Evaluation and optimization of milking in some polish dairy farms differed in milking parlours

Abstract

Farms are continuously growing and modernized in Poland during the last years. The increased dairy herds require also modernization of milking equipment. The aim of this paper was to present the main criteria, which could be used for the solution of principal questions important for the choosing, optimization and evaluation of milking parlours in conditions of Polish agriculture. The research was conducted on three modern dairy farms in Poland to assess effectiveness of different milking parlours use. The first farm with 60 cows was equipped by side by side milking parlour, the second farm with 85 cows was equipped by herringbone milking parlour and the third farm had 80 cows and autotandem milking parlour. The choosing and evaluation of milking parlours parameters were based on the available information and results of previous research in dairy farms in the Poland, using the mathematical model created in the Czech Republic. Time for milking and final specific direct costs were main parameters which enable evaluation and choosing of suitable milking parlour for the dairy farm. The results of measurement and calculation in current farms were compared with possible future enlarged farms to capacity of 200 cows.

Full text

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Agronomy Research 15(1), 112–122, 2017
Evaluation and optimization of milking in some Polish dairy
farms differed in milking parlours
M. Gaworski1,*, N. Kamińska1 and P. Kic2
1Warsaw University of Life Sciences, Department of Production Management and
Engineering, Nowoursynowska str. 164, PL02-787 Warsaw, Poland
2Czech University of Life Sciences Prague, Faculty of Engineering, Department of
Technological Equipment of Buildings, Kamycka 129, CZ165 21 Prague 6,
Czech Republic
*Correspondence: marek_gaworski@sggw.pl
Abstract. Farms are continuously growing and modernized in Poland during the last years. The
increased dairy herds require also modernization of milking equipment. The aim of this paper
was to present the main criteria, which could be used for the solution of principal questions
important for the choosing, optimization and evaluation of milking parlours in conditions of
Polish agriculture. The research was conducted on three modern dairy farms in Poland to assess
effectiveness of different milking parlours use. The first farm with 60 cows was equipped by side
by side milking parlour, the second farm with 85 cows was equipped by herringbone milking
parlour and the third farm had 80 cows and autotandem milking parlour. The choosing and
evaluation of milking parlours parameters were based on the available information and results of
previous research in dairy farms in the Poland, using the mathematical model created in the Czech
Republic. Time for milking and final specific direct costs were main parameters which enable
evaluation and choosing of suitable milking parlour for the dairy farm. The results of
measurement and calculation in current farms were compared with possible future enlarged farms
to capacity of 200 cows.
Key words: milking parlours, dairy farms, costs, cows, milking process.
INTRODUCTION
Livestock production in countries with intensive agriculture is undergoing big and
rapid changes. Number of farms are expanding and increasing the average annual milk
production per cow. These factors lead to modernization of milking equipment.
European housing systems are steadily changing from tied barns towards loose barns
and larger herd sizes (Maton et al., 1985; Bottema, 1992; Hansen, 1999; Bieda & Herbut,
2007; Gaworski et al., 2013; Gaworski & Leola, 2014; Gaworski & Priekulis, 2014;
Gaworski & Priekulis, 2015). Due to these changes, many dairy farmers will have to
design and build new milking parlour systems.
The milking process is the key operation on dairy farms. The function of milking
parlour is one of the factors which affect the efficiency of milk production on the farm.
There are many problems which influence the choosing and proper use of milking

