Mastitis and its effect on milk processing

Atheer Jasim Mohammed

Topics

Disease definition Disease causes Somatic cells Effects on milk production Effects on milk composition like (TS, SNF, Lipid, total protein, enzyme, salts ) Effects on physical properties Effects on milk quality Effects on milk products

What’s mastitis ?

� Inflammation of one or more quarters of the udder

Normal Inflamed

Swellingpainwarmredness

How severe can mastitis be ?

� Subclinical Mastitis

� ~ 90 -95% of all mastitis

cases

� Udder appears normal

� Milk appears normal

� Elevated SCC (score 3-5)

� Lowered milk output (~

10%)

� Longer duration

� Clinical Mastitis � ~ 5 - 10% of all mastitis

cases� Inflamed udder� Clumps and clots in milk� Acute type

� major type of clinical mastitis

� bad milk� loss of appetite� depression� prompt attention needed

� Chronic type� bad milk� cow appears healthy

What causes mastitis ?

� Bacteria ( ~ 70%)� Yeasts and molds ( ~

2%)� Unknown ( ~ 28%)

� physical� trauma� weather extremes

Where do these organisms come from ?

� Infected udder� Environment

� bedding� soil� water� manure

� Replacement animals

BACTERIA

Streptococci� Environmental

� S. uberis� S. dysgalactiae� S. equinus

� More subclinical mastitis

� Environment� Predominant early

and late lactation

� Contagious� S. agalactiae

� Clinical mastitis� Cannot live

outside the udder

� Treated easily with penicillin

BACTERIA

Staphylococci� Staph. aureus

� Summer mastitis� Spread by milking equipment and milker’s

hands� Persistent, difficult to eliminate� If unattended leads to chronic mastitis

� Other Staph� Found normally on skin� Lowers milk yield� Elevated SCC� Easily responds to antibiotics� Relapse frequently seen

BACTERIA Coliforms

� Groups of organisms� E. coli, Klebsiella, Enterobacter

� Environmental source (manure, bedding, barns, floors and cows)

� Coliforms cause acute clinical mastitis� high temp, and inflamed quarter � watery milk with clots and pus� toxemia

vaccine

Other organisms

� Pseudomonas aeruginosa� outbreaks of clinical mastitis

� Serratia� outbreaks of clinical mastitis

� Corynebacterium pyogenes� Fungi� Candida� Mycoplasma bovis

Process of infectionOrganisms invade the udder through

teat canal

Migrate up the teat canal and colonize the

secretory cells

Colonized organisms produce toxic substances

harmful to the milk producing cells

Milk Production: Decreases milk production by causing tissue damage, reduced lactose production and scar tissue formation in the udder.

Milk Quality and Composition: Increasing somatic cell count

•Polymorphonuclear neutrophils Decreasing lactose, casein, and fat production, Increasing blood components such as Na, K, Cl,

bicarbonate, IgG and serum albumin. •Electrical potential disrupted

Bacteria, blood cells and enzymes• Proteolysis• Lipolysis and globule breakdown•Off flavors

Mastitis Affects on Milk Composition

changes of components in an infected milk.

Components % fresh milk An infected milk

Fat 3.45 3.20

Protein 3.61 3.56

Lactose 4.85 4.40

Somatic cell (cell/ml)

50-200 ×103 200-5000 ×103

protein changing in an infected and fresh milk

Components/ unit Fresh milk An infected milk

Protein % 3.61 3.56

Casein (mg/ml) 27.9 22.5

Whole whey protein (mg/ml) 8.2-8.7 13.1-19.8

αs-Casein (mg/ml) 9.35-13.3 3-8.5

β-Casein (mg/ml) 5.5-11.5 0.8-7.5

κ- Casein (mg/ml) 1.6 1.9

Para-κ-Casein (mg/ml) 0 0.5

β- lactoglobulin (mg/ml) 4-4.25 2.7-4.3

α- lactalbumin (mg/ml) 1-3.2 0.6-2.5

Bovine serum albumin (mg/ml) 0.1-0.3 0.7-21.5

Immune globulins (mg/ml) 0.3-1.3 2.5-18.3

Proteose peptone (mg/ml) 1.8 9.3

Lactoferrin (mg/ml) 0.1-0.2 6.2

Membrane fat globule (mg/200 gm. fat) 513.7 408.8

Effects on physical properties

Isoelectric point (pH) increased with rising of somatic cells.

no correlation between mastitis disease and freezing point

Effects on milk products

Mastitis disease effects on cheese making via influence on time of milk clotting by rennet, softness of clotting, more leak of whey and developed of acidity.

lower cohesion of clot and decreased of starter culture activity in milk produced from infected cows.

In study shows that infected milk takes long time to coagulate from 23 to 11.8 minutes compared with fresh milk is 4.1 minutes.

milk from infected animals produces low coagulate with high whey and short storage stability with high proteolysis in yoghurt.

infected milk effects on characteristics of butter which produced by developed acidity and reduced of fat due to lipase activity.

mastitis disease is causing of increased a SCC decreased of chemical composition in milk and its qualities. dropped of thermal stability to dairy products

Increasing of SCC in milk which used in UHT milk led to increased proteolysis and fatty during storage and decreased of storage stability and sensory evaluation.

Increasing of SCC in milk which used in cream processing led to increase of proteolysis, shortage storage and bad sensory evaluation.

Effects on milk products

establishment of goals for udder health

maintenance of clean, comfortable environment proper milking procedures proper maintenance and use of milking equipment good record keeping appropriate management of clinical mastitis during

lactation effective dry cow management maintenance of biosecurity for contagious pathogens

and culling of chronically infected cows regular monitoring of udder health status periodic review of mastitis control program

10 ways to rise milk quality and stopped mastitis

Reference in Hard copy

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