Proteolysis in Samples of Quarter Milk with Varying Somatic Cell Counts. 1. Comparison of Some Indicators of Endogenous Proteolysis in Milk

Roux, Yves Le; Colin, O.; Laurent, François

doi:10.3168/jds.s0022-0302(95)76749-2

Cited by 80 publications

(94 citation statements)

References 21 publications

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“…Haenlein et al (1973) present significantly lower contents of casein, a s1 -CN, b-CN, b-lactoglobulin, a-lactalbumin and whey proteins, and a lower casein number with increasing degrees of subclinical mastitis and SCC. A study by Le Roux et al (1995) showed that protein composition starts to change even at low levels of SCC (.250 000 cells/ml) in udder quarter milk. In this study, protein composition was also influenced in milk from affected udder quarters in Group 2, for which the udder quarter mean SCC was 285 000 cells/ml.…”

Section: Forsbä Ck Lindmark-må Nsson André N and Svennersten-sjaunjamentioning

confidence: 99%

Evaluation of quality changes in udder quarter milk from cows with low-to-moderate somatic cell counts

Forsbäck

Lindmark-Månsson²,

Andrén

et al. 2010

Animal

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Much emphasis has been put on evaluating alterations in milk composition caused by clinical and subclinical mastitis. However, little is known about changes in milk composition during subclinical mastitis in individual udder quarters with a low-tomoderate increase in milk somatic cell count (SCC). This information is needed to decide whether milk from individual udder quarters with a moderate-to-high increase in milk SCC should be separated or not. The aim of this study was to determine how milk composition in separate udder quarters is affected when cow composite milk has low or moderately increased SCC levels. Udder quarter and cow composite milk samples were collected from 17 cows on one occasion. Milk yield was registered and samples were analyzed for SCC, fat, total protein, whey proteins, lactose, citric acid, non-protein nitrogen (NPN), lactoferrin, protein profile, free fatty acids (FFAs), lactate dehydrogenase (LDH), proteolysis, sodium and potassium. Bacteriological samples were collected twice from all four quarters of all cows. The cows were divided into three groups depending on their SCC at udder quarter level. The first group comprised healthy cows with four udder quarters with low SCC, , 50 000 cells/ml; composition was equal when opposite rear and front quarters were compared. In the second and the third groups, cows had one udder quarter with 101 000 cells/ml , SCC , 600 000 cells/ml and SCC . 700 000 cells/ml, respectively. The remaining udder quarters of these cows had low SCC (, 100 000 cells/ml). Despite the relatively low average cow composite SCC 5 100 000 cells/ml of Group 2, milk from affected udder quarters exhibited lower casein number, content of lactose and b-casein (b-CN), while the content of whey protein, sodium, LDH and a-lactoalbumin (a-la) were higher compared to healthy opposite quarters. In addition to these changes, milk from affected udder quarters in Group 3 also exhibited lower values of potassium and a s1 -casein (a s1 -CN) and higher values of lactoferrin when compared to milk from opposite healthy quarters. This indicates that even when the SCC in cow composite milk is low, there might exist individual quarters for which milk composition is changed and milk quality impaired.

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Section: Forsbä Ck Lindmark-må Nsson André N and Svennersten-sjaunjamentioning

confidence: 99%

Evaluation of quality changes in udder quarter milk from cows with low-to-moderate somatic cell counts

Forsbäck

Lindmark-Månsson²,

Andrén

et al. 2010

Animal

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“…These modifications are in relation to the level of SCC and are linked to the germ present in the udder, particularly in cases of clinical mastitis [19,47,48]. The threshold of SCC for a normal milk is variable in function of the authors but more often than not over 10 5 cells/mL [19,41,69]. The decrease of synthesis in mammary epithelial cells (indicated by a decrease in lactose content) and the proteolysis (indicated by an increase in proteose-peptone content and plasmin activity) are statistically significant for low SCC (Tab.…”

Section: The Relationship Between Scc and Milk Composition In Quartermentioning

confidence: 99%

“…In UHT milk, plasmin seems implicated in gelation during storage [35]. Milk obtained from mastitic or high SCC quarter milk contains high concentrations of plasmin [41]. Within the plasmin system, activators and inhibitors control plasmin activity.…”

Section: An Increase In Proteolytic Activitiesmentioning

confidence: 99%

“…Although the effect of an increase in cell concentration on the health of the animal is known from a pathological point of view, the consequences on the biochemical composition and technological properties of milk and dairy products remain unclear. Little research has described the relationship between somatic cells and the biochemical quality of milk [19,40,41] and dairy products [1-3, 7, 15, 34, 43] for quarter or tank milk.…”

Section: Introductionmentioning

confidence: 99%

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Polymorphonuclear proteolytic activity and milk composition change

Roux¹,

Laurent²,

Moussaoui³

2003

Vet. Res.

