Reference Delivery
Rainbow trout raceway feeding upgrade — Italy
Illustrative scenario: Italian alpine trout farm replacing hand feeding across 32 raceways with pendulum demand feeders and a low-P extruded ration, targeting FCR and effluent phosphorus reduction to keep the discharge licence.
- Italy
- Country
- Aquaculture (rainbow trout)
- Category
- 800 t/year · 32 raceways · demand feeders
- Scale
- 3
- Reference outcomes
Load requirements
Design loads used to size housing, utilities and equipment.
Feed ladder
2 · 3 · 4.5 · 6 mm extruded, 42/22 protein/lipid
Daily feed peak
3.6 t/day
Water temp
10–15 °C spring-fed
Stocking density
35 kg/m³ (raceway)
Available P in feed
≤0.55% (low-P formulation)
Feeding pattern
Fish-triggered demand + 3 timed events
System design choices
Why each subsystem was specified the way it was.
| Area | Choice | Rationale |
|---|---|---|
| Delivery | 3 pendulum demand feeders per raceway + top-up hopper | Fish trigger dose only when hungry — matches spring-fed temperature swings without human guesswork. |
| Ration | Low-P, high-digestibility extruded pellets | Meets EU water-framework effluent P targets and improves faecal quality for downstream capture. |
| Waste capture | End-of-raceway settlement basin + drum filter | Recovers >70% of solid faecal load — protects licence and returns solids as agri-nutrient. |
| Sampling | Weekly biomass grading + growth curve reforecast | Cold-water growth swings weekly; ration table without reforecast overfeeds early and underfeeds late. |
| Oxygen | Cascade re-aeration + LOX injection on hot days | Summer inflow >14 °C strips DO — LOX safety-net keeps FCR intact through heatwaves. |
Results
Representative KPIs achieved on projects of this scope.
FCR
0.98
Harvest weight
380 g at 14 months
Survival
94.1%
Effluent P
−38% vs baseline
Labour on feeding
0.9 h/t harvested (was 3.4)
Representative outcomes
- Typical scope: 96 pendulum feeders, low-P ration
- Typical outcome: FCR 1.15 → 0.98
- Typical outcome: effluent P −38%
Note: This case study is an anonymized reference scenario. Specific client identities, contract values and commercial terms are withheld under NDA. Figures reflect typical outcomes for projects of this scope and are not a guarantee for your project.