Results feeding trials: mealworms for chicks

Early Mealworm Supplementation: Bigger Birds, Higher Floor Weight—at a Modest Feed-Efficiency Cost

We gave on-farm hatched chicks a 20 % live-mealworm boost for their first 10 days (2×16 pens, 20 Ross 308 chicks per pen). Results at day 35:

Metric	Mealworm	Control	Difference
Average BW	2 504 g	2 431 g	+73 g
Five lightest pens (mean)	2 413 g	2 366 g	+47 g
Feed intake (0-35 d)	3 418 g	3 281 g	+137 g
FCR 2500	1.392	1.363	+0.029
Weight CV	3.3 %	2.3 %	+1.0 pp

Take-aways

Heavier across the board – Average birds gained 73 g; even the lightest pens finished 47 g heavier.
Welfare & behaviour – Live prey stimulates natural foraging and activity.
Trade-off – A 3-point rise in FCR and a slightly wider weight spread accompany the growth boost.

These data show a clear growth advantage and a higher minimum weight for the mealworm group, balanced against slightly reduced feed efficiency, which is likely a result of increased chick foraging.

This research was supported by Vereniging Agrarisch Landschap Achterhoek

June 24, 2025