Physical properties of mammary secretions in relation to chemical changes during transition from colostrum to milk

2004 ◽  
Vol 71 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Birgitte D Madsen ◽  
Morten D Rasmussen ◽  
Mette O Nielsen ◽  
Lars Wiking ◽  
Lotte B Larsen
Keyword(s):  
Physical Properties ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Potential Method ◽  
Early Lactation ◽  
Coagulation Time ◽  
Chemical Changes ◽  
Milk Samples ◽  
Rennet Coagulation ◽  
Physical And Chemical

We examined the physical and chemical changes in milk during early lactation, and how these changes were affected by leaving one quarter unmilked in either the first or second milking, with the purpose of discriminating between colostrum and normal milk. Milk samples were collected from each quarter of 17 cows during the first 5 d after calving and then after about 7 d and 14 d. Samples were analysed for somatic cell count (SCC), fat, protein, casein, lactose, IgG1, colour, plasmin, pH and coagulation properties. Large variations occurred in both chemical and physical properties throughout the study period. Within six milkings, the concentration of casein decreased by 60%, IgG1 by 94%, and lactose increased by 34%. At milking number 6, rennet coagulation time was lowest and curd firmness was highest. The pH increased from 6·4 to 6·7 over the period of the experiment, and the colour changed from yellow (reddish) to white. Coagulation properties and the pH fell within the range of normal milk after five milkings. Measurement of colour and density appeared to be a potential method for detection of milk unsuitable for the dairy factory. Effects of omitting one quarter in one milking differed between milk components, but seemed to be of little importance to the physical properties.

Composition and processability of bovine milk from herds with different calving patterns

2000 ◽  
Vol 25 ◽  
pp. 77-86 ◽  
Author(s):  
B. O’Brien
Keyword(s):  
Total Protein ◽  
Somatic Cell Count ◽  
Bovine Milk ◽  
Experimental Period ◽  
Early Lactation ◽  
Milk Supply ◽  
Coagulation Time ◽  
Rennet Coagulation ◽  
Product Manufacture ◽  
Continuous Product

AbstractThe chemical composition and processing characteristics of milks from spring and autumn calving herds were investigated to establish if an autumn/winter milk supply would overcome the variation in composition and quality which is characteristic of a seasonal milk supply. Three herds of 26 cows were established with mean calving dates of 22 February, 28 September and a 50:50 combination of both. The experimental period was from 5 August to 22 December. Bulk milks were collected separately from each of the three herds at one consecutive am and pm milking each week. Spring and autumn milks were also bulked in proportions of 70:30, 50:50 and 30:70, respectively. All milks were analysed for gross composition, protein fractions, renneting properties (rennet coagulation time [RCT], rate of curd aggregation [K20] and curd firmness [A60]), free fatty acids (FFA) and somatic cell count (SCC). Total protein and casein of spring milk were reduced (P<0.001) from 38.1 and 28.7 g/kg, respectively in the period 14 October-24 November to 33.8 and 25.9 g/kg in the period 25 November-22 December. This was accompanied by a deterioration (minimum P<0.01) in RCT from 21.7 to 33.3 min, in K20 from 8.2 to 15.2 min and in A60 from 43.8 to 30.8 mm. Autumn milk had higher fat (P<0.01) and lactose (P<0.001) concentrations, lower FFA levels (P<0.001), improved (P<0.001) RCT, K20 and A60 values compared to spring milk in the period 25 November-22 December. During this period, the 70:30 milk had improved RCT (P<0.01) and K20 (P<0.05) values and reduced (P<0.01) FFA levels compared to spring milk. It is concluded that the composition and processing characteristics of spring milk deteriorated after 275 days in milk. Changes in total protein and casein were closely associated with changes in renneting properties. Blending of autumn milk with spring milk improved the processing characteristics of the mix compared to those of spring milk. Thus, the introduction of early lactation autumn milk at the end of the spring lactation would maintain good milk processability and allow continuous product manufacture.

