MILKING PROCESS MANAGEMENT AND THE QUANTITY AND QUALITY OF MILK PRODUCED IN TWO MILKING SYSTEMS

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1

MILKING PROCESS MANAGEMENT AND THE QUANTITY AND QUALITY OF MILK PRODUCED IN
TWO MILKING SYSTEMS

Jan Miciński, Grzegorz Zwierzchowski, Karolina Ropelewska

University of Warmia and Mazury in Olsztyn
,

Olsztyn
,
Poland


(Поступила в редакцию 04.06.2010 г.)


Abstract.
The study was conducted in 2009, in two farms (F
1
and F
2
) located in the Province of Warmia and Mazury, NE Poland. The cattle herds
in farms F
1

and F
2

consisted of 188 and 242 dairy cows, respectively. Data recorded in computer
-
assisted dairy herd management systems (“Alpro”
in F
1
and “Dairy Plan” in F
2
) were used in the experiment. The objective of the study was to evaluate the milking process and to d
etermine the qua
n-
tity and quality of milk collected in two milking parlors in farms F
1

and F
2

in 2009. The quantity of collected and sold milk was higher in farm F
2
,
compared with F
1,
due to a higher total milk yield and a higher number of dairy cows in fa
rm F
2
. Milk produced in farm F
2

had a higher protein co
n-
tent and a lower fat content than milk produced in farm F
1
. An analysis of the effect of cow’s age on milk composition showed that milk from primip
a-
rous cows contained less fat and protein than milk f
rom multiparous cows. Milk from primiparous cows in farm F
2

had a higher fat content and a
lower protein content, in comparison with milk from primiparous cows in farm F
1
. Milk from multiparous cows in farm F
1

had a higher content of
protein and fat than m
ilk from multiparous cows in farm F
2
. The somatic cell count (SCC) in milk was similar in both farms throughout the year,
while bacterial cell counts were found to increase in the summer. Mastitis incidence rates were higher in farm F
1

than in farm F
2
, due

to worse ma
n-
agement and sanitary conditions. The tandem milking parlor was characterized by higher performance capacity than the herringb
one milking parlor.


Introduction.
The quality of raw milk purchased by the Polish dairy industry has been improving
steadily in the
past years in an ongoing effort to comply with European Union standards (
Danków

et al. 2004). To ensure conformity
with the EU requirements, Poland abandoned the purchase of class III milk (2000), class II milk (2003) and class I milk
(2006
). As of January 2007, only prime class milk is purchased by industrial producers (
Danków et al. 2004, Woyke

2008).

The hygienic quality of milk is determined by microbiological and cytological parameters as well as the presence of
antibiotics and other i
nhibitory substances (
Litwińczuk

2001). The microbiological quality of milk is indicated by total
bacterial counts (TBC), and its cytological quality is expressed by somatic cell counts (SCC) (
Miciński

2001). Somatic
cells comprise necrotized cells of the
glandular tissue as well as leukocytes which are transferred to milk during milking
(
R
ogowska

2007). According to Polish Standard PN
-
A
-
86002 (1995), the allowable limits for prime class milk are set
at 100,000 bacteria (microorganisms) and 400,000 somatic
cells per milliliter (
W
oyke

2006).

Somatic cell counts in milk change with the cow's age, season and lactation stage (
M
iciński

2001b). Increased SCC
levels could suggest udder irritation caused by milking errors, defective milking equipment, inadequate
nutritional and
housing standards and metabolic diseases (
D
anków
). Elevated SCC levels are usually indicative of mastitis (
R
ogowska

2007). Inflammations of the mammary glands are the most serious health hazard in dairy cattle. Mastitis causes vast
financia
l losses due to the production of milk unfit for consumption, a low milk yield and high treatment costs (
Min
a-
kowski

et al. 2008). Mastitis is accompanied by increased concentrations of highly pathogenic bacteria in milk. Co
n-
ta
m
inated milk is characterized
by elevated catalase levels and increased pH which, in acute inflammations, may exceed
7 (
K
roll

et al. 1996). Mastitis incidence and milk SCC levels are conditioned environmentally in 90
-
95%, while the
bovine genotype is responsible for the above condition

in only 5
-
10% (
S
ender

et al. 2000).

