Executive Summary
South Africa’s animal feed industry produced approximately 5.95 million tons of compound feed in the first ten months of 2025, rebounding 4.1% from the 2024 contraction, according to AFMA (Animal Feed Manufacturers Association) data. Within this market, dairy cattle feed represents a high-value segment where pellet quality directly affects milk yield and farm profitability. This case study examines how a mid-sized dairy feed mill in KwaZulu-Natal, South Africa, addressed persistent pellet durability issues by replacing its aging horizontal cooler with a Hongyang SKLN series counterflow cooler, integrated with an SZLH(HYPM) series ring die pellet mill. The result was a Pellet Durability Index improvement from 89% to 97% and a fines reduction of over 60%.
1. Industry Context: South Africa’s Feed Market in Recovery
The South African animal feed market was valued at USD 2.46 billion in 2024 and is projected to reach USD 3.14 billion by 2033, growing at a CAGR of 2.74% according to IMARC Group. Dairy production is a significant driver: South Africa’s raw milk output reached approximately 3.73 million metric tons in 2024, with a forecast annual growth rate of around 2.0% through 2028 (USDA Foreign Agricultural Service).
AFMA’s October 2025 Animal Feed Report documented total monthly feed production of 632,068 tons, a 2.7% year-on-year increase over October 2024. Dr. Lucius Phaleng, trade adviser at AFMA, noted that “the m/m and y/y growth in feed production highlights the industry’s recovery” after the 2024 downturn. Dairy feed, in particular, has seen steady demand growth as commercial dairy farms expand herd sizes and seek nutritional consistency.
For feed manufacturers serving the dairy sector, pellet quality is not a marketing point — it is an operational necessity. Dairy cows are sensitive to feed form; studies published in the Journal of Dairy Science have demonstrated that pelleted concentrates improve feed intake consistency and reduce sorting behavior compared to mash feeds. Poor pellet durability leads to fines, which cattle often refuse, resulting in feed waste and uneven nutrient intake.
2. The Customer’s Challenge
The feed mill, located in the KwaZulu-Natal Midlands — one of South Africa’s primary dairy regions — produces approximately 8,000 metric tons of dairy cattle feed annually. The facility serves over 40 commercial dairy farms within a 150-kilometer radius. Its production line previously relied on a horizontal belt cooler installed in 2014.
By early 2025, the mill’s management identified three persistent problems:
Low Pellet Durability Index (PDI).** Routine quality checks showed PDI values averaging 89%, below the industry benchmark of 95% for dairy feed pellets. The low PDI was traced to uneven cooling: the horizontal cooler’s single-direction airflow created temperature differentials of up to 15 degrees Celsius across the pellet bed, causing thermal stress cracking in the outer pellet layer.
Excessive fines.** Fines generation at the bagging station exceeded 4% by weight, requiring additional screening and reprocessing. This added an estimated 2.3 labor hours per shift and increased energy consumption from recirculating reground material through the pellet mill.
Moisture inconsistency.** Final moisture content varied between 10.5% and 14.2%, exceeding the target specification of 12.0% ± 0.5%. In KwaZulu-Natal’s subtropical climate, moisture inconsistency also elevated mold risk during storage and transport.
The mill’s operations manager summarized the situation: “We were producing good pellets at the die — but we were losing quality after cooling. The numbers told us the cooler was the bottleneck.”
3. Technology Assessment and Equipment Selection
The mill evaluated three options: repairing the existing horizontal cooler, purchasing a used vertical counterflow cooler from a European supplier, or investing in new equipment. After a six-week assessment period, the team selected new counterflow cooling technology for the following reasons:
Thermal efficiency.** Counterflow coolers operate on the principle that cool ambient air enters at the bottom of the pellet column and moves upward against the downward flow of hot pellets. This creates a gradual, uniform temperature gradient. Research published by the American Society of Agricultural and Biological Engineers (ASABE) confirms that counterflow cooling reduces thermal shock cracking by maintaining a temperature differential of no more than 5 degrees Celsius across the pellet mass — compared to 15 to 20 degrees Celsius in horizontal systems.
