animal feed machine

Yes, it matters — a lot. Think of compression ratio as the “hardness dial” on your feed. It determines how dense and durable the pellet comes out.

Here’s what we typically recommend, based on years of on-site commissioning across dozens of countries:
Poultry feed (broilers, layers): compression ratio around 1:9 to 1:13. Poultry don’t need rock-hard pellets — they peck and swallow. Too hard and they’ll waste feed.
Pig feed (starter, grower, finisher): 1:8 to 1:12 works well. Piglets need softer pellets, so we go lower — around 1:5 to 1:7 for creep feed.
Fish feed (carp, tilapia, catfish — sinking type): 1:14 to 1:16 is the sweet spot. Why so much higher? Because fish feed sits in water. It needs to hold together — 30 minutes minimum, ideally 2 hours.
Shrimp feed: 1:20 to 1:25. Shrimp are picky eaters — they hold pellets with their tiny claws and nibble. If the pellet crumbles too fast, it pollutes the water and you lose yield.

One more thing — don’t treat these numbers as gospel. The actual compression ratio also depends on your formula, moisture content, and steam conditioning. A high-fiber formula needs more compression; a high-oil formula needs less. Our rule of thumb: start with the recommended range, run a small batch, check pellet durability and water stability, then tweak from there.

Pelleting is a mechanical compression process: conditioned mash is forced through ring-die holes under high pressure, forming dense, compact pellets. This method is ideal for producing submerged feed for poultry, livestock, and bottom-feeding fish like catfish and shrimp. Pelleting requires less energy, has lower operating costs, and delivers higher throughput.

Extrusion, by contrast, is a high-temperature, high-pressure cooking process. Feed ingredients are subjected to mechanical shear and heat (120–170°C), expanding the product into a porous, lightweight structure. Extruded feeds offer superior digestibility (up to 90%+ starch gelatinization) and can be formulated as floating, slow-sinking, or sinking diets. This makes extrusion the go-to choice for high-value aquatic species (salmon, trout, shrimp) and premium pet foods.
Choose pelleting for cost-effective submerged feed production; choose extrusion when you need floating capability, maximum digestibility, or high-fat formulations.

Great question — and one we get almost weekly from clients in Eastern Europe, South America, and parts of Asia where forage is abundant. The short answer: you can run forage through a standard pellet mill, but you won’t like the results.

The challenge with fibrous materials

Straw and hay are light, fluffy, and fibrous. They don’t flow well and bridge easily in bins.
What a forage line needs that a standard grain line doesn’t:
1.Dedicated forage grinder — wider crushing chamber, forced feeding mechanism with a paddle wheel to pull the fluffy material in. Standard hammer mills choke on straw; forage mills are built for it.
2.Bale breaker (YPPK series) — if your material comes in compressed bales (round or square), you need to break them apart before grinding.
3.Forced-feed pellet mill — Forage won’t flow; it needs a forced feeder (a screw or paddle that actively pushes material into the die). Without this, the mill runs empty or surges — terrible for die life and pellet quality.
4.Higher torque, lower RPM motor — forage is harder to push through the die. We typically spec 6-pole or 8-pole motors (lower speed, higher torque) instead of the 4-pole motors used for grain.

And one more consideration: ring die material
For grain-based feed, we recommend stainless steel ring dies. For forage? Go with alloy steel — 42CrMo is our go-to. It’s more wear-resistant. Fiber is abrasive — it wears dies faster than grain.
The good news: once you have the right setup, forage pellets are fantastic. They’re easier to store, transport, and feed. And for ruminants like cattle and sheep, pelleted forage actually improves digestibility compared to loose hay.

A crumbler breaks large pellets into smaller particles. While not essential for all lines, it offers significant advantages for specific market segments.

Piglet feed is a primary application. Piglets cannot consume 4–5 mm pellets; by pressing larger pellets (faster and easier on the mill) and then crumbling to 1–2 mm, a yield of approximately 60–70% is achieved. Chick starter feed follows the same rationale — chicks peck and benefit from smaller particles.
However, for adult poultry or fish feed, a crumbler adds cost and complexity without benefit. It is recommended only when producing nursery pig, broiler starter, or shrimp feeds, where premium pricing justifies the investment.

Single-screw extruder: the workhorse
A single screw rotates inside a barrel, pushing material forward through friction and compression. Simple design. Lower cost. Easier to maintain. But it has limits:
Maximum oil in the formula before extrusion: about 8%.
Struggles with high-fiber or high-moisture formulas.
Output is sensitive to formula changes.
Requires more operator skill.Requires more operator skill.
Twin-screw extruder: the premium option
Two intermeshing screws rotating in the same direction. More expensive (typically 1-1.5x the cost of single-screw). But here’s what you get:
Handles up to 17%+ oil in the formula — no slipping, no issues.
Processes high-moisture ingredients (fresh meat, wet byproducts) without choking.
Better mixing and shear — more uniform gelatinization, better pellet quality.
Shorter warm-up time, faster recipe changes.
More forgiving — less operator skill required.

So which one should you choose? Here’s our rule of thumb:

· Choose single-screw if:
You’re producing mostly sinking fish feed (carp, catfish, tilapia) with starch ≥20%.
Your formula oil content stays below 8%.
Budget is tight.
You have experienced operators.
· Choose twin-screw if:
You’re making floating feed with high oil (shrimp, salmon, trout).
You’re making pet food — which often has 12-15% oil and varied ingredients (meat meals, grains, vegetables).
You need to switch formulas frequently.
You want consistent quality with less operator intervention.

The complete pet food line includes: storage and cleaning, grinding, batching, mixing, extrusion (twin-screw preferred), drying (multi-layer belt dryers), coating (flavour and fat application), cooling, screening, and packaging.

Key design features for pet food:
Shaping dies: Pet food requires visually appealing kibbles with consistent size, shape, and colour. Dies can be custom-engineered for specific shapes—round, triangular, heart-shaped, or bone-shaped—with hole sizes from 0.6 mm (for tiny bites) up to 16 mm (for large-breed kibble).
Drying systems: Multi-layer mesh-belt dryers with independent temperature zones prevent case-hardening (dry exterior, wet centre). Initial drying at 100–200°C for 4–6 minutes is followed by lower temperatures to avoid the Maillard reaction.
Coating systems: Palatability enhancers (fats, oils, digest, flavours) are applied post-extrusion using vacuum coaters (up to 36% oil absorption) or drum coaters (up to 12% oil). These systems precisely meter liquid additions to ensure every kibble receives uniform coverage without clumping.
Material selection: All food-contact surfaces are stainless steel to prevent corrosion and contamination.