Pig Flow Models

Dr John Carr

Murdoch University and Portec Australia

 

The easiest pig flow model to set is when the farm is still on the drawing board.  The aim of pig farming is to achieve production at a minimal cost given the opportunities.  Maintaining health contributes significantly to reducing the cost of production and the only way to resolve and maintain health is to achieve absolute all-in/all-out.

 

Unfortunately, the pig industry will cheat on all-in/all-out, (from time to time) and then hopes to “get away” without issues.  However, nature has a way of making the farm pay.  The more cheating that occurs, the more desperate cleaning protocols become, rooms are not rested and the pigs are overstocked or under-stocked, continuous flow starts or the equally ludicrous all-out only programme.  Health issues then occur, resulting in failure of growth and ventilation systems – the farm is on a negative health spiral.

 

 Farms generally need to take a long hard look at their layout and design a layout that will:

 

Of course new farms are a novelty.  Farms grow and while the farm was built with an ideal pig flow, with time new buildings are added, without pig flow being a consideration.  The chaos then starts to build up.

 

All farms batch

Many producers think that batching is just a term used by small farms.  However, to achieve all-in/all-out all farms must batch.  It just depends on what time interval the producer turns the farm.  The most common batches are:

Half a week

Once a week

Every two weeks

Every three weeks

 

Which weaning age should I pick?

Within the European Union, there is little real choice as it is illegal to wean before 21 days of age.  The weaning age should be determined by the quality of the nursery and available feeds.  A lactation shorter than 19 days reduces parity 1 sow production, lactations shorter than 17 days reduce parity 2 sow production – that is half the females on a normal parity structure herd.  Sows older than parity 3 do not generally suffer a production reduction with short lactations.

In the rest of the world such restrictions are not mandatory.

 

Table 1

The age range of piglets at weaning   (Assuming weekly weaning)

Weaning system

Minimum age

Maximum age

Average

3 weeks

14 days

21 days

18 days

3 weeks 2x week

17 days

21 days

19 days

4 weeks

21 days

28 days

24 days

5 weeks

28 days

35 days

31 days

7 weeks

42 days

49 days

45 days

 

One way to assess if a farm weaning weekly is adopting a formal all-in/all-out programme is to examine the average weaning age.  Many textbooks and papers discuss increasing weaning age by a day or two and the advantages this will invoke in your herd, but with weekly weaning, the weaning age can only move by 7 whole days – unless you change the day of the week you wean – which farms do not do.  If you move to twice a week weaning, you reduce the group size at weaning which often results in a loss of all-in/all-out in the wean to finish area.

 

Designing a pig flow model -Where should you start?

The finishing floor area should be the starting point.  Unfortunately, many farms adopt a variety of finishing systems with different sizes and pen layouts.  In addition, many farms have no idea of the size of the unobstructed floor area available for their pigs.

Therefore, in practice, the farrowing area is a good start and allows the farm to at least achieve all-in/all-out to the point of weaning.  If you do not practice all-in/all-out by weaning – you do not practice all-in/all-out anywhere.

 

What matters in the farrowing area?

To adopt all-in/all-out programme the farm needs to create equal batches of sows within a recognized time period (the BATCH).  The farm therefore needs to know

 

Should I wean twice a week or every 5 weeks?

The answer to this question should be determined by the size of your nursery accommodation which allows for all-in/all-out.

 

Table 2

Approximate herd size to produce a set number of weaners per batch

Batch time

0.5w

1w

2w

3w

5w

In weeks

Weaners/batch

to allow for

all-in/all-out

 

Herd size (approximate)

Sows/batch

50

260

130

65

45

30

5

100

520

260

130

90

55

10

200

1030

520

260

180

110

20

400

2060

1030

520

350

210

40

500

2570

1290

650

430

260

50

1000

5150

2570

1290

860

520

100

Excel spreadsheet  xls file   (for the excel file right click save as file)

The alternative method is to examine the layout of the farrowing area and decided how the space can be best utilized to produce a reasonable result.

