Setting a task of modelling.
There is a cattle herd structured on the basic of age. The herd consists of Heifers,
Calves,
Milk cows,
Cows,
Bulls.
Each Animal
has its Age
. The daily increase depends in weight of an animal which defines the weight of it depends on the age.So, for example, at achievement of the certain age (≈500 days) calves become bulls and pass from Calves
in Bulls
, but not all of them. Only the quantity which is enough for reproduction of the herd. The others remain calves until they fatten the necessary weight (≈1000 kg). As soon as it occurs, they are slaughtered.The similar situation is with heifers. Only at achievement of the certain age (≈450 days) they are divided into two categories: milk cowsand cows. Cows
are bred for meat production, MilkCows - for reproduction of herd and production of milk.According to financial opportunities a farmer defines an initial livestock of the cattle, and then makes a plan of reception of a livestock of the cattle in the future.It is required to model the change of an annual turnover of the herd and its reproduction.
Component of a high level
: Farm (Farm) which describes the structure of the model.
HIGH LEVEL COMPONENT FARM_High
SUBCOMPONENTS
Meteo,
Forage,
Effluent,
Herd
COMPONENT CONNECTIONS
Meteo.sun --> Forage.sun;
Meteo.sun --> Effluent.sun;
Meteo.sun --> Herd.sun;
Herd.Dung --> Effluent.Dung;
Effluent.A --> Herd.A;
Herd.Numb_young --> Forage.Numb_young;
Herd.Numb_old --> Forage.Numb_old;
END OF FARM_High
Basic components
:
1. Meteo which allows to watch the solar activity during a year (it is based on the data of the model Cedar Bog)
DYNAMIC BEHAVIOUR
suns:= 95.9[kJ/m^2] * (1+0.635 * SIN (2[1/d] * Pi *T/365));
WHENEVER T >= TNext DO
sun^:= suns - Oblako;
TNext^:= TNext + 1[d];
END
END OF Meteo
2. Forage. Norms and diets of feeding are defined in it.
DYNAMIC BEHAVIOUR
sun_bio:= sun * Bio_Fac;
WHENEVER T >= TNext DO
TNext^:= TNext +1[d];
Seno^:= 9 * Numb_young + 14 * Numb_old;
Silos^:= 8 * Numb_young + 12 * Numb_old;
Kombicorm^:= 5 * Numb_young + 7 * Numb_old;
Koncentrat^:= 2 * Numb_young + 3 * Numb_old;
Fosfat^:= 0.04 * Numb_young + 0.06 * Numb_old;
Sol^:= 0.03 * Numb_young + 0.05 * Numb_old;
END
DIFFERENTIAL EQUATIONS
p':= sun_bio - 4.03[1/a] * p;
BioMassa':= 0.48[1/a] * p - 17.87[1/a] * BioMassa;
END
END OF Forage
3. Herd, describing variable statuses and dynamics of behaviour of the herd as a whole. The important component which defines the structure of the herd, its internal interaction. It allows to watch a livestock of the herd, its reproduction.
# Changing of weight and age of heifers
WHENEVER (Stage = 1) AND (Index <= NUMBER(Heifers)) DO
Index^:= Index + 1;
Heifers:Animal[Index].Age^:= Heifers:Animal[Index].Age + 1;
Dung^:= Dung + 10;
IF Heifers:Animal[Index].Age < 180 DO
Heifers:Animal[Index].Weight^:= Heifers:Animal[Index].Weight + ves_2;
END
ELSE DO
Heifers:Animal[Index].Weight^:= Heifers:Animal[Index].Weight + ves_3;
END
END
WHENEVER (Stage = 1) AND (Index > NUMBER(Heifers)) DO
Stage^:=2;
Index^:=1;
END
# F
ecundation
of heifers
WHENEVER (Stage = 3) AND (Index <= NUMBER(Heifers)) DO
Index^:= Index + 1;
IF Heifers: Animal [Index].Age > (450 + Norm_raspr(10,3)) DO
IF Rand < 0.85 DO
Heifers^: TO MilkCows SEND Animal[Index]
CHANGING
Age^:=Heifers:Animal[Index].Age;
Weight^:= Heifers:Animal[Index].Weight;
Status^:= TRUE;
Stelnost^:= 1;
END
END
ELSE DO
Heifers^: TO Cows SEND Animal[Index]
CHANGING
Age^:= Heifers:Animal[Index].Age;
Weight^:= Heifers:Animal[Index].Weight;
END
END
END
END
WHENEVER (Stage = 3) AND (Index > NUMBER(Heifers)) DO
Stage^:=4;
Index^:=1;
END
# Calves became Bulls, or they are slaughtered
WHENEVER (Stage = 4) AND (Index <= NUMBER(Calves)) DO
Index^:= Index + 1;
IF (Calves:Animal[Index].Age > (500 + Norm_raspr(10,2)))
AND (NUMBER(Bulls) < 3) DO
Calves^: TO Bulls SEND Animal[Index]
CHANGING
Age^:= Calves:Animal[Index].Age;
Weight^:= Calves:Animal[Index].Weight;
END
END
IF (Calves:Animal[Index].Age > (500 + Norm_raspr(10,2)))
AND (Calves:Animal[Index].Weight > 1000) DO
VesTyw^:= VesTyw + Calves:Animal[Index].Weight/2;
Calves^: REMOVE Animal[Index];
UBOI^:= UBOI + 1;
END
END
