A comparison of the hydrometric and gravimetric methods for the determination of solids-not-fat when applied to the milk of individual cows in a single herd

1961 ◽  
Vol 28 (2) ◽  
pp. 109-115 ◽  
Author(s):  
R. A. Edwards
Keyword(s):  
Protein Content ◽  
Correction Factor ◽  
Gravimetric Method ◽  
Cow Milk ◽  
Total Solids ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Solids Content ◽  
Main Factor

SummaryFive hundred and sixty-nine individual cow milk samples from forty-five cows in a single herd were analyzed for fat by the Gerber method, and solids-not-fat by a standard gravimetric method and by the two commonly used British hydrometric techniques. Three hundred and four of the samples were analyzed also for lactose, protein and ash. Large differences between the total solids values obtained by the hydrometric and gravimetric methods were recorded. The magnitude of the differences from the gravimetric values varied with the season of the year and the stage of lactation. The main factor affecting the differences was the protein content of the milk, and equations for the calculation of total solids content incorporating a protein correction factor are given for use if the protein content be known. The hydrometric methods are considered to be of limited use when applied to milks of individual cows.

scholarly journals Assessment of dairy cow energy status using milk fat, protein and urea concentrations

2012 ◽  
Vol 66 (1-2) ◽  
pp. 97-110
Author(s):  
Danijela Kirovski ◽  
Horea Samanc ◽  
Radisa Prodanovic
Keyword(s):  
Protein Content ◽  
Milk Sample ◽  
Urea Concentration ◽  
Cow Milk ◽  
Energy Status ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Milk Components ◽  
Physiological Values ◽  
The Individual

One of the ways to make an assessment of the energy status of cows in lactation is to consider the results obtained from the evaluation of the concentrations of organic milk components. The advantages of this method are that the taking of milk samples is not stressful for the cow and that it is also possible to use the results of milk examinations carried out by dairy plants within regular control. A bulk milk sample from all individual cows can be used, or an individual milk sample. In farms that have herds of unequal genetic potential, it is preferable to assess the energy status by analyzing the results for individual samples, because each animals is assessed individually in that way. Furthermore, the use of individual milk samples is recommended at newly-established farms in order to facilitate the establishment of reference values for the herd. The energy status of cows is assessed using the milk samples by analyzing fat, protein and urea concentrations and their mutual ratios. Fat and protein concentrations in cow milk vary depending on the breed, the diet, age, stage of lactation, and the season of the year. A fat content lower than the physiological values can be expected in cases of unfavourable diet of the cows during the period around calving or rumen acidosis, and it can be expected to be higher during ketotic conditions. A higher protein content in milk can be expected during a high-protein, and a lower one during a low-protein diet of the cows. The physiological concentration of urea in milk depends on nutritive factors, the season, age, stage of lactation, and body mass. Specifically, older cows, cows in advanced lactation, and cows in the summer period tend to have higher values for urea concentration in milk. Among nutritive factors, the most important is the ratio between energy and proteins in the cow feed ration. In cases when protein content in milk is optimal or above the recommended values but the energy supply is lower, the urea concentration increases to over the range of physiological values. In the event that the feed ration is deficient in both proteins and energy the urea content in milk drops. This work also presents a model for assessing the energy status in cows by analyzing the mutual ratios between the individual milk components (proteins and fat, or urea and proteins) in the individual milk samples. It is possible to determine the energy status of the animal on the basis of the ratio between proteins and fat, and the supply of the cow with proteins and energy on the basis of the ratio between urea and proteins.

scholarly journals The chemical composition and technological properties of milk obtained from the morning and evening milking

2008 ◽  
Vol 56 (5) ◽  
pp. 187-198 ◽  
Author(s):  
Martin Skýpala ◽  
Gustav Chládek
Keyword(s):  
Protein Content ◽  
Milk Yield ◽  
Milk Fat ◽  
Protein Production ◽  
Milk Protein ◽  
Fat Content ◽  
Total Solids ◽  
Milk Protein Content ◽  
Solids Content ◽  
Morning Milk

