are described, together with the methods used to make a detailed chemical analysis of the milk samples.4. The chemical composition of the samples is given and also the relation between composition and stage of lactation, and the interrelations of the concentrations of certain milk constituents.The authors thank Miss M. H. King and Miss R. E. M. Stevenson for technical assistance, Mr N. H. Strachan and Mr R. C. Voss (West of Scotland Agricultural College) for the sodium and potassium determinations and Dr P. S. Blackburn for the differential cell counts and bacteriological examination of the milks.

scholarly journals Chemical Composition of Milk and Rumen Microbiome Diversity of Yak, Impacting by Herbage Grown at Different Phenological Periods on the Qinghai-Tibet Plateau

Animals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1030 ◽  
Author(s):  
Qingshan Fan ◽  
Metha Wanapat ◽  
Fujiang Hou
Keyword(s):  
Chemical Composition ◽  
Milk Protein ◽  
Chemical Constituents ◽  
Milk Composition ◽  
Tibet Plateau ◽  
Ruminal Fermentation ◽  
Yak Milk ◽  
Milk Protein Content ◽  
Fermentation Parameters ◽  
Qinghai Tibet Plateau

To estimate how native herbage of three different phenological periods modify rumen performance and milk quality of yak grazing alpine meadow. In this study, milk composition and the diversity of the rumen microbial community were measured in 12 full-grazing female yaks on the Qinghai-Tibet Plateau (QTP). The nutrient composition of three phenological periods was determined: Vegetative stage (VS), bloom stage (BS), and senescent stage (SS). High-throughput sequencing of the bacterial 16S rRNA gene was used. The results showed that crude protein (CP) content of herbage in BS was higher than that in vs. and SS (p < 0.05), and neutral detergent fiber (NDF) content of herbage in SS was higher than that in vs. and BS (p < 0.05). Milk solids and fat contents were higher in the vs. and SS than in BS (p < 0.05). However, milk protein content was higher for the vs. and BS than those for SS (p < 0.05). The total volatile fatty acid (VFA), acetate, and propionate concentrations were higher in vs. and BS than in SS (p < 0.05). The community richness estimates (Chao1 estimator) of vs. were higher than that in BS and the SS (p < 0.05). The diversity indices (Shannon index) of the BS were higher than that vs. and the SS (p < 0.05). Spearman correlation analysis between the milk composition, ruminal fermentation parameters, and the relative abundances of the rumen bacteria showed that milk protein content, total VFA, acetate, and propionate concentrations were positively correlated with the relative abundances of the genera Desulfovibrio, Prevotella_1, and Butyrivibrio_2 and was negatively correlated with Olsenella, Ruminococcaceae_UCG.010, and Rikenellaceae_RC9_gut_group abundances. Collectively, the results revealed that there were significant differences in nutrient composition of herbage, chemical composition of yak milk, and microbial diversity in rumen at different phenological stages. The correlations between ruminal fermentation parameters, chemical constituents of yak milk, and some genera of ruminal bacteria might be indicative that the ruminal fermentation parameters and chemical constituents of yak milk are strongly influenced by the rumen bacterial community composition.

The relationship between milk yield, composition and tissue damage in a case of subclinical mastitis

1963 ◽  
Vol 30 (1) ◽  
pp. 23-33 ◽  
Author(s):  
R. Waite ◽  
P. S. Blackburn
Keyword(s):  
Chemical Composition ◽  
Milk Yield ◽  
Tissue Damage ◽  
Subclinical Mastitis ◽  
Bacteriological Examination ◽  
Cell Content ◽  
Upper Level ◽  
The Relationship ◽  
Number Of Cells

SummaryA chemical, cytological and bacteriological examination of the milk from each quarter of a cow suffering from subclinical mastitis, but giving 5–6 gal of milk per day, was made at weekly intervals during the first 84 days after parturition. The infection, caused by micrococcal and staphylococcal bacteria, resisted repeated treatments with various antibiotics administered via the teat canals and also intramuscularly, although in vitro the bacteria were susceptible to all the antibiotics used. The cow was slaughtered and a histological examination made of the udder in an attempt to establish the cause of the continuing infection and to assess the extent of tissue damage. Two quarters each contained large abscesses in the upper level of the udder and these could have acted as reservoirs of infection; no cause was established for the other two quarters and it can only be assumed that reinfection occurred from the two abscessed quarters.The amount of active lesions in the lobules of all the quarters was small, 1–6%, but half or more of all the lobules were involuted, although only a minority appeared to have involuted as a result of infection. In the two abscessed quarters there was extensive damage to the duct system, 23 and 31% showing lesions.When the milk contained an abnormally large number of cells the chemical composition was also abnormal, containing less lactose (and hence less solids-not-fat) and having a nitrogen distribution in which there was more blood serum albumin and globulin and less casein than usual. Cell content and chemical composition were better indicators of tissue damage than the presence of mastitis organisms. It is estimated that the solids-not-fat content of the milk of the whole udder as a result of the infections was considerably lower than it would otherwise have been (8·0 instead of 8·8%) and that the daily loss in milk yield was about 9 lb.

scholarly journals The trend of cowmilk yield, its compostion and the body condition during the lactation

2009 ◽  
pp. 69-73
Author(s):  
Edit Mikó Józsefné Jónás ◽  
Imre Mucsi ◽  
István Komlósi
Keyword(s):  
Dairy Cows ◽  
Body Condition ◽  
Milk Fat ◽  
Milk Protein ◽  
Milk Composition ◽  
Fat Content ◽  
The Body ◽  
Significant Difference ◽  
The Relationship ◽  
Body Condition Scores