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parlour. Some of them should be solved in advance during the preparation and design of
dairy farm.
Modern large-scale farms require appropriate modern technical equipment.
Equipment producers want very often to sell farmers the most expensive product which
is not always appropriate. Operation is affected e.g. by selected number of milking stalls,
by high or low number of milkers, sometimes by incorrectly selected or by choosing
insufficient automation equipment. Therefore, it is important to compare different
possibilities of milking parlours and try to find the strengths and weaknesses of some
proposals. Model calculations allow comparing options and making decision taking into
account the accurate and uniform criteria correctly according to the results of
calculations.
The same milking parlours have different operating conditions in different
countries around the world. Dairy farms in Poland are interesting, because traditional
small farms are rapidly growing and milking technology should be modernized. For
these farms it seems to be useful to calculate (model in advance) different variants of
equipment and operating conditions by precisely selected and uniform criteria. The
objective of the paper was to present the main criteria, which could be used for the
solution of principal questions important for the choosing, optimization and evaluation
of milking parlours in conditions of Polish agriculture.
MATERIALS AND METHODS
Many books, reports and scientific publications present results of research and
recommendations focused on the problems of AMS (automatic milking system), usually
also including comparison of AMS and milking parlours, in some publications
information related to problems of performance and economic analysis (Bottema, 1992;
Kic & Nehasilova, 1997; Kic, 1998; Priekulis & Laurs, 2012).
Leading companies producing milking equipment usually offer a variety of
constructions of milking parlours recommended for different number of cows on the
farm. They also recommend the possible level of automation and number of milkers
which should work in the milking process (Brunsch et al., 1996; Dolezal et al., 2000;
Chiumenti, 2004). But there are rather big differences in local conditions of the farms
according to the production, economic, market and labour situation of the country or
province. Although the use of AMS for large farms with a big capacity is developing,
the high cost of this solution discourages many farmers. The question for medium and
large farms is to currently choose an appropriate type of milking parlour.
It is possible to say that there are two divergent interests and goals in choosing the
appropriate type of milking parlour. On the one hand there is interest of manufacturer
and dealer who strives for the highest price contract and on the other hand, a farmer who
would like to receive the best parlour, but for the price as favourable as possible, i.e. the
lowest investment costs.
There are various practical recommendations in the literature, however, there are
usually not sub-economic data included which result in a specific numerical data,
characterizing the overall result of milking parlour solutions. Some publications
(Provolo, 1992; Provolo & Marcon, 1993) present models focused on the choosing of
milking parlours, but not in a complete universal approach which could be adapted
everywhere. Results of research and basic equations used for calculation of several

114
parameters of milking parlours are presented by Gaworski & Priekulis (2014). Similar
calculations, completed with several important economic results which are valid for
rotary milking parlours are presented by Ozolins et al. (2012).
The question is which criteria would be suitable to determine the type of milking
parlour for each farm. If we know them, according to them can be evaluated different
milking parlours, as well as we follow them when consider specific aspects and
individual issues which influence the selection of milking parlour for the farm.
For objective assessment and selection of milking parlours there can be used and
considered a lot of different aspects, e.g.: animal welfare and ventilation system (Herbut
et al., 2012; Herbut & Angrecka, 2015; Herbut et al., 2015), capacity, price, the number
of milkers, the complexity and sophistication of the operation, reliability, the dimensions
(Gómez et al., 2017) and complicated installation in the building, demand of
maintenance and service, and some other aspects like producer satisfaction (Wagner et
al., 2001).
Overestimating or underestimating some aspects may result in problems during the
normal operation of the milking parlour in practice and thus negatively affect the
operation of the farm. In some cases this may lead to unnecessary wastage of finance for
investment, without any real benefit to the operation of the farm.
To develop problem concerning evaluation of milking process, three farms typical
for current situation in the Polish conditions were included in the investigations. All data
used for the calculation were based on the data from modern dairy farms in the Poland.
The Farm 1 with 60 cows was equipped by side by side milking parlour (2 × 5). The
Farm 2 with 85 cows was equipped by herringbone milking parlour (2 × 7) and the
Farm 3 had 80 cows and autotandem milking parlour (2 × 3). The investigated dairy
farms were under milk recording system. The following annual milk yield per cow was
identified in particular farms (in kg cow-1 year-1): 8,400 (Farm 1), 8,700 (Farm 2) and
8,200 (Farm 3). In all farms cow herds weren’t divided into technological groups. The
Holstein Friesians breed of dairy cattle was kept in all investigated farms.
There were calculated criteria and compared results between current situation and
future, when increased herd size of all three farms would be 200 cows.
The first criterion which is important for the function of the farm is the time for
milking. The fast milking of all cows enables to have enough free time in which cows
have the opportunity to take feed and relax, to go to pasture and so on. The duration of
one real milking of all cows can be calculated according to the equation (1).
pr
LS
vd
T
Q
N
T+=
(1)
where: Tvd – the duration of one real milking, min; N – the number of lactating cows on
the farm, cow; QLS – the real capacity of a milking parlour, cow min-1; Tpr – the time of
working breaks, min.
As regards of a human working process and working operations there is important
the total time of duration of one milking including preparatory operations and finishing
work after milking, calculated according to the equation (2).