In line with modern cattle rearing standards, tie
-
stall systems are being gradually replaced with free
-
stall systems. In
addition to changes in building construction and technical infrastructure, this transition also r
equires new milking met
h-
ods (
S
zulc

2006). Research results have demonstrated that the milk obtained from milking parlors is characterized by
higher quality than the milk acquired from bucket milking machines or pipeline milking equipment applied in the co
w-
shed.

The most advanced milking solution comprises an automatic milking system (
L
ipiński

2008). Full automation of the
milking process attracts the growing interest of Polish milk producers (
G
aworski

2008). The introduction of milking
robots revolutionizes

the entire milk acquisition "philosophy" (
K
upczyk

et al. 2003). In robotic systems, the entire mil
k-
ing process is performed by a machine (
Czarnociński and Lipiński

2008). This advanced technology takes some getting
used to not only for man, but above all


for the animals. The main difference between an autimatic and a conventional
milking system is that daily milking frequency is a resultant of cow training and herd management effectiveness
(
Lipiński 2008). Research results indicate that milking robots cu
t milking time by 30
-
40%. The transition from a 2
times/day to a 3 times/day milking system increases milk yield by 3% to 25% (Gaworski 2008). An additional a
d-
vantage of that method is that each udder quarter is identified, evaluated and milked individuall
y (Lewandowski 2008)
which allows to avoid milking of empty teats and supports a precise evacuation of milk from every udder quarter
(Gaworski 2008). The teat localization system relies on a single or several high
-
precision measurement sensors co
n-
nected to

a double
-
laser optical camera (Kupczyk et al. 2003, Lewandowski 2008). A milking robot is able to detect
milk that does not meet premium class requirements. Rejected milk is directed to separate churns. An identical classif
i-
cation procedure is applied to
eliminate milk containing antibiotics and colostrum (Lewandowski 2008). The install
a-
tion of an automated milking system delivers a variety of benefits and brings the farm up to modern production stan
d-
ards (Kupczyk et al. 2003).

The objective of the study w
as to evaluate the milking process and to determine the quantity and quality of milk co
l-
lected in two milking parlors in farms F
1

and F
2

in 2009. The total volume of milk produced was calculated based on the
quantity [kg] of collected milk, milk fat and mi
lk protein, and the content [%] of fat and protein in milk. Milk quality
was determined based on total bacterial counts (TBC) and somatic cell count (SCC).


2

Materials and methods
.
The study was conducted in 2009, in two farms (F
1
and F
2
) located in the
Province of
Warmia and Mazury, NE Poland. Farm F
1

is a Research Station of the University of Warmia and Mazury in Olsztyn
(UWM) and farm F
2

is an Experimental and Production Station Ltd. The dairy cattle herd in farm F
1

consisted of 188
cows of the followi
ng breeds: Polish Holstein
-
Friesian (PHF), Jersey (JER), Polish Red (PR), and PHF x JER and PHF
x Simental hybrids. The cows were milked by two milkers, twice a day, in a double
-
six De Laval tandem milking pa
r-
lor. The dairy cattle herd in farm F
2

consisted

of 242 PHF cows. The cows were milked by two milkers, twice a day, in
a double
-
ten Westfalia Surge herringbone milking parlor.

Data recorded in computer
-
assisted dairy herd management systems (“Alpro” in F
1
and “Dairy Plan” in F
2
) were
used in the experi
ment. The systems monitored milking time per cow and the number of cows milked per hour. The
acquired data provided a basis for analyzing cattle management conditions in both farms, comparing the two types of
milking parlors, and calculating parlor perform
ance capacity per hour and stall use rate. The following formula was
used:
stall use rate = number of cows milked per hour/number of stalls.

Results and discussion
.
Herd characteristics and cattle housing systems are presented in Table 1. In both farms, th
e
studied animals were housed in a free
-
stall system. The barn in farm F
1

featured four rows of lying boxes, while farm F
2

comprised one barn with four rows of lying boxes, one barn with three rows of boxes and 50 additional tie
-
stalls used as
calving stal
ls. According to
S
awa

(2001), the introduction of a free
-
stall system has a positive effect on the animals'
health, milk yield and the hygienic quality of milk.