117

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-Relationships between Quarter Milk Cell Count (QMCC) and Tank Milk Cell Count (TMCC) with milk biochemical and technological parameters in milk and dairy products were investigated. All parameters measured were affected by the increase of TMCC and QMCC between 0 and 600 000 cells/mL. The variable effect of lactation stage which is different for different authors, is discussed. The three mechanisms, measured during the inflammation of the udder, implicated in the modification of milk quality are described (a decrease in synthesis, a decrease in the milk barrier permeability and an increase in proteolytic activities). The direct effect of plasmin in caseinolysis is well known; the specific role of the increase of somatic cells (especially PMN) in the modification of milk quality is described. Several specific proteolytic activities of PMN are described and the impact of these activities on caseinolysis is evaluated. Two hypothetical mechanisms of caseinolysis by PMN are suggested and a synthetic scheme of the role of plasmin, bacteria and somatic cells in caseinolysis is discussed. caseinolysis / mastitis / milk / PMN proteases / SCC

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“…On a more fundamental basis, mastitis involves three phenomena: a decrease of synthesis [22,24], an increase in permeability of the blood-milk barrier [24,28] and an increase in proteolytic activity in milk [16,24]. In the case of a lipopolysaccharide (LPS) infusion, plasmin and somatic cell proteases are the main origins of endogenous proteolysis [26].…”

Section: F Moussaoui Et Almentioning

confidence: 99%

Proliferation and immunoglobulin production of hybridoma cells cultured on mastitic whey

Moussaoui¹,

Roux²,

Laurent³

2003

Lait

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-Lipopolysaccharide experimental mastitis was performed in order to obtain the same milk composition change involved in a clinical mastitis without, however, any bacterial proteolytic participation. Whey from milk with a high somatic cell count (SCC) had a lower mitogenic effect on anti-human prolactin-hybridoma (anti-hPL) cell culture but a greater immunostimulating effect than that of the fetal calf serum regularly used in cell culture. This immunostimulating effect was more pronounced when expressed per cell, with an effect two-to three-fold higher than that of fetal calf serum (P < 0.01), which illustrated the efficiency of such a complement. Cell culture / whey / proteolysis / mastitisRésumé -Prolifération et production d'immunoglobulines d'hybridomes cultivés sur lactosérum de mammite. Une mammite expérimentale à lipopolysaccharide a été menée en vue d'obtenir le même changement de composition du lait que celui observé dans les cas de mammite clinique, en éliminant toutefois toute interaction avec la protéolyse bactérienne. Le lactosérum issu d'un lait à fort dénombrement cellulaire (DC) avait un effet mitogénique plus faible sur une culture cellulaire d'hybridomes anti-prolactine humaine (anti-hPL) mais toutefois un effet immunostimulant plus important que le sérum foetal de veau. Cet effet immunostimulant a été plus marqué lorsqu'il était exprimé par cellule, avec un effet 2 à 3 fois supérieur à celui observé avec le sérum de veau foetal (P < 0,01), traduisant l'efficacité de la complémentation par un lactosérum issu d'un lait à fort DC.Culture cellulaire / lactosérum / protéolyse / mammite

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Proteolysis in Samples of Quarter Milk with Varying Somatic Cell Counts. 1. Comparison of Some Indicators of Endogenous Proteolysis in Milk

Cited by 80 publications

References 21 publications

Evaluation of quality changes in udder quarter milk from cows with low-to-moderate somatic cell counts

Evaluation of quality changes in udder quarter milk from cows with low-to-moderate somatic cell counts

Polymorphonuclear proteolytic activity and milk composition change

Proliferation and immunoglobulin production of hybridoma cells cultured on mastitic whey

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