How the numbers are worked out
Average daily gain (ADG) is the weight gained divided by the days between two weigh-ins. You get it two ways: overall, from the first weigh-in, and recent, from the weigh-in at least two weeks before the latest one. The projection uses the recent pace, because gain changes as an animal grows.
Projected fair weight is the latest weight plus recent ADG times the days left. The range runs between the overall and recent pace, and at least 10% either side. The gain needed is the pounds still to go to each end of the window, divided by the days left.
Pigs speed up after about 110 lb, so a lighter pig's projection rises to at least 1.8 lb a day from there. When the fair is more than about four months off (eight for steers), or far past what your log covers, you get a range from typical gains, or the date it would pass the maximum, instead of one long-range guess.
Example: a hog weighs 133 lb on April 26 and gained 24 lb in the two weeks before, 1.71 lb a day. Weigh-in is July 10, 75 days away, so 133 + 1.71 × 75 comes to about 262 lb. To finish between 230 and 280 lb it needs 1.29 to 1.96 lb a day.
Typical daily gains and fair weights
| Animal | Typical gain a day | Starting window here |
|---|---|---|
| Market hog | 1.5–1.7 lb under 110 lb, 1.8–2.2 lb finishing | 230–280 lb |
| Market lamb | 0.5–1.0 lb | 110–150 lb |
| Market goat | 0.25–0.5 lb | 60–120 lb |
| Market steer | 2.5–4 lb | 1,100–1,500 lb |
Gains are from university extension guides. The windows are only a starting point: every fair sets its own limits, so type in the ones from your fair book.
Questions 4-H and FFA families ask
How much should a show pig gain per day?
Most healthy pigs average 1.6 to 1.8 lb a day. WSU Extension puts growing pigs under about 110 lb at 1.5 to 1.7 lb, rising to 1.8 to 2.2 lb while finishing. Hot weather slows them down.
How do I figure out how much my animal needs to gain to make weight?
Take the weight you're aiming for, subtract today's weight, and divide by the days until weigh-in. A 150 lb hog with 60 days to reach 260 lb needs 110 ÷ 60, about 1.83 lb a day.
How do I calculate average daily gain?
Subtract the earlier weight from the later one and divide by the days between them. A pig that went from 100 to 155 lb in 30 days gained 55 ÷ 30, about 1.83 lb a day.
How much should a market steer gain per day?
WSU Extension says a healthy steer should average at least 2.5 lb a day over its last 100 to 140 days on feed, and many do better. 4-H steers range widely, from about 2 to 4.5 lb.
How much do market lambs and goats gain a day?
Lambs usually gain about 0.5 to 1 lb a day and goats about 0.25 to 0.5 lb. Goats grow slowly, so a goat that is light a month out has little room to catch up.
My animal is gaining too fast or too slow. What should I change?
Talk to your 4-H leader, ag teacher or extension agent before changing the ration, and follow the feed tag. If an animal stops gaining or loses weight, have your vet look at it.
How often should I weigh my animal?
Every two weeks is enough to see a trend. Weigh at the same time of day, ideally before feeding, so a full belly doesn't skew the number.
Sources: WSU, Monitoring your show pig's progress · WSU FS048E, market-ready 4-H beef · Mississippi State P2516, what weight show pig to buy · Ohio 4-H market lamb fact sheet · Montana State, Flathead 4-H nutrition slides · CSU Jefferson County, market goat project · Utah State 4-H livestock calculator. A planning aid only: your fair book, advisor and vet have the final word.