Milk yield varies during lactation, following what is termed a lactation curve. ŽIŽLAVSKÝ and MIKŠÍK (1988) recorded changes in milk yield within a day, too. TEPLÝ et al. (1979) a KOUŘIMSKÁ et al. (2007) published variation within a day ± 1.10 kg in milk yield, ± 0.75 % in milk fat content and ± 0.20 % in milk protein content. Milk yield of cows can be expressed in many different ways, for instance, in kilograms per lactation or in kilograms per day. A practical parameter describing milk production is milk yield (kg) per milking.The object of experiment were 12 cows of Holstein cattle on the first lactation from the 100-day of lactation to 200-day of lactation. The samples of milk were collected from January to May 2007, once a month from the morning and evening milking (milking interval 12 h ± 15 min.). The following parameters were monitored: milk production – milk yield (kg), milk protein production (kg), milk fat production (kg); milk composition – milk protein content (%), milk fat content (%), lactose content (%), milk solids-not-fat content (%), milk total solids content (%); technological properties of milk – ti­tra­tab­le acidity (SH), active acidity (pH), rennet coagulation time (s), quality of curd (class) and somatic cell count as a parameter of udder health.Highly significant differences were found (P < 0.01) between morning milk yield (15.7 kg) and evening milk yield (13.8 kg), between morning milk protein production (0.51 kg) and evening milk protein production (0.45 kg) and between evening milk fat content (4.41 %) and morning milk fat content (3.95 %). A significant difference (P < 0.05) was found between morning milk total solids content (12.62 %) and evening milk total solids content (12.07 %). No significant differences were found between morning (M) and evening (E) values of the remaining parameters: milk fat production (M 0.62 kg; E 0.60 kg), milk protein content (M 3.24 %; E 3.27 %), milk lactose content (M 4.78 %; E 4.86 %), milk solids-not-fat content (M 7.69 %; E 7.71 %), somatic cell count (M 80 000/1 mL; E 101 000/1 mL), titratable aci­di­ty (M 7.75 SH; E 7.64 SH), active acidity (M pH 6.58; E pH 6.61), rennet coagulation time (M 189 s.; E 191 s.), quality of curd (M 1.60 class; E 1.57 class).

scholarly journals Evaluation of some chemical parameters of powder milk available in Mymensingh town

2012 ◽  
Vol 10 (1) ◽  
pp. 95-100 ◽  
Author(s):  
M F I Kajal ◽  
A Wadud ◽  
M N Islam ◽  
P K Sarma
Keyword(s):  
Statistical Analysis ◽  
Significant Variation ◽  
Milk Powder ◽  
Cow Milk ◽  
Local Market ◽  
Chemical Parameters ◽  
Total Solids ◽  
Milk Samples ◽  
Powder Milk ◽  
Powder Samples

The study was undertaken to evaluate some chemical parameters of powder milk available in Mymensingh town. Powder milk samples of six different brands namely Kwality, NIDO, Diploma, Anchor, Farmland & Starship were collected from local market. Powder samples were analyzed to know the chemical (PH, acidity, fat, protein, lactose, ash, moisture, solids-not-fat, total solids) characteristics. PH, acidity of all samples was almost similar to the cow milk  when the dried milk was reconstituted. PH ranged from 6.6-6.8, acidity from 0.10-0.15, fat from 26.198-27.89 g/100 g,  protein from 25.22-27.01 g/100g, lactose from 36.63-37.65 g/100g, ash from 5.34-5.48 g/100g, moisture from 3.36-4.48 g/100g, solids-not-fat from 67.99-70.07 g/100g, total solids from 95.51-96.63 g/100g, among the brands of powder milk. Statistical analysis showed significant variation for (PH and acidity) among different powder milk brands. chemical parameters in all brands of milk powder was found as per recommended standard. DOI: http://dx.doi.org/10.3329/jbau.v10i1.12099 J. Bangladesh Agril. Univ. 10(1): 95–100, 2012    

scholarly journals Analysis of Fat and Protein Content in Milk Using Laser Polarimetric Scatterometry

Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1028
Author(s):  
Alexey V. Shkirin ◽  
Dmitry N. Ignatenko ◽  
Sergey N. Chirikov ◽  
Nikolai F. Bunkin ◽  
Maxim E. Astashev ◽  
...  
Keyword(s):  
Protein Content ◽  
Dairy Production ◽  
Size Distributions ◽  
Fat Percentage ◽  
Milk Samples ◽  
Quantitative Content ◽  
Scattering Matrices ◽  
Control Milk ◽  
Dairy Cow Nutrition

Monitoring the composition of milk products is an important factor in the management of dairy farms and industry. Information on the quantitative content of milk components is necessary to control milk quality, as well as to optimize dairy cow nutrition and diagnose their clinical condition. The content of fat and protein is considered the main criterion for determining the market value of milk. Increasing the efficiency of dairy production requires the use of inexpensive and compact devices that are capable of performing multicomponent analysis of milk both directly on the farm and in technological lines. We investigated the possibility of fast simultaneous determination of fat and protein content in milk by laser polarimetric scatterometry. The block-diagonal elements of the scattering matrix were measured for a series of commercially produced milk samples with the indicated fat percentage, which were diluted by volume with water. From the measured scattering matrices, the size distributions of fat droplets and casein aggregates were reconstructed. Using the size histograms, the content of fat and protein and protein-to-fat ratio in the studied milk samples are estimated.

scholarly journals Evaluation of the quality of Dahi available in Sylhet Metropolitan City

1970 ◽  
Vol 9 (1) ◽  
pp. 79-84 ◽  
Author(s):  
S Dey ◽  
A Iqbal ◽  
A Ara ◽  
MH Rashid
Keyword(s):  
Protein Content ◽  
Viable Count ◽  
Coliform Bacteria ◽  
Microbial Count ◽  
Total Viable Count ◽  
Total Solids ◽  
Metropolitan City ◽  
Significant Difference ◽  
Solids Content

The study was undertaken to evaluate the quality of Dahi available in Sylhet Metropolitan City. Dahi samples from five different Sweetmeat Shops namely Fulkoli, Banaful, Mohanlal, Modhuban and Shad were collected and analyzed. Significant difference in chemical (protein, fat, total solids, ash, acidity and pH) and microbiological status was found among different Dahi samples. Of the five Dahi Brands examined, Fulkoli Brand Dhai had the highest protein content (4.58 ± 0.24) and Shad Brand Dahi had the lowest protein content (4.01 ± 0.17). Fat content was highest in Fulkoli Brand (4.02 ± 0.13) and lowest in Shad Brand (2.10 ± 0.21). The highest total solids content was found in Dahi of Shad Brand (38.00 ± 2.23) and lowest total solids content was found in Banaful Brand Dahi (32.02 ±1.50). Highest Total Viable Count (log cfu/ml.) was recorded in the Dahi of Shad Brand (5.92±0.09) and lowest Total Viable Count was recorded in Mohanlal Brand Dahi (5.84±0.06). Coliform bacteria, Yeast and Mould were present in all the samples. From this experiment, it was found that Fulkoli Brand Dahi was the best in quality . Dahi of Banaful and Mohanlal were in 2nd and 3rd position in quality. Keywords: Fermented milk; Evaluation; Chemical analysis; Microbial count; Total viable count DOI: http://dx.doi.org/10.3329/jbau.v9i1.8748 JBAU 2011; 9(1): 79-83

scholarly journals Whey pretreatments before ultrafiltration

1994 ◽  
Vol 3 (5) ◽  
pp. 473-479
Author(s):  
Tuomo Tupasela ◽  
Heikki Koskinen ◽  
Pirkko Antila
Keyword(s):  
Protein Content ◽  
Dry Matter ◽  
Whey Proteins ◽  
Ph Adjustment ◽  
Total Solids ◽  
Heat Treated ◽  
Protein Membrane ◽  
Membrane Isolation ◽  
Solids Content ◽  
Β Lactoglobulin