Heterogeneity of proteolytic enzyme activities in milk samples of different somatic cell count

2003 ◽  
Vol 70 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Joanne M Somers ◽  
Bernadette O'Brien ◽  
William J Meaney ◽  
Alan L Kelly
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Cathepsin D ◽  
Proteolytic Enzyme ◽  
Somatic Cell Count ◽  
Proteolytic Enzymes ◽  
Physical Stability ◽  
Raw Milk ◽  
Milk Samples ◽  
Rennet Coagulation

Milk contains the alkaline proteinase plasmin and lysosomal proteinases; the significance of the latter is ill-defined. The objective of this study was to investigate composition and activities of several different proteolytic enzymes in milk samples of varying somatic cell count (SCC). Increasing milk SCC was correlated with increased plasmin, cathepsin D and cysteine protease activities, with concomitant increases in proteolysis in milk. Addition of plasmin inhibitors confirmed the heterogeneity of proteinase activities in milk, as urea-PAGE analysis of milk samples showed casein hydrolysis in milk after 7 d storage even in samples with inhibitors added; extent and heterogeneity of proteolysis was correlated with milk SCC. Rennet coagulation properties were not significantly correlated with SCC, or activities of measured enzymes. Milk of increasing SCC also exhibited decreased physical stability during incubation of milk at 37 °C. Pasteurized milk was more stable than raw milk, suggesting that the enzyme(s) or mechanisms leading to such instability are impaired by pasteurization. Overall, milk has a very heterogeneous proteolytic enzyme population, with a higher significance of non-plasmin enzymes, such as cathepsin D and cysteine proteinases, than perhaps previously recognised.

scholarly journals Bulk tank somatic cell count and associated microbial quality of milk from selected dairy cattle herds in Oyo State, Nigeria

2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Olufemi Olatoye ◽  
Adesola Amosun ◽  
Uzo Ogbu ◽  
Yemi Okunlade
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Health Management ◽  
Development Program ◽  
Raw Milk ◽  
Human Consumption ◽  
Quality And Safety ◽  
Milk Samples ◽  
California Mastitis Test

Improvement of traditional and nomadic milk production through dairy development program in Nigeria requires routine quality and safety monitoring of milk both at herd level and milk collection centers. A total of 411 bulk raw milk samples aseptically obtained from Ibarapa, Oyo and Oke-Ogun industrial milk collection centers were subjected to California Mastitis Test (CMT), Bulk Somatic Cell Count (BSCC) and bacteriological analysis for assessment of quality and safety of milk from the herds. One hundred and seven (26.0%) of the samples were CMT positive, while 74.0% were negative to CMT. The overall mean BSCC, TAC and TCC were 1.27×103 ± cells/mL, 1.12×103± 34 cfu/mL, 97.8±9.8 cfu/mL in the CMT negative milk samples while for the strong positive samples the mean BSCC, TAC and TCC were 4.33×106 ± cells/mL, 2.35×106 ± 453 cfu/mL, 189.3±41.1 cfu/mL respectively; these were higher than the Pasteurized Milk Ordinance acceptable limits. Positive correlation was found between CMT scores and bacterial contamination and between CMT scores and SCC was recorded. About 26.0% of the samples with positive CMT could be considered unsafe due to strong correlation with microbial contamination that could result in milk borne zoonoses and public health hazards. However, a greater proportion (76.9%) of the milk with negative CMT scores could be safe for human consumption after post-harvest pasteurization. Consequently, there is need to improve handling, environmental and milking hygiene; as well as proper herd and udder health management to improve quality and safety of Nigeria dairy products.

scholarly journals The presence of pathogens in milk of ewes in relation to the somatic cell count and subpopulations of leukocytes

2021 ◽  
Author(s):  
Tvarožková ◽  
Vašíček ◽  
Uhrinčať ◽  
Mačuhová ◽  
Hleba ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Dairy Farm ◽  
Subclinical Mastitis ◽  
Clinical Mastitis ◽  
Polymorphonuclear Cells ◽  
Coagulase Negative Staphylococci ◽  
Major Health Problem ◽  
Milk Samples