 

Table 3

Number of rooms required to allow for all-in/all-out

Batch time

0.5w

1w

10d

2w

3w

4w

Weaning age

 

 

 

 

 

 

3 weeks

8

4

 

2

 

1

4 weeks

10

5

3

 

2

 

5 weeks

 

6

 

3

 

 

0.5w+ is weaning with the minimum weaning age is 17 days.

Spreadsheet  xls file (for the excel file right click save as file)

 

Note several models will not work over the 52 calendar weeks or groups do not align.

For example mated sows will farrow 115 days later but a farrowing crate is not available.

 

This can be illustrated graphically – excel spread sheet   (for the excel file right click save as file)

In all the figures the following colour codes apply:

Colour code

 

Sow move in

 

Lactation

 

Cleaning

 

Possible nursery /otherwise empty

The plans are designed around Monday and Thursday weaning for the 0.5 week batch and Thursday weaning for the other batch models.

 

Figure 1

3 week weaning room layout designs – Note these are illegal within the European Union

Batch 0.5 week

 

 

 

 

 

 

Batch 1 week

 

Batch 2 weeks

Batch 4 weeks

Day

Room Number

 

Room Number

 

Rooms

 

Room

 

 

 

1

2

3

4

5

6

7

8

1

 

1

2

3

4

1

 

1

2

1

 

1

1

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2

4 week weaning room layout designs

Batch 0.5 week

Batch 1 week

Day

Room Number

 

 

Room Number

 

1

2

3

4

5

6

7

8

9

10

1

1

2

3

4

5

1

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4 week weaning room layout designs continued

 

Batch 10 days

      

Batch 3 week

Day

Room Number

Rooms

 

1

2

3

1

1

2

1

Monday

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

Monday

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

Monday

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

Figure 3

5 week weaning room layout designs

Batch 1 week

Batch 2 week

Day

Room Number

Room Number

1

2

3

4

5

6

1

1

2

3

1

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

Thursday

 

 

 

 

 

 

 

 

 

 

 

Monday

 

 

 

 

 

 

 

 

 

 

 

 

Pig Flow models

The farm can then designed around the farrowing area with estimations made for the space required for each group.

 

Table 4

Example of the number of groups required dependent on the pig flow model

 

Batch time

 3 week weaning

4 week weaning

5 week weaning

 

0.5

1

2

4

0.5

1

1.5

3

1

2

weeks

Gilt introduction

9 weeks intro.

18

9

5

3

18

9

6

3

9

5

 

Gestation groups

16 weeks

32

16

8

4

32

16

11

6

16

8

 

Farrowing groups

variable

8

4

2

1

10

5

3

2

6

3

 

Nursery groups to

10 weeks old

14

7

4

2

12

6

4

2

5

3

 

Finish groups to

24 week of age

28

14

7

4

28

14

10

5

14

7

 

The farrowing groups have variable batch time dependent on the weaning age.

 Spreadsheet   xls file (right click and save  target as)

 

Once the farm team has determined the number of groups required in each section, the number of animals that will be in each group can be easily calculated.

 

Table 5

Minimum targets for pig production

Animal Group:

 

Calculation (using Excel notations)

Gilts pool requirement

 

= (BF/10)*( # weeks introduction)/batch time in weeks

Breeding females required per batch

BF

=Roundup (FS/Farrowing rate %)

Farrowing sows per batch

FS

 

Numbers weaned per batch

WB

= Rounddown (FS * Numbers weaned per crate)

Numbers sold per batch

 

= Rounddown ((WB)/(1-post-weaning mortality %) *(52/batch time in weeks))

 

Spreadsheet xls file (right click and save target as)

 

Table 6

Example of farm pig flow models

Assumptions: 10 weaned per crate, 84% farrowing rate, 95% production post-weaning* and a 9 week gilt introduction programme using a one week batch programme.

Minimum number of animals in each category

Gilts pool requirement

6

11

22

33

44

54

Breeding females required per batch

6

12

24

36

48

60

Farrowing sows per batch

5

10

20

30

40

50

Numbers weaned per batch

50

100

200

300

400

500

Numbers sold per batch

48

95

190

285

380

475

* post-weaning pigs with a saleable value – remaining pigs after post-weaning mortality and culls removed.