WHENEVER (Stage = 4) AND (Index > NUMBER(Calves)) DO
Stage^:=5;
Index^:=1;
END
# Bulls are slaughtered
WHENEVER (Stage = 5) AND (Index <= NUMBER(Bulls)) DO
Index^:= Index + 1;
Bulls:Animal[Index].Age^:= Bulls:Animal[Index].Age + 1;
Dung^:= Dung + 20;
IF Bulls:Animal[Index].Weight < 1000 DO
Bulls:Animal[Index].Weight^:= Bulls:Animal[Index].Weight + ves_3;
END
IF Bulls:Animal[Index].Age > 3000 DO
VesTyw^:= VesTyw + Bulls:Animal[Index].Weight/2;
Bulls^: REMOVE Animal[Index];
UBOI^:= UBOI + 1;
END
END
WHENEVER (Stage = 5) AND (Index > NUMBER(Bulls)) DO
Stage^:=6;
Index^:=1;
END
# B
irth
of young animal
WHENEVER (Stage = 7) AND (Index <= NUMBER(MilkCows)) DO
Index^:= Index + 1;
MilkCows:Animal[Index].Age^:=MilkCows:Animal[Index].Age + 1;
Dung^:= Dung + 20;
IF MilkCows:Animal[Index].Weight < 600 DO
MilkCows:Animal[Index].Weight^:= MilkCows:Animal[Index].Weight + ves_3;
END
MilkCows:Animal[Index].Stelnost^:=
MilkCows:Animal[Index].Stelnost + 1;
IF MilkCows:Animal[Index].Stelnost > (275 + Norm_raspr(5,1))
AND (MilkCows:Animal[Index].Status = TRUE) DO
MilkCows:Animal[Index].Status^:= FALSE;
MilkCows:Animal[Index].Kol_voOtelov^:=
MilkCows:Animal[Index].Kol_voOtelov + 1;
IF Rand < 0.7 DO
Heifers^: ADD 1 NEW Animal
CHANGING
Weight^:= ves_1;
Age^:= 1;
END
END
ELSE DO
Calves^: ADD 1 NEW Animal
CHANGING
Weight^:= ves_1;
Age^:= 1;
END
END
END
# MilkYield
IF (MilkCows:Animal[Index].Kol_voOtelov >= 1)
AND ((MilkCows:Animal[Index].Stelnost < 250) OR
(MilkCows:Animal[Index].Stelnost >280)) DO
NADOI^:= NADOI + 20;
END
# MilkCows are slaughtered
IF MilkCows:Animal[Index].Kol_voOtelov > 5 DO
VesTyw^:= VesTyw + MilkCows:Animal[Index].Weight/2;
MilkCows^: REMOVE Animal[Index];
UBOI^:= UBOI + 1;
END
END
WHENEVER (Stage = 7) AND (Index > NUMBER(MilkCows)) DO
Stage^:=8;
Index^:=1;
END
#
F
ecundation
of MilkCows
WHENEVER (Stage = 8) AND (Index <= NUMBER(MilkCows)) DO
Index^:= Index + 1;
IF (MilkCows:Animal[Index].Status = FALSE) AND
(MilkCows:Animal[Index].Stelnost > (340)) DO
IF Rand < 0.98 DO
MilkCows:Animal[Index].Status^:= TRUE;
MilkCows:Animal[Index].Stelnost^:= 1;
END
ELSE DO
MilkCows^: TO Cows SEND Animal[Index]
CHANGING
Age^:= MilkCows:Animal[Index].Age;
Weight^:= MilkCows:Animal[Index].Weight;
END
END
END
END
END OF Herd
4. Effluent (Drains) in which it is provided annual downcast drains on fields (for fertilizer of pastures). Also sale of drains for the manufacture of mineral fertilizers is possible.
DYNAMIC BEHAVIOUR
WHENEVER T >= TNext DO
TNext^:= TNext + 1[d];
IF ((sun > 100[kJ/m^2]) AND (sun < 110[kJ/m^2])) AND (FLAG = TRUE)
AND (Dung >= 10000) DO
A^:= 0;
FLAG^:= FALSE;
END
END
WHENEVER (T >= TNext) AND (FLAG = FALSE) DO
IF (sun > 50[kJ/m^2]) AND (sun < 60[kJ/m^2]) DO
FLAG^:= TRUE;
END
END
END OF Effluent
5. Profit, expenses (profit, expenses), including an economic part of the model. Unfortunately, because of insufficient amount of the information it is designed only in the theory. But further, at the profound studying of the model, it will be created and, I hope, it will work on a level with other components of the model.
MOBILE COMPONENT Animal
DECLARATION OF ELEMENTS
STATE VARIABLES
DISCRETE
Age (INTEGER):= 0,
Weight (REAL):= 0,
Status (LOGICAL):= FALSE, # Fecundation / not Fecundation
Stelnost (INTEGER):= 0, # Duration of the pregnancy
Kol_voOtelov (INTEGER):= 0, # Number of calves
MilkYield (REAL):= 0,
Manure (REAL):= 0
END OF Animal
The results of modelling with an initial livestock of the cattle - 30 heifers, 10 calves (all animals are about one year):
On the given schedules dynamics of transition of animals from one age groups in others is displayed.
We can see, that at achievement of the certain age heifers (a red line) are divided into two categories: milk cows (a green line) and cows (a blue line). Cows fatten the necessary weight, and then they are slaughtered. Through the certain time interval Milk cows give a gain of the herd and start to be milked.
We can see, that at achievement of the certain age three calves (a red line) become bulls (a blue line), the others remain calves, until they fatten the necessary weight. As soon as it occurs, they are slaughtered.
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