Mastitis is a major health problem of the udder in dairy sheep breeds. For diagnosis of subclinical mastitis, somatic cell count (SCC) is commonly used. The presence of pathogens in the udder causes the increase of leukocytes and thus SCC in milk. Therefore, the aim of this study was to evaluate the presence of pathogens in the milk of ewes and the possible relationship with SCC. The changes of leukocytes subpopulation in milk samples with high SCC were evaluated as well. The experiment was carried out on a dairy farm with the Lacaune breed. This study was conducted on 45 ewes (98 milk samples) without signs of clinical mastitis. Based on somatic cell count, samples were divided to five SCC groups: SCC1 &lt; 200 000 cells/ml (45 milk samples); 200 000 ≤ SCC2 &lt; 400 000 cells/ml (10 milk samples); 400 000 ≤ SCC3 &lt; 600 000 cells/ml (six milk samples); 600 000 ≤ SCC4 &lt; 1 000 000 cells/ml (six milk samples); SCC5 ≥ 1 000 000 cells/ml (31 milk samples). No pathogens were observed in the majority of milk samples (60.20%). Coagulase-negative staphylococci (CNS) were the most commonly isolated pathogens from the milk of ewes (86.11%). Staphylococcus epidermidis had the highest incidence from CNS (35.48%). In the SCC5 group, up to 79.31% of bacteriological samples were positive. The percentage of leukocytes significantly increased (P &lt; 0.001) in the samples with higher SCC (≥ 200 × 10<sup>3</sup> cells/ml) in comparison to the group SCC1. Also, the percentage of polymorphonuclear cells (PMNs) was significantly higher with increasing SCC (P &lt; 0.001). In conclusion, the presented results showed that the high SCC was caused by the presence of the pathogen in milk. Thus SCC &lt; 200 000 cells/ml and leukocyte subpopulation, especially PMNs, could be considered as important tools in udder health programs applied in dairy ewes.

Preservation and Storage Mechanisms for Raw Milk Samples for Use in Milk-Recording Schemes

1996 ◽  
Vol 59 (2) ◽  
pp. 151-154 ◽  
Author(s):  
HUMBERTO G. MONARDES ◽  
ROBERT K. MOORE ◽  
BRIAN CORRIGAN ◽  
YVON RIOUX
Keyword(s):  
Cell Count ◽  
Somatic Cell Count ◽  
Potassium Dichromate ◽  
Dairy Herd ◽  
Raw Milk ◽  
Storage Conditions ◽  
Sample Storage ◽  
Milk Samples ◽  
Whole Process ◽  
And Storage

This study, carried out by the Quebec Dairy Herd Analysis Service, compares (during summer conditions in Quebec) the performance of three types of preservatives for raw milk under four different systems of sample storage: no refrigeration, refrigeration at the laboratory only, refrigeration during transport and at the lab, and complete refrigeration from sampling at the farm to analysis. The objective was to determine the best preservative and storage conditions for protecting milk components during transportation and storage of raw milk samples collected at the farm and sent to a central testing lab for analysis. Milk samples were analyzed at day 3 and at day 7 after sampling to observe the effect of aging. A total of 12,480 samples were collected during the trial. The components studied were percentage of fat and protein and somatic cell count (SCC). In general, samples preserved with bronopol (2-bromo-2-nitropropane-1,3-diol and 2-bromo-2-nitropropanol) in liquid or in microtab tended to give higher readings for fat and protein contents than samples preserved with potassium dichromate. Significantly lower fat values were observed in 7-day-old samples compared to 3-day-old samples. Fat depression was more accentuated in nonrefrigerated samples. Under current methods of handling raw milk samples, refrigeration during the whole process of sampling, transportation, and until analysis, seems an ideal to attain to avoid significant reductions of fat values.

scholarly journals Evolution and factors influencing somatic cell count in raw milk from farms in Viçosa, state of Minas Gerais

2017 ◽  
Vol 39 (4) ◽  
pp. 393
Author(s):  
Leonardo Cotta Quintão ◽  
Adriano França da Cunha ◽  
Lindomar José Bragança ◽  
Kamila Soares Coelho ◽  
Mariana Fonseca Nunes ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Significant Variation ◽  
Somatic Cell Count ◽  
Raw Milk ◽  
Minas Gerais ◽  
Milk Samples ◽  
Factors Influencing ◽  
The Mean ◽  
Structured Questionnaire

The somatic cell count (SCC) of refrigerated raw milk reflects the occurrence of mastitis in the herd and the management of rural property. Therefore, this study aimed to evaluate the SCC of the refrigerated raw milk and its determinant factors in dairy properties of Viçosa, State of Minas Gerais. Monthly, milk samples were taken from 44 cooling tanks during 2012. A structured questionnaire was applied to evaluate the production and management characteristics of the herds. There was a significant variation (p < 0.05) in the mean SCC of the milk, which was lower from June to August. Higher mean SCC and percentages of samples above the limit set by the legislation were observed in months of higher rainfall and ambient temperature (p < 0.05). Mechanical milking, lower milk yield, productivity, inadequate milking procedures, equipment hygiene, and water quality were all factors that influenced (p < 0.05) the SCC of raw refrigerated milk. Milker training is required for production of low SCC milk. 

