The introduction of the new pig grading system has significantly changed how farmers approach sale weight.
For many producers, the practical target has moved towards approximately 118-120 kg live weight, with the aim of maximising the proportion of pigs falling within the Golden Box for both weight (80 to 94.99kg dead weight) and lean meat (>60%).
Achieving the Golden Box is clearly important, but the question for farmers is whether it should be the only consideration when deciding when to sell pigs.
The new grading system means that weight and lean meat percentage need to be considered together.
Genetics
Where pigs are consistently falling outside the Golden Box, there is an opportunity to improve returns through changes to genetics, nutrition, health or management.
Bringing sale weight back towards 118-120 kg has been an appropriate response on many farms, but achieving the desired grading result does not automatically mean that this is the most profitable sale point for every farm. The important question is: what happens to the cost of production when pigs are sold lighter?
Slaughter data
Analysis of slaughter data from several farms provides an interesting perspective. In some cases, reducing sale weight has resulted in an increased percentage of pigs getting into the Golden Box. However, as the average sale weight falls, the non-feed costs per pig remain the same, therefore the non-feed cost per kg dwt increases. Where is your sale weight sweet spot, whereby you maximise the net pig price while minimising the non-feed cost per kg?
Space and stocking density are also important. Reducing sale weight allows pigs to leave the farm sooner and may help relieve stocking pressure.
The challenge is therefore to find the economic optimum for each individual farm
On a farm operating close to capacity, getting pigs away earlier can have a significant benefit by improving throughput and reducing pressure on accommodation. Where space is not limiting however, the economics of carrying pigs for additional kilograms may be very different.
Equally, simply keeping pigs to heavier weights is not necessarily the answer. Once pigs move beyond their optimum point, feed conversion can deteriorate and the cost of producing each additional kilogram can increase. If heavier pigs move outside the most favourable area of the grading grid, the additional carcase weight may not generate sufficient income to compensate for poorer grading and the cost of keeping the pig for longer. The challenge is therefore to find the economic optimum for each individual farm.
Farmers should use their own data to assess sale weight alongside:
What is optimal on one farm may not be optimal on another. A farm with high non-feed costs and limited space may place greater value on reducing days on farm, while a farm with lower costs and sufficient accommodation may benefit from carrying pigs for additional kilograms.
The Golden Box remains a critical target, but it should be viewed as part of the decision rather than the entire decision. Farmers need to know not only how many pigs are achieving the target, but also what it costs to get them there.
The more useful question is therefore not simply, “What weight should I sell my pigs at?”, but “At what weight does selling another kilogram give me the best return on my farm?”. AI apps can help to rapidly estimate the optimum weight, but it is important to include your monthly non-feed cost and monthly pig sales in this calculation. A more detailed analysis (see Table 1) can be obtained from your Teagasc specialist pig adviser.