The cattle in farm F
1

were fed a partially mixed ration (PMR), and the concentrate was provide
d at four feeding st
a-
tions. In farm F
2
, the animals were fed a partially mixed ration in the first barn and a total mixed ration (TMR) in the
second barn. In both farms, barns were equipped with feeding tables and waterers. In F
1
, the feeding table was set

ou
t-
doors under a canopy situated along the longer wall of the building. In F
2
, feeding tables were set indoors. In the barn
with the TMR feeding regime, the tables were situated along the longer walls of the building, and in the barn applying
the PMR regi
me


along the feeding corridor. In both farms, feed was served on the table twice daily. The concentrate
containing mainly locally grown cereal crops was prepared on the premises.

Table 1



Cattle herd characteristics

Parameter

Farm

F
1

F
2

Housing
system

Free
-
stall system

four rows of boxes

Free
-
stall system

lying boxes

Number of cows
[head]

200

280

Breed

Polish Holstein
-
Friesian
(PHF), Jersey, Polish Red,
PHF x Jersey and PHF x
Simental hybrids

Polish Holstein
-
Friesian (PHF)

Production groups of

cows

1.

High
-
yielding cows (above
20 kg milk)

2.

Medium
-

and low
-
yielding
cows (below 20 kg milk)

1.

High
-
yielding cows (above 25 kg
milk)

2.

Medium
-
yielding cows (15
-
25 kg
milk)

3.

Low
-
yielding cows (below 15 kg
milk)

Feeding system

PMR (TMR up to 20 kg

milk + feeding stations)

PMR (TMR up to 25 kg milk +
feeding stations)

Watering equipment

Heated double
-
drink w
a-
terers

indoor

Insulated waterers

Indoor

Number of feeding
stations

6

5

Feeding table

Outdoor, under the roof

Indoor

Reproduction

Artificial insemination

Natural mating and artificial
insemination

Manure removal

Once daily, with a tractor

Twice daily, with a tractor

Ventilation system

Gravity ventilation

Gravity ventilation + two fans
used on hot days

Connector alley

Connects the
milking
parlor to the barn

-

indoor

Connects the milking parlor to the
barn

-

outdoor

Both farms were equipped with gravity ventilation systems. According to
S
zulc

(2006), effective ventilation e
n-
hances milk yield. In this experiment, manure was removed
from both farms with the use of a tractor


once a day in
farm F
1
, and twice daily in farm F
2
.

Table 2



Milking parlor characteristics

Parameter

Farm

F
1

F
2

Manufacturer

De Laval

Westfalia Surze

Milking parlor type

tandem

herringbone

Year of
installation

2003

1999

Number of milking stalls

2
x

6

2
x
10


3

Milking method

Individual

Group

Entrance/exit gate

Two
-
way

Two
-
way

Non
-
return gate

yes

no

Gate control

Manual and automatic

Manual and pneumatic

Milk meters

FloMaster Combi with a
cut
-
off
valve (12)

Matatron 12

(20)

Under pressure

44 kPa

42 kPa

Milking units

“Harmony”, capacity
-

360 ml, transparent
collection tanks

“Classic”, capacity
-

300 ml, transparent
collection tanks

Cleaning pipeline

Constructed of acid
-
resistant steel

Constructed of plastic
materials

Milking pipeline

Constructed of stainless
steel

Constructed of stainless
steel

Cleaning process

Electronic control,
alarm function

Washing station with
water heaters, alarm
function

Teat disinfection device

Yes

Yes

Electronic scales

Yes

Yes

Milking parlor characteristics are compared in Table 2. In

the tandem milking parlor, the animals entered and exited
the building individually, while in the herringbone facility, each side of the parlor was occupied in groups. In the he
r-
ringbone parlor, the herd had to be divided into production groups with simil
ar milking times to prevent slower milking
animals from blocking the access for faster milking cows. As noted by
S
ZULC

(2004), in tandem parlors with an ind
i-
vidual loading and unloading system, production groups do not have to be formed because both slow a
nd fast milking
animals leave the building directly after the end of milking.

