On-line sensing of suitabilityof milk for cheese making

LeitnerDr. Gabriel National Mastitis Reference Center,Kimron Veterinary Institute, Israel

Dr. Uzi Merin, Dr. Nissim SilanikoveDepartment of Food Science,

Department of Animal Physiology,Agricultural Research Organization,

The Volcani Center, Israel

Milk quality:fat, total proteins, casein,

curd and…..intramammary Infection

Cheese quality:yield, structure, smell, flavor,

shelf life …..

Traditional farming

1. Along the lactation different products are produced

2. Milk from clinically infected glands is discarded

Modern dairy forming

1. Animals are milked while at different stages of lactation

2. A large number of glands are infected with a variety of bacteria

0 1 2 3 4 5 6 7 8 9

10

100

1000

10000

log

Som

atic

Cel

l Cou

nt

Curd firmness (A30 Optigraph)

Dry curd vs. SCC of 15 cow’s bluk milkCorralation (r= 0.24)

62 64 66 68 70 72 74 76 78 800

200

400

1400

1600

1800SC

C x

100

0

Dry curd (g/L)

Casein vs. dry curd of 15 farms bluk milkCorralation (r= 0.81)

2.35

2.40

2.45

2.50

2.55

2.60

2.65

2.70

2.75

2.80

62 64 66 68 70 72 74 76 78 80

Dry curd (g/L)

Cas

ein

(%)

Animal model built on the gland level

One udder-half identified with CNSspecies and the contra-lateral beingfree of bacteria

+ -

S. capraeS. chromogenesS. epidermidisS. simulansS. xylosus

+ -

Curd yield and clotting time of goat milk from infected vs. uninfected udder-halves

Uninfected

0

100

200

300b P < 0.02

Clo

tting

tim

e (s

)

200

210

220

230

240a

P < 0.0001

Cur

d yi

eld

(g/L

; wet

bas

is)

Infected

Strep. dysgalactiae

Staph. chromogenes

Healthy Infected

0.5

3.5

Milk

K/d

ay

Day in milk

SC

C (1

000)1000

100

Milk yield and SCC along the glands uninfectedlactation of

0.5

3.5

Milk

(K/d

ay)

Days in milk

SC

C (x

100

0)1000

100

Milk yield and SCC along the glands infectedlactation of

* Many of the animals with subclinical chronic infection arenot noted because there are no recognizable symptoms and the milk appearance is normal

* End of lactation goats show increased SCC regardless of IMI

** Routine milk testing such as CMT on the animal side or more advanced techniques like the sophisticated cell counters allowthe identification of subclinically infected animals close to theoccurrence of the infection. However, it is laborious and/or require special equipment to perform

*** On-line computerized milking systems are designed in partto overcome these conditions and to apply genuine real-timedata acquisition on individual animals, including milk yield and conductivity

0.5

3.5

Milk

(K/d

ay)

Days in milk

SC

C (x

100

0)1000

100

Milk yield and SCC along the lactation

P[F]R2ELML-IML-F395641# (Quarters)

P<0.0010.452204±4.9119±8.599±9.2DIM

P<0.0010.3330.99±0.181.57±0.182.28±0.16Milk (L d -1)

P<0.0010.299403±947211±1197129±48SCC (x 103)

P<0.050.06276.1±0.3468.7±0.3272.7±0.32Fat (g L -1)

NS0.05951.8±0.1850.1±0.1747.7±0.17Protein (g L -1)

NS0.05136.3±0.1634.1±0.1135.8±0.11Casein (g L -1)

P<0.0010.29474.6±0.5167.9±1.4476.4±1.43% Casein

P<0.0010.20543.8±0.1340.5±0.1147.9±0.12Lactose (g L -1)

Mean and SE of sheep milk and constituentsaccording to time in the lactation and IMI

Mean and SE of sheep milk and constituentsaccording to time in the lactation and IMI

Clo

tting

tim

e (s

ec)

Cur

d fir

mne

ss (V

)

ML-F = mid lactation free; ML-I = mid lactation infected; EL = end lactation

0 10 20 30 40 50 60

100

1000

10000

Goats

Log

SC

C

22 %

46 %

32 %

Log SCC of goat at mid-lactation with and without IMI and at the end of lactation without IMI

Low quality curd

100

1000

10000

0 5 10 15 20 25 30 35 40

Curd firmness (Cf)

correlation ( r= -0.4)

Log SCC and Cf of curd of goat milk at mid lactation with and without IMI and at the end

of lactation without IMI

Log

SC

C

Low quality curd

1

2

3

4

5

6

0 5 10 15 20 25 30 35 40

% L

acto

se

Lactose lower than 4%

% lactose and Cf of curd of goat milk at mid lactation with and without IMI and at the end

of lactation without IMI

Curd firmness (Cf)

0

1

2

3

4

5

6

0 5 10 15 20 25 30 35

Curd firmness (V)

Per

cent

lact

ose

in m

ilk

Sheep Goat Cow

Influence of percent lactose in milk on curdfirmness as measured by the Optigraph

* It was found that to date, lactose content is the best indicator for milk quality for cheese making.

* It is already implemented in Afilab in dairy cows milking parlorsIt will enable on-line sensing of cow producing milk unfit for cheese making

* Feasibility test of the system for small ruminantswas conductedThe system will enable direct and cheap dailyidentification of animals with milk unsuitable for cheese making

On-line computerized milking systems enables genuine real-time data acquisition on individual animals with milk unsuitable for cheese making

Thanks