scholarly journals Diagnosing mastitis in early lactation: use of Somaticell®, California mastitis test and somatic cell count

2018 ◽  
Vol 17 (3) ◽  
pp. 723-729 ◽  
Author(s):  
José A. Ferronatto ◽  
Thaís C. Ferronatto ◽  
Marla Schneider ◽  
Lindomar F. Pessoa ◽  
Maiara G. Blagitz ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Early Lactation ◽  
California Mastitis Test

Relationship of Somatic Cell Count and Total Sulfhydryls in Milk

1986 ◽  
Vol 49 (2) ◽  
pp. 110-111 ◽  
Author(s):  
DANIEL R. SAMPLES ◽  
SUSAN L. DILL ◽  
RONALD L. RICHTER ◽  
CHARLES W. DILL
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Milk Protein ◽  
Cell Concentration ◽  
Chemical Parameters ◽  
Milk Samples ◽  
The Mean ◽  
Relationship Of ◽  
The Relationship

Individual milk samples from 32 cows were analyzed to determine the relationship between somatic cell concentration and total sulfhydryl concentration (cysteine plus reduced cystine). A significant relationship was detected between somatic cell count, which ranged from 1.7 × 104 to 1.0 × 107 cells/ml, and total sulfhydryls per gram of milk protein. The regression equation, total sulfhydryls/g of milk protein = 31.96 + 7.99 (log10 somatic cell count) with r2 = 0.19, was calculated. The mean total sulfhydryl concentration was 73.1 μmol/g of protein. The minimal effect of somatic cell concentration on total sulfhydryl concentration indicates that somatic cell concentration should have little influence on chemical parameters of milk protein determined by sulfhydryl analysis when proper experimental controls are used.

scholarly journals Haptoglobin and serum amyloid A in relation to the somatic cell count in quarter, cow composite and bulk tank milk samples

2007 ◽  
Vol 74 (2) ◽  
pp. 198-203 ◽  
Author(s):  
Maria Åkerstedt ◽  
Karin Persson Waller ◽  
Åse Sternesjö
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Somatic Cell Count ◽  
Serum Amyloid A ◽  
Dairy Farms ◽  
Serum Amyloid ◽  
Bulk Tank Milk ◽  
Amyloid A ◽  
Milk Samples ◽  
Bulk Tank

Milk somatic cell count (SCC) is the gold standard in diagnosis of subclinical mastitis, and is also an important parameter in quality programmes of dairy cooperatives. As routine SCC analysis is usually restricted to central laboratories, much effort has been invested in the search for alternative biomarkers of mastitis and milk quality, including the presence in the milk of the acute phase proteins (APP), haptoglobin (Hp) and serum amyloid A (SAA). The aim of this study was to investigate relationships between Hp, SAA and SCC in quarter, cow composite, and bulk tank milk samples. Cows (n=165), without any clinical signs of disease or abnormalities in the milk or udder, from three different dairy farms, were used. Cow composite milk samples from all cows delivering milk at the sampling occasion were taken once in each herd. In one of the farms, representative quarter milk samples (n=103) from 26 cows were also collected. In addition, bulk tank milk samples from 96 dairy farms were included in the study. Samples were analysed for Hp, SAA and SCC, and relationships between the parameters were evaluated at quarter, cow and tank milk levels using Chi-square analysis. Milk samples were categorized according to their SCC, and the presence, or no presence, of SAA and Hp, based on the detection limits of the screening methods (0·3 mg/l and 1·0 mg/l for SAA and Hp, respectively). Hp and SAA were found in milk at quarter, cow composite and bulk tank levels. A large proportion (53%) of the animals had detectable milk concentrations of APP, and SAA was detected more frequently, and at higher concentrations than Hp, regardless of sample type. SAA was detected in as many as 82% of the bulk tank milk samples. Significant relationships were found between Hp, SAA and SCC at quarter and cow composite milk levels, but only between SAA and SCC at bulk tank milk level. Detectable levels of APP were more common at high SCC.

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