 

 

Pig Flow calendars

Once a model is agreed then calendars of events can be constructed for all parts of the farm.

 

Table 7

Daily events in the adult herd for 2 months

The example herd used a 3 week batch 4 week weaning programme

The group identification (number) starts with the service group and ends with the finished pigs at market

2009

Batch time

3 weeks

Weaning age

4 weeks

 

Month

 

Monday

Tuesday

Wednesday

Thursday

Friday

Saturday

Sunday

 

Event

W

D

 

D

Service G

D

 

D

Wean G

D

Farrow G

D

 

D

 

January

1

29

 

30

S1

31

 

1

 

2

 

3

 

4

 

 

2

5

 

6

 

7

 

8

 

9

F3

10

 

11

 

 

3

12

 

13

 

14

 

15

W2

16

 

17

 

18

 

 

4

19

 

20

S2

21

 

22

 

23

 

24

 

25

 

 

5

26

 

27

 

28

 

29

 

30

F4

31

 

1

 

February

6

2

 

3

 

4

 

5

W3

6

 

7

 

8

 

 

7

9

 

10

S3

11

 

12

 

13

 

14

 

15

 

 

8

16

 

17

 

18

 

19

 

20

F5

21

 

22

 

 

9

23

 

24

 

25

 

26

W4

27

 

28

 

29

 

W= week.  D= day. G = group number

 

Table 8

Weekly events in the grow/finish herd in the same herd as table 5

The numbers in the table indicate which group of pigs are at which weight, group identification starts with the breeding sows and gilts at mating.

 

2009

Batch time 3 week

Wean    4 week

Month

 

10 week

12 week

15 week

20 week

24 week

Event

W

30 kg

45 kg

60 kg

95 kg

110 kg

January

1

G6

 

 

 

 

 

2

 

 

 

G3

 

 

3

 

G6

G5

 

G1

 

4

G7

 

 

 

 

 

5

 

 

 

G4

 

February

6

 

G7

G6

 

G2

 

7

G1

 

 

 

 

 

8

 

 

 

G5

 

 

9

 

G1

G7

 

G3

W= week.  D= day. G = group number

 

Pig Flow calendars:  Pig Flow Calendars General

 

Batch

Weaning age

0.5 week

3 week

1 week

2 week

4 week

0.5 week

4 week

1 week

10 days

3 week

1 week

5 week

3 week

6 week

7 weeks

Example of flows which will work with adjustments (for example)

4 week

4 week

 

 

Table 9

Stockperson routines around a pig flow model

 

The table below indicates which group of pigs require a specific task

This work sheet is designed for weaning once every three weeks at 4 weeks of age

                                                                                                                                                                                                                                                                                          

Task               Week

 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

Move wean sows

 

 

2

 

 

3

 

 

4

 

 

5

 

 

6

 

 

7

 

 

1

 

 

2

 

 

Breed

1

 

 

2

 

 

3

 

 

4

 

 

5

 

 

6

 

 

7

 

 

1

 

 

2

 

Heat Check 1

7

 

 

1

 

 

2

 

 

3

 

 

4

 

 

5

 

 

6

 

 

7

 

 

 1

 

Heat check 2

 

7

 

 

1

 

 

2

 

 

3

 

 

4

 

 

5

 

 

6

 

 

7

 

 

1

Condition score sows

 

 

+

 

 

+

 

 

+

 

 

+

 

 

+

 

 

+

 

 

+

 

 

+

 

 

Vaccinate 1 (6 weeks)

 

5

 

 

6

 

 

7

 

 

1

 

 

2

 

 

3

 

 

4

 

 

5

 

 

6

Vaccinate 2 (3 weeks)

 

4

 

 

5

 

 

6

 

 

7

 

 

1

 

 

2

 

 

3

 

 

4

 

 

5

Move into farrow

3

 

 

4

 

 

5

 

 

6

 

 

7

 

 

1

 

 

2

 

 

3

 

 

4

 

Boars to vaccinate

+