Whey is a by-product of cheesemaking. Whey dry matter contains mainly lactose, but also valuable whey proteins. The aim of this study was to develop improvements to whey protein membrane isolation processes. In our trials CaCl2 -added, pH-adjusted and heat-treated wheys were found to have MF (microfiltration) permeate fluxes about 30% higher than in untreated MF whey. The total solids and protein content of the MF permeates decreased compared to the original wheys. UF (ultrafiltration) trials were conducted using MF whey to compare it with centrifugally separated whey. The MF whey consistently maintained an UF flux about 1.5 to 2.5 times higher than that of the separated whey. Differently treated MF whey UF permeate fluxes also showed a difference. With CaCl2 addition, pH adjustment and heat treatment, the UF permeate fluxes were about 20 to 40% higher than when only MF was used. The total solids content decreased in each trial. The protein content of the UF concentrate also decreased compared to the MF permeate. The (β-lg (β-lactoglobulin) and α-la (α-lactalbumin) content was almost the same in UF concentrates as in MF permeates.

scholarly journals Determination of Ultratrace Bismuth in Milk Samples by Atomic Fluorescence Spectrometry

2003 ◽  
Vol 86 (4) ◽  
pp. 815-822 ◽  
Author(s):  
Patricia Cava-Montesinos ◽  
M Luisa Cervera ◽  
Agustín Pastor ◽  
Miguel de la Guardia
Keyword(s):  
Inductively Coupled Plasma ◽  
Limit Of Detection ◽  
Hydride Generation ◽  
Fluorescence Spectrometry ◽  
Cow Milk ◽  
Atomic Fluorescence Spectrometry ◽  
Atomic Fluorescence ◽  
Microwave Assisted ◽  
Milk Samples

Abstract A sensitive procedure was developed for determination of bismuth (Bi) in milk samples by hydride generation atomic fluorescence spectrometry (HG–AFS) after microwave-assisted sample digestion with HNO3 and H2O2. The method provides a sensitivity of 1832 fluorescence units (ng/mL) with a detection limit of 0.01 ng/mL, which corresponds to 20 pg absolute limit of detection, equivalent to 0.50 ng/g in the original sample. Application of the methodology to cow milk samples from the Spanish market showed the presence of Bi at a concentration of 11.8–28.8 ng/g, which compared well with data obtained after dry ashing of samples and with data obtained by inductively coupled plasma–mass spectrometry after microwave-assisted digestion.

Evaluation of Automated Dye Binding Determination of Protein in Milk

1974 ◽  
Vol 57 (1) ◽  
pp. 42-47
Author(s):  
Douglas L Park ◽  
Raymond L King
Keyword(s):  
Protein Content ◽  
Mercuric Chloride ◽  
Sampling Rate ◽  
Protein Determination ◽  
Binding System ◽  
Milk Samples ◽  
Instrument Performance ◽  
Dye Binding ◽  
Herd Milk

Abstract The Technicon AutoAnalyzer dye binding system for protein determination in milk was compared with the Kjeldahl and Udy methods. Individual cow and mixed herd milk samples were analyzed, including such variables as the effect of aging, chemical preservation, laboratory manipulation of protein content, and experimental changes in instrumental parameters. The Udy and Kjeldahl methods showed better agreement than the Technicon procedure in all treatments. Aging resulted in slight decreases in apparent protein content by both dye binding methods. Variation due to treatment with formaldehyde and mercuric chloride was considerable for the Technicon system (+ 0.72 and +0.20% protein, respectively). Individual cow milks varied more than herd milks and Guernsey more than Holstein milk. Milk samples standardized for protein content showed a high correlation with the Kjeldahl results. Replication by the Technicon system was superior to both the Udy and Kjeldahl methods. Performance of the Technicon system improved with increased dialyzing time, decreased dye concentration, and decreased sampling rate. Instrument performance was also influenced by dialysis membrance replacement.

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