Production planning

Pig production is like any other business; without clear objectives and production targets, it lacks purpose and can end up being less profitable than it could be.

Loss of profit from not working to a production plan can be caused by under or overstocking, empty pens, incorrect selling weights and unbalanced sow numbers. The losses on each pig sold soon add up.

Benefits of production planning

Production planning means developing a work schedule that makes best use of all the pens in the piggery. It balances sow productivity with grower-shed capacity to maximise return on your investment.

A production plan is based on the assumption that profitability depends on the:

  • amount of pig meat sold each year
  • average price for sale of pig meat
  • cost of production.

It involves setting targets for the number of pigs sold, pigs weaned, litters born and sows mated per week to make the best use of piggery buildings.

Measurements of efficiency such as the number of litters per sow a year, litter size, feed conversion ratios, etc. are more about reducing operating costs.

Planning can lift profits by increasing the amount of pig meat produced without changing production efficiency measures. This page shows you how to plan on paper; however, there are software programs that can also assist in planning and determining the most profitable sale weight, such as AUSPIG.

Developing a plan

Step 1: Calculating grower shed throughput capacity

Start by working out the space available in the weaner pens through to the finisher pens; space determines a piggery's throughput capacity. ('Grower sheds' refers to all sheds that house pigs from weaning to sale.) Don't start a production plan based on a particular number of sows or farrowing pens as this approach is more likely to result in less profitable selling weights.

Start by determining the target number of pigs that can be put through the grower space each week to keep the sheds fully occupied, and with the pigs sold at the most profitable weight.

  • Draw a floor plan of the grower sheds with the measurements on all pens.
  • Calculate the living space in each pen and the total space available (exclude space taken up by feeders).

Example: Total living space is 440 m²

  • Decide the most profitable selling weight and base your production plan on this target. Mostly this will be between 85 and 110 kg liveweight unless the market is offering a healthy premium for other weights. The optimum baconer weight for gilts may be less than that for boars.
  • Assume the target selling weight is an average of 94 kg liveweight, with gilts being slightly lighter and boars heavier.
  • Determine the age of pigs at the target selling weight, and the time spent in grower sheds, based on the growth rate being achieved in the piggery now.

With a growth rate of 560 g per day from birth to a target selling weight of 94 kg, pigs will be sold at an average of 24 weeks of age. With a weaning age of four weeks, they spend 20 weeks in the weaner to finisher sheds (24-4= 20).  Work out how many grower pigs the piggery can hold. Assume the average pig takes up 0.5 m² of living space. If you want to allow for 'empty pen' time between moving pigs, use a figure of 0.55 m² per pig. For more accurate planning, do the calculations for the number of pigs at each stage, with their respective space needs.

With 440 m² of living space and allowing 0.5 m² per pig, the piggery can accommodate 880 growers (440 ÷ 0.5 = 880).  The throughput capacity of the grower sheds can now be calculated from the number of pigs in them and the time they spend in there.

The grower sheds hold 880 pigs for 20 weeks. Therefore the throughput capacity is: 44 per week (880 ÷ 20 = 44).  Adjust this figure to cover post-weaning deaths and give a target for the number of piglets to be transferred to the weaner shed each month.

Assume about 5% of pigs die post-weaning. To reach the throughput capacity of 44 per week, the herd target is to produce 46 weaners per week (44 x 105 ÷ 100 = 46).

This target number of pigs for transfer each month to the weaner shed is one of the most important production targets for the piggery.

Next decide on the number of pigs in each type of pen and the time spent there. Factors such as the health status of the herd, temperature and ventilation control, pen design and the need to minimise re-mixing of pigs will influence the number of pigs per pen you finally decide on.

Animal welfare codes

Remember you are obliged to observe the welfare code requirements on stocking rates (also given in Table 1). The Model Code of Practice for the Welfare of Animals - Pigs 3rd edition, provides a guide to minimum space allocations and provides more detail than is given here.

Table 1. Minimum area requirements for all floor surfaces except deep litter
Description Space (m²/pig)*
Growing pigs about 10 kg 0.14
averaging 20 kg 0.22
40 kg 0.36
60 kg 0.47
80 kg 0.57
100 kg 0.66

Step 2: Set breeding herd targets

Once the throughput schedule for your grower shed is established, you can work out targets for the breeding herd. The process is: Determine the target number of litters per week based on the target number of weaners and the average litter size weaned.

If 46 weaners are required per week, and the average litter size at weaning is 9.2, then five litters are needed each week (46 ÷ 9.2 = 5). Determine the mating target based on the target number of litters per week and the average farrowing rate of the herd. The weekly mating target may need to be varied if predictable fluctuations in seasonal fertility occur in your piggery.