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cpvdcd TTTT ++=
(2)
where: Tcd – the total time of duration of one milking including preparatory operations
and finishing work after milking, min; Tp – the time of preparatory work before milking,
min; Tc – the time of finishing and cleaning work after milking, min.
When this period Tcd is short enough then there is enough time for workers (milkers)
to carry out the other activities (feed preparation, cleaning, control of animals etc.).
Therefore the time should be a criterion for optimization and the selection of a suitable
milking parlour for the farm.
The second decisive criterion for choosing the appropriate milking parlour should
be the economic criteria. It is necessary to compare the specific data, which are in this
case the final specific direct costs of a milking parlour per cow and year uCMP, which are
calculated according to the equation (3) as a sum of specific labour costs of milking per
cow and year uCW, specific costs of the milking equipment per cow and year uCP and
specific costs uCS of consumed supplies.
These specific costs are sum of many individual parameters, which presentation is
not the aim of this paper, mainly because of the extent. Specific labour costs of milking
per cow and year uCW are based on the labour need per cow per year and the average
salary of milker, specific costs of the milking equipment per cow and year uCP are
including the annual percentage of technique depreciation, annual percentage
depreciation of parlour building and specific repair costs expressed and calculated by a
coefficient of repairs. Specific costs uCS of consumed supplies are including sum of the
cost of electricity, water for washing, chemicals for cleaning, disinfectants and towels
needed during the milking.
S
u
P
u
W
u
MP
u
CCCC ++=
(3)
where: uCMP – the final specific direct costs of milking parlour, EUR cow-1 year-1;
uCW – the specific labour costs per cow and year, EUR cow-1 year-1; uCP – the specific
costs of the milking equipment, EUR cow-1 year-1; uCS – the specific costs of consumed
supplies, EUR cow-1 year-1.
Specific labour costs uCW are calculated on the basis of labour requirements per cow
per year Tr (h cow-1 year-1) calculated by using equation (4) and average hourly wage of
the milker. The labour requirement Td can be used by equation (5).
60
365 d
r
T
T×
=
(4)
where: Tr – the labour requirement for milking per cow per year, h cow-1 year-1;
Td – the labour requirement during milking per cow per day, min cow-1 day-1.
ú
ú
û
ù
ê
ê
ë
é×+++×
×=
N
nTtttN
iT
dsprcprc
d
)(
(5)
where: i – the number of milking per day, day-1; trc – the average net labour requirement
for milking per cow, min cow-1; tp – the time of preparatory work before milking
calculated per one cow, min cow-1; tc – the time of finishing and cleaning work after
milking calculated per one cow, min cow-1; nds – the real number of milkers, pers.