Milking stalls in both parlor types were equipped with milk meters. In F
2
, the applied under pressure was 2 kPa
higher than in F
2

(42 kPa). The milking parlor in F
1

was equipped
with 360 ml Harmony milking units with transparent
collection tanks. Farm F
2

applied 300 ml Classic milking units, also with transparent collection tanks. The tandem pa
r-
lor featured acid
-
resistant steel cleaning pipelines, while plastic pipelines were used

in the herringbone facility. The
cleaning process was electronically controlled in both farms. Both facilities were equipped with stainless steel milking
pipelines as well as entrance/exit gates with electronic weighing scales in the rear section of the p
arlor. According to
L
itwińczuk

et al. (2002), milking hygiene and the cleanliness of milking devices significantly affect milk quality.

Table 3



Milk performance traits of cows

Specification

Statistical
measure

Farm

F
1

F
2

Number of cows milked per
hour per
milking stall [head]

LSM

Se

7.3
x

8.93

5.7

4.19

Number of cows milked per hour per
milking parlor [head]

LSM

Se

88

18.65

113
xx

21.34

Average annual yield of milk sold per
farm [kg]

LSM

Se

1019209

85.07

2955781
xx

72.76

Average milk yield per
primiparous cow
over 305
-
day lactation [kg]

LSM

Se

7289

23.56

8467
xx

21.08

Average milk yield per multiparous cow
over 305
-
day lactation [kg]

LSM

Se

8143

19.06

9123
xx

23.67

Average milk fat yield [kg]

LSM

Se

332

12.06

380
x

11.99

Average milk protein
yield [kg]

LSM

Se

270

10.44

295

12.31

Average fat content of milk [%]

LSM

Se

4.14
x

3.12

4.02

4.77

Average protein content of milk [%]

LSM

Se

3.29

2.67

3.46
x

6.32

Average SCC [ths/ml]

LSM

Se

278
x

4.80

242

5.03

Average TBC [ths/ml]

LSM

Se

12.90
x

3.33

8.83

3.21

xx


p ≤ 0.01; x
-

p ≤ 0.05

SCC


somatic cell count

TBC


total bacterial counts

During the experiment, the number of cows milked per hour was determined in both farms, and the results noted in
successive milkings are presented in Table 3. In
the tandem parlor (F
1
), an average of 7.3 cows were milked per hour
per milking stall. In successive milkings, the number of cows milked per hour reached 7 to 7.6, and no significant di
f-
ferences were noted. In the herringbone parlor (F
2
), 5.7 cows were
milked per hour per milking stall (1.6 cows less than
in F
1
). Similarly to F
2
, no significant differences were observed in successive milkings during which 5.2 to 6 cows were
milked. The results of the study validate the producers' claims that tandem parlo
rs support the milking of a higher nu
m-
ber of cows per hour.


4

The results presented in Table 3, Figure 1 and Figure 2 indicate that total milk sales in farm F
1

varied throughout
2009 from 88,501 kg to 111,032 kg. A more evenly distributed sales volume was noted in farm F
2
. The
sold milk output
in farm F
1

accounted for 1,019,209 kg of milk with an average fat content of 4.14% and an average protein content of
3.29%. Farm F
2

sold 2,955,781 kg of milk with an average fat content of 4.02% and an average protein content of
3.46%. In
F
1
, the highest sales volume was noted in the spring (March, April and May) and summer (August and Se
p-
tember), whereas in F
2
, the highest sales were reported only in the spring (March, April and May). In both analyzed
farms, the above accounted for around
9% of total milk sales in each month. The noted results can be attributed to the
fact that in farm F
1
, the cattle were pasture grazed from May to October, while in F
2

the animals were kept in the barn
throughout the year.












Fig. 1



Total milk production in the studied milkin
g parlors in each month of 2009


In farm F
1
, the highest milk fat content was reported in December (4.42%), and the lowest


in August (3.92%). In
F
2
, the highest fat content was noted in February (4.40%), and th
e lowest


in October (3.82%). In F
1
, the highest pr
o-
tein content was observed in milk produced in October (3.54%), and in F
2



in February (3.51%). The lowest protein
levels in F
1

were determined in July (3.12%), and in F
2



in April (3.31%).

