Pig and Goat Feed Cost Calculator NZ
This works out what it costs to feed a pig or a goat through to a target weight, what that comes to per kilogram of gain, and what the meat costs per kilogram of carcass once dressing out is counted. That last figure is the one to use, because a cost worked out per kilogram of liveweight and then compared against a shop price per kilogram of meat is comparing two different things, and it flatters the home grown animal every time by whatever the dressing out percentage happens to be. On a pig that is a large share and on a goat larger still, so the error is not small. The other thing worth including is the weaner. It has to be bought or bred before anything is fed to it, and leaving it out is the most common way a back of the envelope calculation comes out cheaper than it should. No feed intake, growth rate or dressing out percentage is supplied here. All of them differ by breed, by the ration and by how the animal is kept, and a pig on cheap or waste feed is a completely different proposition from one fed on bagged meal. Whether it works out cheaper than buying is a real question, and it is often not the reason people do it anyway.
The same total divided by liveweight would read $6.01 rather than $8.35, which is the difference the dressing out percentage makes. Divide by carcass weight, not liveweight. Comparing a cost per kilogram of liveweight against a shop price per kilogram of meat always flatters the home grown animal.
How it works
The gain needed is the target less the starting weight, and dividing by the daily gain gives the days it will take. Feed is the daily amount multiplied by those days and by the price. Cost per kilogram of gain divides the feed bill by the weight put on, which is the figure for comparing rations. The carcass weight applies the dressing out percentage to the target liveweight, and the cost a kilogram of carcass divides the whole bill, including the weaner and the processing, by that carcass weight.
Where a quick estimate goes wrong
Three places, all of them in the same direction. Leaving out the weaner, which was paid for before any feed was bought. Dividing by liveweight rather than carcass weight, which understates the cost of the meat by the dressing out percentage. And leaving out processing, which on a single animal is a substantial fixed cost spread over not very many kilograms. Any one of them makes home grown look cheaper than it is, and together they can easily halve the apparent cost.
Worked example
A weaner bought at 20 kilograms and grown to 95 has 75 kilograms to put on, and at 0.65 kilograms a day that takes 115 days. Eating 2.2 kilograms of feed a day at 95 cents that is $241.15 of feed, which works out at $3.22 a kilogram of gain. At 72 percent dressing out the carcass is 68.4 kilograms. Adding the $150 weaner and $180 of processing brings the total to $571.15, which is $8.35 a kilogram of carcass. Dividing the same total by the 95 kilogram liveweight instead would have given $6.01, which is the number that makes home grown look cheap and is not what the meat cost.
Related calculators
- Pig Gestation: breeding your own rather than buying in.
- Feed Conversion Ratio: the same question for cattle and sheep.
- Egg Production Flock Size: the poultry version.
- Goat Gestation: kidding due dates.