Mastitis is an inflammation of the mammary gland that can decrease milk production and quality. It is usually caused by bacterial infections such as Streptococcus agalactiae. Mastitis increases somatic cell counts in milk and decreases important milk components like lactose, casein and fat. It also changes the protein composition of milk. These changes negatively impact milk quality and the production of dairy products. To control mastitis and improve milk quality, farmers should focus on udder health through proper milking procedures, equipment maintenance, environmental management and treatment of clinical cases.

1. Mastitis and its effect on
milk processing
Atheer Jasim Mohammed

2. 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

3. What’s mastitis ?
Inflammation of one or more
quarters of the udder
Normal Inflamed
Swelling
pain
warm
redness

4. 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

5. What causes mastitis ?
Bacteria ( ~ 70%)
Yeasts and molds ( ~
2%)
Unknown ( ~ 28%)
physical
trauma
weather extremes

6. Where do these organisms
come from ?
Infected udder
Environment
bedding
soil
water
manure
Replacement
animals

7. 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

8. 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

9. 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

10. Other organisms
Pseudomonas aeruginosa
outbreaks of clinical mastitis
Serratia
outbreaks of clinical mastitis
Corynebacterium pyogenes
Fungi
Candida
Mycoplasma bovis

11. Process of infection
Organisms 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

12.  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

13. 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

14. 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

15. Effects on physical properties
Isoelectric point (pH) increased with rising of somatic
cells.
no correlation between mastitis disease and freezing point

16. 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

17.  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

18.  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

19. Reference in Hard copy
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