The traditional measurement for the efficiency of a sow farm is ‘pigs per sow per year’. If you ask 100 pig farmers or pig farm managers how the farm is performing they will probably all quote how many pigs per sow per year they are doing. It is even used to compare the efficiency of different countries.

As a method of measuring sow farm efficiency it is seriously flawed. It tells us only what individual sows are doing but it tells us little about the business. The reasons are as follows.

Mathematically you are comparing two variables, pigs and sows!! For a good method of comparison you need to compare a variable against a fixed. For example to compare the fuel efficiency of cars we look at litres / 100km not how long it takes to use a tank of fuel!!

Farms cheat. For several reasons figures from farms are cheated. The most common reasons being because of a bonus scheme that pays for low mortality or high pigs per sow per year. The others are to hide theft of pigs and simply to make the figures for the farm look good. The most common method of cheating is having extra sows on the farm that do not exist within the recording system. Clearly this will increase ‘pigs per sow per year. I have also seen farms wean piglets and then put them back into the farrowing house to be weaned again next week (this was at a genetics company that paid bonus for pigs weaned – the company thankfully no longer exists!!).

And lastly what is a sow. This varies from country to country and within country. The variables are when a gilt becomes a sow. This can be at entry to the farm, at first mating, at being confirmed pregnant at about 5 weeks after mating or even at farrowing. The other variable can be when does a sow no longer exist as a sow, when it dies, or is sold, or is it once it is classified as a ‘cull sow’.

Clearly the number of sows used in the ‘pigs per sow per year calculation’ will have a massive effect.

What is the function of a sow farm?

Only one - to produce piglets. The priority is always to fill the nursery every cycle (be it daily or weekly). When I say fill I also mean that it will be full when it comes to time for sale – in other words if mortality from wean to finish is 5% then put an extra 5% of pigs into the system – so that sales are 100% of the capacity of the farm.

Once the number of pigs is achieved then the quality becomes more important. The bigger the weaned piglet the faster it will grow and the more saleable meat can be produced from the same nursery and finisher in the same time.

As a measure ‘pigs per sow per year’ does not tell us that target number of pigs are weaned. It therefore tells us nothing about the business.

Pigs weaned per week, as a percentage of a target is a much better measure of total sow farm efficiency.

Pigs per Crate.

As a method of comparing sow farm efficiency then measuring pigs weaned per farrowing crate is a much better way to compare farms. The number of farrowing crates (places) on a farm is fixed, so by comparing pigs weaned per crate it is possible to compare how good farms are at managing their limiting factor or bottle neck (how much space they have).

To measure pigs per crate divide total crates by 5 to give number of crates / week. Divide average number of pigs weaned per week by the number of crates per week.

Let us look at 2 identical 1,500 sow farms

Using conventional measurement of efficiency, both are similar, but Farm B is the best. When we look at pigs per crate Farm A becomes considerably better. As we are looking at a business and not just figures to feed our ego’s, translating this into sales shows a considerable financial difference.

(Lost sales assumes 5% mortality from wean to slaughter, 115kg slaughter weight and 23 UAH per kg).

So how can Farm B be better than Farm A (pigs per sow per year) but with a considerably lower income. Simple, both farms are good at managing their sows (as sows), but farm B did not manage the business (not enough sows and gilts and not enough sows bred) - SIMPLE!!

1. How to wean 11,5 pigs with lower producing sows?
2. What should be done in order not leave crates empty?
3. In what cases the piglets should be weaned earlier? 
4. Is increasing pigs per sow per year good for the business?
5. When should the sow feeds be controlled thoroughly?