116
Specific costs of the milking equipment uCP are calculated as specific data of total
operating costs of the milking machine converted per one cow. Therefore it includes the
amortization of machinery, which is the purchase price of the machine expressed by
percentage of machine amortization, further amortization of construction that includes
construction costs and percentage of building amortization and the cost of servicing,
maintenance and repairs, which are usually expressed as a percentage of planned
acquisition costs.
Specific costs of consumed supplies uCS are calculated as a sum of costs of all
necessary operating materials and energy. The consumption of electricity is proportional
to the power inputs of motors and all electrical appliances of milking parlour during
their operation, water, disinfection etc. All is re-calculated per cow and year
(EUR cow-1 year-1).
The real number of milkers for the whole farm nds is the rounded integer nd. The
theoretical required number of milkers nd is based on the calculation of equation (6).
d
PL
dW
Q
n=
(6)
where: nd – the theoretical required number of milkers per one parlour, pers.; QPL – the
required capacity of the milking parlour, cow min-1; Wd – the working capacity of one
milker, cow min-1 pers-1.
The maximum reasonable number of milkers per a parlour ndm is a criterion to avoid
the idle time or complicated work of milkers. It is calculated by the number of milking
stalls mZ divided by the number of clusters ns that can operate one milker.
s
Z
dm n
m
n=
(7)
where: ndm – the maximum number of milkers per one parlour, pers.; mZ – the number of
milking stalls in milking parlour, pcs; ns – the maximal number of clusters per milker,
pcs.
An important technical parameter is the theoretical number of milking stalls in a
parlour mT, calculated by using equation (8).
)(
vdPLT
ttQm +×=
(8)
where: mT – the theoretical number of cows which are in milking parlour in one moment
(this corresponds to theoretical number of milking stalls in parlour), pcs; td – the average
duration of milking by milking machine per one cow, min; tv – the average idle time of
a cluster, min.
msnv tttt ++=
(9)
where: tn – the average time for cluster attachment, min; ts – the average time to remove
the cluster, min; tm – the average time for manipulation with cluster, min.
RESULTS AND DISCUSSION
The results of calculations of current situation at the Farm 1–3, including the
abovementioned data on annual milk yield per cow and the others were presented on the
Figs 1–3. Two milkers were supposed to work in all variants of milking parlours at all

117
three Farms. There was a standard level of technical equipment in all variants of milking
parlours.
Figure 1. Current time of one milking in dairy Farm 1 (side by side milking parlour), Farm 2
(herringbone milking parlour) and Farm 3 (autotandem milking parlour).
The aim the Fig. 1 was to show the whole time of one milking, which is important
for farmer from practical point of view. It is comparable with the results of bigger farm
(200 cows) presented in the Fig. 4.
The data concerning time of one milking (Fig. 1) were usable to propose and
calculate the index of milking stall load per cow. In order to find the index value, the
time of milking was multiplied by number of milking stalls (in the milking parlour) and
divided by number of cows in the farm (herd). Differences in the index values for
investigated dairy farms were presented in the Fig. 2.
Figure 2. Index of milking stall load for three type of milking parlours in the investigated dairy
farms.
The index of milking stall load shows the lowest value for autotandem type of
milking parlour. Such result confirms that cow milking in individual stalls like
autotanded can reduce time spent by each animal in milking parlour. The side by side
and herringbone milking parlours include group milking so as a result it is possible to

118
indicate longer time spent by each cow in milking stall. It can be suggested that higher
number of stalls in herringbone milking parlour (14 stalls) decide about higher index of
milking stall load in comparison with the index calculated for side by side milking
parlour (10 stalls). The lower values of the index of milking stall load can identify shorter
time spent by cows in milking parlour and such situation would be recognized as a more
comfortable for animals.
Figure 3. Specific costs of milking in the milking parlours in current situation in dairy Farm 1
(60 cows, side by side milking parlour), Farm 2 (85 cows, herringbone milking parlour), Farm 3
(80 cows, autotandem milking parlour).
The variant in Farm 1 (60 cows) with milking parlour side by side 2 × 5 milking
stalls has rather good labour productivity as well as sufficient milking capacity therefore
the labour requirements are not too high in this variant and the time of one milking
(Fig. 1) is shorter than in the Farm 2 (85 cows) with herringbone milking parlour 2 × 7
and shorter than in the Farm 3 (80 cows) autotandem milking parlour 2 × 3. On the other
side milking parlour in the Farms 3 is cheaper (uCP), which results in the lower final
specific direct costs of milking parlour uCMP (Fig. 3).
The evaluation of current milking conditions is a background for calculations of
future situation in all farms with increased number 200 cows. There are calculated and
checked some basic principle parameters.
The real values of number of milking stalls in a parlour mZ and real number of
milkers nds, the theoretical number of milking stalls in a parlour mT according to the
equation (8), the theoretical required number of milkers nd based on the calculation of
equation (6) and the maximum reasonable number of milkers per a parlour ndm according
to the equation (7) are presented in the Table 1.
Table 1. Real and theoretical values of main parameters of milking parlours in the Farms 1–3
Parameter
Farm 1
Farm 2
Farm 3
mZ
10
14
6
mT
21
18
10
nds
2
2
2
ndm
1.3
2
1.5
nd
2.8
2.6
2.6
Explanation: mZ – the number of milking stalls in milking parlour; mT – the theoretical number of milking
stalls in parlour; nds – the real number of milkers; ndm – the maximum number of milkers per one parlour;
nd – the theoretical required number of milkers per one parlour.