Residence time control.** The counterflow design allows precise adjustment of pellet residence time via a variable-speed discharge mechanism. Dairy feed pellets, typically 4 to 6 millimeters in diameter with higher fat content from bypass protein ingredients, require longer cooling times than standard poultry feeds. The adjustable discharge rate enables operators to match cooling duration to pellet characteristics rather than accepting a fixed conveyor speed.
Energy consumption.** Because counterflow coolers use the natural buoyancy of warm air, they require lower fan power than horizontal coolers for the same throughput. The mill’s energy audit projected a reduction in cooler-related electricity consumption of approximately 18%.
The selected equipment was a Hongyang SKLN series counterflow cooler, paired with an existing series ring die pellet mill already operating in the production line. The SKLN series is designed for continuous operation in medium to large feed mills, with features including a pneumatic discharge system, an integrated cyclone for fines recovery, and a stainless steel mesh bed to prevent pellet deformation.
4. Implementation and Results
Installation was completed in July 2025 over a scheduled 72-hour maintenance window. The Hongyang technical team provided remote commissioning support, including airflow calibration, discharge rate programming, and operator training on moisture monitoring protocols.
The mill conducted a 30-day performance trial with the following quantified results:
| Performance Metric | Before (Horizontal Cooler) | After (SKLN Counterflow) | Improvement |
|---|---|---|---|
| — | — | — | — |
| Pellet Durability Index (PDI) | 89.2% | 97.1% | +7.9 percentage points |
| Fines at bagging station | 4.1% by weight | 1.5% by weight | -63.4% |
| Final moisture consistency | 10.5%–14.2% | 11.8%–12.3% | Within ±0.5% specification |
| Cooler energy consumption | 18.5 kW | 15.2 kW | -17.8% |
| Reprocessing labor hours per shift | 2.3 hours | 0.4 hours | -82.6% |
The PDI improvement from 89.2% to 97.1% placed the mill’s output above the 95% industry benchmark. More importantly, the consistency of results held across the full 30-day trial period, including during KwaZulu-Natal’s humid summer conditions when ambient temperatures regularly exceeded 30 degrees Celsius.
5. Customer Feedback and Service Experience
The mill’s operations manager reported three observations during the post-installation review:
First, the reduction in fines directly improved customer relationships. “Our dairy farmers noticed immediately. Less dust in the feed troughs meant less refusal, and they stopped calling about inconsistent loads.”
Second, the simplified maintenance of the SKLN cooler reduced downtime. The pneumatic discharge system has fewer moving components than the mechanical rack-and-pinion mechanism of the previous horizontal cooler, and the stainless steel bed surface is easier to clean between production batches.
Third, the Hongyang team’s responsiveness during commissioning was noted as a differentiating factor. When a minor calibration issue arose with the airflow sensor on the second day of operation, the technical team provided a revised parameter set within four hours via remote access, resolving the issue without requiring an on-site visit.
6. Conclusion
This case demonstrates that cooling technology — often treated as a secondary consideration in feed mill design — can be the decisive factor in pellet quality for dairy cattle feed. The combination of Hongyang’s ring die pellet mill and SKLN counterflow cooler enabled the KwaZulu-Natal mill to raise its PDI by nearly 8 percentage points, cut fines by over 60%, and achieve moisture consistency within a tight specification band. In a market where South Africa’s dairy sector is expanding at approximately 2% annually and feed producers are competing on quality rather than price alone, investments in post-pelleting equipment yield measurable returns in both operational efficiency and customer retention.
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Data sources: AFMA Animal Feed Report (October 2025); IMARC Group, “South Africa Animal Feed Market Size & Demand 2033″; USDA Foreign Agricultural Service, “South Africa Dairy and Products Annual”; ASABE Standard S319.4, “Method of Determining and Expressing Fineness of Feed Materials by Sieving.”*
Post time: May-29-2026
