Optimal feed particle size for animals, poultry, livestock and fish

In intensive farming practices, precise control of feed particle size has become a key technical parameter for improving farming efficiency. Based on the principles of animal nutrition and physiological characteristics of the digestive tract, this paper systematically analyzes the differentiated needs of poultry, ruminants and aquatic species for feed particle size. Combining international feed production standards (ISO/TC34/SC10) with localized production data, this paper discusses the key points of feed pellet machine in particle size control, and provides practical particle size optimization solutions for farming practitioners.

Why is feed particle size so important?

In modern farming, feed particle size directly affects animal feeding efficiency, digestion and absorption rate, and growth performance. Appropriate particle size can reduce feed waste (up to 15%), and precise control of feed pellet machine is the key equipment to achieve this goal. Imported particle standards are usually based on years of scientific research data. For example, the EU FEFAC standard has strict regulations on the matching degree of particle hardness, diameter and animal oral structure, which is why domestic farms often choose imported formulas.

Golden size of poultry feed

Chicks (0-3 weeks)

1.5-2mm diameter crushed pellets for easy pecking

Growing chickens/laying hens

3-3.5mm cylindrical pellets, which need to be compressed to 1:8 by feed pellet machine

Meat ducks/breeding ducks

4-5mm short rod-shaped pellets, the length does not exceed 1.5 times the diameter

Studies have shown that when the particle size error exceeds 0.3mm, the feeds intake of broilers will decrease by 7% (P<0.05).

Special needs of ruminants

Calves (before weaning)

6-8mm puffed pellets, which need to contain 15% crude fiber

Fattening cattle

8-12mm high-density pellets, combined with the secondary pelleting process of feeds pellet machine

Goats/sheep

4-6mm irregular pellets, the surface roughness should be >50μm to promote rumination
The US NRC standard points out that when the particle length exceeds 1.2 times the diameter of the animal’s esophagus, the rumination time will be extended by 23%.

The code of particle size of aquatic feed

Special requirements for particle diameter of fish species Catfish fry 1.2-1.8mm need to add 5% adhesive to prevent loss Adult rainbow trout 3-4.5mm floating particles, density 0.8g/cm³ Carp 2-3mm slow sinking type, sinking speed <5cm/s

Experimental data show that the feeds coefficient can be optimized by 0.3–0.5. This occurs when the particle size error of aquatic feeds produced by the feed pellet machine is controlled within ±0.15mm.

Transnational differences in particle size

Tests by German Big Dutchman company show that under the same formula, 2.8mm and 3.2mm particles make the daily weight gain of broilers differ by 11%. This explains why domestic high-end farms would rather bear a 25% tariff to import premixes that meet EU standards. They then use local feed pellet machines for final processing.