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The theoretical values are calculated with respect to the current duration of one real
milking time Tvd and the total time of duration of one milking including preparatory
operations and finishing work after milking Tcd.
Calculated numbers of milking stalls mT which should be in the milking parlours in
farms with future capacity 200 cows are in all Farms 1–3 bigger than real number of
milking stalls mZ in currently used milking parlours. It means that the time of milking
will be longer. It is confirmed by results presented in the Fig. 3. Number of milkers nds
should be theoretically higher (nd), but on the other hand the maximum reasonable
number of milkers per a parlour ndm is lower. In the case of the Farms 1 and 2 it is even
lower than currently working milkers ndm.
The results of calculations of the farms with increased future herd size to 200 cows
are presented on the Figs 4 and 5. The time per one milking is increased and differences
between three milking parlours are more obvious (Fig. 4). The variant at Farm 1 with
milking parlour Side by Side 2 × 5 milking stalls is thanks to good labour productivity
as well as sufficient milking capacity still acceptable as the time of one milking which
can be expected (2.5 h) is shorter than in the Farm 2 (3 h) with herringbone milking
parlour 2 × 7 and shorten than in the Farm 3 (4.5 h) autotandem milking parlour 2 × 3.
Figure 4. Time of one milking at dairy Farm 1, Farm 2, Farm 3 in future with 200 cows.
Figure 5. Specific costs of milking at dairy Farm 1, Farm 2, Farm 3 in future with 200 cows.

120
The final specific direct costs uCMP of milking calculated per one cow and year
(Fig. 5) are dramatically lower than the current situation in all three farms (Fig. 3). It
looks that the best results are achieved in the Farm 1, equipped with the milking parlour
Side by Side 2 × 5 milking stalls. Specific direct costs are rather low and the time of
milking is the shortest from all three studied farms. The Farm 3 has slightly lower
specific direct costs, but time of milking is very long; it could complicate the
organization of all technological activities in the farm during the whole day. In the case
of increased capacity of farms it is recommendable to modernise the milking parlour and
install the new one with bigger capacity. The final decision of choosing the suitable
milking parlour will depend on the priorities of the farmer, if he prefers cheaper solution
or more expensive variant but with higher capacity and shorter time of milking.
Currently there are a variety of mathematical models, including stochastic models
(Nitzan et al., 2006) which can help us to optimize the solution of various functional
dependencies. It is always necessary to find appropriate criteria for the decision-making
process. Some results of optimization and calculation based on mathematical model
focused on the conditions of dairy farms and milking production in Czech Republic
presented by Kic (2015a, 2015b) constitute one of the examples to develop some
considerations concerning increase in milking effectiveness.
CONCLUSIONS
The time for milking and the final specific direct costs are the main parameters
which enable evaluation and choosing of suitable milking parlour for the dairy farm.
Both previous mentioned parameters in proposed methodology include the main
technical parameters, indicators of labour productivity and economic criteria which can
be used for determination of optimal parameters of milking parlour.
Calculation for all evaluated farms showed that the increased capacity from current
situation (60, 85 and 80 cows) to the capacity 200 cows brings significantly lower final
specific direct costs of milking parlour (reduction about 40% in the Farm 1, about 48%
in the Farm and about 41% in the Farm 3). The time of one milking at all dairy farms is
significantly increased; the biggest extension of milking time is in the farm equipped
with the smallest milking parlour (Farm 3).
It is advantage that the calculation using this model allows, unlike the calculations
solved earlier by other authors, to change all basic parameters of the construction and
operation of the milking parlour on dairy farms. The preliminary calculations in the
preparatory phase before developing a project enable to evaluate (positives and
negatives) various solutions of milking parlours. The evaluation of existing milking
parlours in the farms can help to improve the milking process and operations from the
point of view of either technical improvement or improved activity of milkers, especially
for the future development of farms.
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