With a farrowing rate of 83% and a farrowing target of five litters a week, the mating target is six matings per week (5 x 100 ÷ 83 = 6). Ensure that gilt selections or purchases are planned well enough in advance to meet the mating targets. This is the ultimate objective of the production plan.

There is usually a one- to two-month delay between selecting gilts and mating them. Therefore, check the expected number of weaned sows available for re-mating, at least two months in advance, when planning your gilt selections. Allow for at least 10% wastage of gilts by selecting spares. As a guide, for every 100 sows, at least eight gilts are required in the gilt pool at any one time. Many farms cannot meet their mating target because they fail to keep or buy enough gilts.

Step 3: Balance the breeding and grower herd production

The plan developed so far may not fit the total space resources of the piggery. Adjustments may be needed to compensate for the breeding and growing facilities not being in balance. The production plan will identify bottlenecks in the system and provide a basis on which to consider alternative options.

There are three common situations where the production plan needs finetuning to fix an imbalance between breeding capacity and grower space.

Situation 1. Short of farrowing pens compared with growing space

The example plan requires five litters per week to keep the grower sheds full. The piggery needs 25 farrowing pens to manage that number of farrowings, assuming weaning at four weeks plus one week clean up and waiting time between litters (5 x 5 = 25). What are the options if the shed has fewer farrowing pens than this?

There are three ways to compensate for a farrowing pen shortage:

  • Increase the number of litters farrowed per pen each year. This could be done by shortening the clean-out time between sows and/or by reducing weaning age. In many cases, these options won't be suitable. If weaning age is younger, you'll be more dependant on the quality of weaner food and housing.
  • Improve litter size weaned, thus cutting down the farrowings needed to get the target number of weaners. You may be able to do this by increasing the number born/litter (e.g. through timing of mating) or reducing piglet mortality, if these two parameters are below-average industry performance. You may also be able to foster all the piglets from one sow to other sows, and wean this sow very early, possibly for culling.
  • Slightly increase the target selling weight, for boars in particular. By increasing the selling weight, the throughput capacity and the number of weaners required per week is reduced. Depending on your market requirements, be careful not to raise selling weights too high as a large drop in backfat grades may reduce overall profit.

If these methods do not rectify the shortage of farrowing pens, evaluate the economics of installing more pens to balance up the piggery.

Situation 2. Surplus farrowing pens compared with growing space

In this situation, increasing sow numbers to fill the farrowing pens and marketing at lighter weights won't generally be profitable.

If the original target weight was right, more farrowings will force selling weight below that which is most profitable. The exception is when there is little difference in profit over a range of selling weights, which may be the case for gilts. In this case, the extra throughput may more than compensate for the reduction in selling weight.

There is generally more scope to reduce the sale weight of gilts to lift throughput and profit, because they may be fatter at a given weight than boars.

Surplus farrowing pens can be used to advantage by keeping piglets in them for longer.

If there is a large surplus of farrowing pens, evaluate the economics of adding more growing space to match the farrowing capacity.

Situation 3. Shortage of sow and gilt accommodation

The example plan requires five farrowings per week. If 2.2 litters are farrowed per sow per year, the piggery needs 118 sows plus a supply of unmated gilts (5 x 52 ÷ 2.2 = 118). A shortage of dry-sow housing is a good incentive to improve the number of litters per sow per year. If litters per sow a year could be increased to 2.3, five fewer sow places are needed.

If sow accommodation is still short, reduce the throughput target for the grower shed and use some grower space for sows, or consider building more sow and gilt pens.

Ongoing review

Once the plan is acceptable, it will need continual review and updating, particularly in the early stages. Actual production must be checked against the targets.

Changes in herd efficiency will require alterations to the production plan. For example, improvements in litter size weaned mean that fewer farrowings are needed per week to get the target number of weaners per week. If litter size weaned improves, you should try and improve growth rate to capitalise on extra throughput.

If the farrowing rate worsens, more matings are needed to meet the farrowing target. This may occur in summer.

Faster growth rates mean extra throughput capacity in the grower shed, and extra weaners are then needed each week to keep the sheds full.

Preparing the plan

Draw up the production plan with an adviser or private consultant. You can be too close to the project to appreciate the full range of options. Consultants and advisers have the experience of doing similar plans for other people and can do your job more quickly. Software such as AUSPIG can assist in preparing a plan aimed at profitable production.

If you are planning piggery extensions, the expansion design must be done with the overall production plan firmly in view.