The authors examined the data of 2767 trial milkings andthe months Body Condition Scores of 479 Holstein dairy cows. The condition loss was significant between the 30-60th days. The improvement of BCS begins only after the 120th day. The change in the milk protein and milk fat content were close after the condition changing. In each period of the lactation the closeness of the relationship among the condition, the milk quantity and the milk composition were different. In the aspect of the milk quantity the most significant difference was between the 2.5 and 4 BCS cows (6.68 kg) in the last period of the lactation.

scholarly journals Chemical and functional properties of different common Brazilian bean (Phaseolus vulgaris L.) cultivars

2017 ◽  
Vol 20 (0) ◽  
Author(s):  
Milene Marquezi ◽  
Vanessa Maria Gervin ◽  
Lucas Bertoldi Watanabe ◽  
Rodolfo Moresco ◽  
Edna Regina Amante
Keyword(s):  
Chemical Composition ◽  
Functional Properties ◽  
Principal Component ◽  
Emulsifying Properties ◽  
Phaseolus Vulgaris L ◽  
Bean Cultivar ◽  
Foaming Capacity ◽  
The Stability ◽  
Emulsifying Capacity ◽  
The Relationship

Abstract Six different common bean cultivars (BRS Embaixador, BRS Pitanga, BRS Estilo, Pérola, BRS Campeiro and BRS Esplendor) were characterized aiming to determine possible uses for them in various food products. The samples were analysed to determine their chemical composition, weight per hundred beans, pH, water and oil absorption capacities (WAC and OAC, respectively), foaming at pH 2.5, 5.6 and 8.0 and emulsifying properties. The relationship between the physicochemical and functional properties was described using the Principal Component Analysis (PCA). The results of the chemical composition, weight per hundred beans, WAC and OAC showed differences even between cultivars of the same commercial group. Foaming also varied between the cultivars and foaming capacity and stability were greatest at pH 5.6 and 8.0. The emulsifying capacity proved quite high for all cultivars, as well as the stability of the emulsion. According to these properties, with the contribution of the PCA, each different bean cultivar can be destined to specific applications according to its physicochemical properties.

The stability of milk protein to heat: II. Effect on heat stability of ageing milk at different temperatures

1966 ◽  
Vol 33 (1) ◽  
pp. 83-91 ◽  
Author(s):  
D. T. Davies ◽  
J. C. D. White
Keyword(s):  
Milk Protein ◽  
Heat Stability ◽  
Subclinical Mastitis ◽  
Progressive Increase ◽  
Common Occurrence ◽  
Coagulation Time ◽  
Rate Of Increase ◽  
Different Temperatures ◽  
Significant Change ◽  
The Stability

SummaryThe effect on heat stability as measured by coagulation time, of storing separated milk at 20, 4 and −20 °C has been examined. Milk with a good coagulation (initial clots large) could be stored for at least 30 h at 20 °C, 1 week at 4 °C and 1 month at −20 °C with no significant change in coagulation time. With milks giving a poor coagulation (initial clots small), a common occurrence during storage at 20 °C was a marked progressive increase in coagulation time; the rate of increase was reduced by storage at 4 °C. The increase in coagulation time of these labile milks, which are usually obtained from cows with subclinical mastitis, may occur to the same extent in darkness as in light, may be enhanced by exposure to light or may occur only when the milk is exposed to light. From these results, together with others reported by Davies & White (1966) and White & Davies (1966) it is concluded that, in studying heat stability, milks giving a good coagulation should be regarded as in a different class from milks giving a poor coagulation.

scholarly journals Fractionized milk composition in dairy cows with subclinical mastitis

2012 ◽  
Vol 49 (No. 8) ◽  
pp. 283-290 ◽  
Author(s):  
R. M Bruckmaier ◽  
C. E Ontsouka ◽  
J. W Blum
Keyword(s):  
Electrical Conductivity ◽  
Subclinical Mastitis ◽  
Milk Composition ◽  
Milk Traits ◽  
Sodium Potassium ◽  
Cell Counts ◽  
Group I ◽  
Group Ii ◽  
The Relationship ◽  
Necrosis Factor

Mastitis is the inflammatory reaction of the udder to invading pathogens. One of the most apparent reactions is the increased influx of immunoreactive cells from blood into milk inducing a dramatic increase of milk somatic cell counts (SCC). We have investigated (i) the relationship between log SCC/ml in infected quarters being&nbsp;&gt;6 (n = 8, group I) or varying between 5.4 and 6 (n = 8, group II) and concentration of dry matter (DM), fat, protein, lactose, insulin-like growth factor (IGF)-1, insulin, prolactin, tumor necrosis factor (TNF)-, sodium, potassium, chloride, electrical conductivity and osmolarity as compared with the contralateral (healthy) quarter (log SCC/ml &lt;5.2); and (ii) composition of fractionized milk [cisternal milk, quartiles of alveolar milk and residual milk (after i.v. injection of 10 u.i. oxytocin)] during machine milking of infected and healthy quarters. SCC were higher (P &lt;&nbsp;0.05) in infected than in healthy quarters. Concentrations of fat, sodium, chloride, and IGF-1 were higher (P &lt; 0.05), while that of lactose was lower (P &lt; 0.05) in infected than in healthy quarters (group I). Concentrations of fat and chloride in both groups, of DM (in group II), and electrical conductivity and sodium (in group I) increased from the cisternal to alveolar (100%) fractions in infected quarters, while fat and DM concentrations similarly increased in healthy quarters. In conclusion, several but not all milk traits changed in a different manner during the course of milking in infected and non-infected quarters.

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