Resource centerGrowth & weights4 min read
ADG: average daily gain
Grams per day is the fastest way to see whether feeding and genetics are working.
The question
A lamb weighed 18.5 kg at 50 days and 32.8 kg at 100 days. Is that good? On its own, the number means little; divided by the days, it becomes comparable.
The concept
Average daily gain (ADG) is the weight gained between two weighings divided by the days between them: (32.8 − 18.5) ÷ 50 = 0.286 kg/day, or 286 g/day. It is a phenotype: what actually happened to this animal in this period, feed and weather included.
Why it matters
ADG tells you when a lot is falling behind before the sale date arrives, which lambs will reach target weight first, and whether a change of ration paid off. It is also the raw material for the "days to target" forecast in market objectives.
The data behind it
BreedIQ computes ADG from recorded weights only and shows which animals qualify and which are excluded. The Dashboard displays the actual ADG of the flock for three stages: birth → 50 days (244 g/d over 71 animals in the demo), birth → 100 days (244 g/d, 57 animals) and birth → 6 months (242 g/d, 35 animals). The Growth analysis page (Productivity › Growth) breaks each stage down by breed, sex, lot and birth year and plots the evolution by birth month, omitting months with no animals rather than drawing a zero.
- 1Status of the last EBV calculation (expand to see warnings)
- 2Needs attention: alerts and open tasks for the whole flock
- 3Genetic evaluation: date of the last run and number of traits
- 4Active animals in inventory
- 5Prolificacy: lambs born ÷ lambing events
- 6Actual average daily gain (ADG) by stage: birth→50 d, →100 d, →6 months
- 7Inventory: active, sold, slaughtered, dead, other exits
- 8Category cards: ewes, ewe lambs, sires, ram lambs, males to review, culling
- 9Filters: breed, lot and period
How to read it in BreedIQ
In the animal profile, the Overview card shows "ADG to weaning: 310 g/d" and "ADG (birth→latest): 310 g/d". The Weights tab shows the ADG since the previous weighing for each row, and the Performance tab adds the group's comparable average and the difference ("+2.14 kg (+13.1%) within range"). In Carcass & Market, "ADG since last weight" drives the days-to-target column.
A worked example
A lamb at 30 kg with a target of 40 kg and a recent ADG of 250 g/day needs about 10 ÷ 0.25 = 40 days. BreedIQ shows this as "days to target" and a forecast date, and warns when the forecast rests on an old weight ("This forecast rests on a weight taken 96 days ago. Weigh again to sharpen it").
Decisions it supports
Schedule the next weighing, move slow lambs to a different ration or group, decide the sale date of a lot, and spot a health problem early when a whole group's ADG drops.
Limitations
ADG is not a breeding value: a lamb that gained fast because it was a single on the best pasture will not necessarily transmit that. Use ADG to manage; use Growth to select. Two weighings close together exaggerate scale error, so BreedIQ shows the days covered next to the figure.