In both farms, SCC never exceeded the allowable norms for premium class milk (PN
-
A
-
86002

1995).

SCC

values
remained fairly constant with no significant differences between the studied farms. In F
1
,
the average SCC reached
278,000/ml, and in F
2



242,000/ml. Elevated SCC values were noted in the summer (July and August) in both farms. A
deterioration in milk quality in the warmest months of the year was also noted by
Danków (2002) and Czaplicka et al.

(1990).














Fig
. 2



Average milk fat content and milk protein content in the studied farms in each month of 2009.


The milk yield and the composition of milk from primiparous cows per 305
-
day lactation period are compared in
Table 3. The
primiparous cows from farm F
2

were characterized by a higher milk yield at 8,467 kg on average, while
the average values noted in F
1

were lower, reaching 7,289 kg. The data presented in Table 3 point to a higher milk yield
of multiparous cows from farm F
2
,

where it reached 9,123 kg on average, in comparison with the average milk yield of
8,143 kg in F
1
.

Mastitis incidence rates in each month of 2009 are presented in Table 4. In farm F
1
, 311 cows were affected by the
disease, while in F
2
, only 88 animals
were diagnosed with mastitis throughout the year. In F
1
, the highest number of
mastitis
-
positive cows was observed in January and February, while in F
2



in the summer months (June, July and A
u-
gust).

Table 4



Mastitis incidence rates (n
umber of mastitis
-
positive cows
) in 2009

Months of 2009

Farm

F
1

F
2

January

44

4

February

46

5

March

25

3

April

18

8

May

27

5

3,5
3,61
3,42
3,31
3,5
3,5
3,34
3,42
3,36
3,38
3,33
3,41
3,38
3,25
3,31
3,21
3,25
3,27
3,12
3,24
3,35
3,54
3,48
3,39
4
4,6
4,26
4,33
4,13
4,2
4,29
4,02
3,94
3,82
3,99
3,78
4,19
4,27
4,35
4,15
4,15
4,1
4,1
3,92
4,04
4,39
4,35
4,28
3
3,5
4
4,5
[kg]
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sep.
Oct.
Nov.
Dec.
Month in 2009
Fat-Ba?dy
Fat-Ba?cyny
Protein-Ba?cyny
Protein-Ba?cyny
163458
179873
183463
189832
185672
170932
175371
176397
166938
168239
167443
159881
92619
88501
110635
103055
101400
91201
95600
115230
111032
91136
90954
90006
0
20000
40000
60000
80000
100000
120000
140000
160000
180000
200000
Milk production
Jan.
Feb.
Mar.
Apr.
May
June
July
Aug.
Sep.
Oct.
Nov.
Dec.
Month in 2009
Ba?dy
Ba?cyny

5

June

24

12

July

26

10

August

25

13

September

16

8

October

11

6

November

21

7

December

28

7

Total

311

88

Mean per month

25.9

7.3

Mean

per cow

1.7

0.4

The highest quantity of milk was produced and sold by farm F
2

due to a higher milk yield and a larger cow popul
a-
tion. The milk from farm F
2

was characterized by a higher protein content and a lower fat content in comparison with
the milk produced by F
1
. An analysis of the correlation between milk composition and cow age pointed to lower fat and
protein levels in the milk of primiparous cows t
han multiparous cows. The milk of primiparous cows bred in farm F
2

was also characterized by a higher fat content and a lower protein content in comparison with F
1

cows. As regards milk
composition, more satisfactory results were noted in the milk of multi
parous cows from farm F
1

than F
2
. Somatic cell
counts were similar in both farms throughout the experiment, and total bacterial counts were elevated in the summer.
Farm F
1

was marked by higher mastitis incidence rates in comparison with F
2
. The above could

be due to less satisfa
c-
tory housing conditions and lower milking hygiene standards in F
1
. The results of this study point to a higher perfo
r-
mance capacity of tandem milking parlors than herringbone parlors, and they are consistent with the parameters quot
ed
by parlor manufacturers.

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