Stable Shrimp Feed Pelleting in Pakistan: How a Sindh Aquafeed Mill Built Reliable Capacity with the Hongyang SZLH420 Ring Die Pellet Mill

Pakistan’s aquaculture sector contributes roughly 0.4 percent of GDP and produces an estimated US$650 million of fish annually, while the government has set out plans to develop 100,000 hectares of aquaculture with an estimated investment of US$1.3 billion [1][2]. Shrimp farming, led by Pacific white shrimp (Litopenaeus vannamei), is the most commercially viable entry point, concentrated along the coastal districts of Sindh — Thatta, Sujawal and Badin [1]. Feed represents about 60 percent of direct operating costs in semi-intensive shrimp farming, yet until recently specialized shrimp feed was not produced locally and farmers depended on costly imports [3]. This case study describes how a mid-sized aquafeed mill in Sindh installed a Hongyang SZLH420 ring die pellet mill with steam conditioning to produce sinking shrimp pellets in-house. Over ten months of operation, the mill held stable throughput on fishmeal-soybean formulations, reduced fines and dust, and earned repeat orders from the vannamei growers it supplies. The project shows how a well-engineered pelleting system, matched to local raw materials and backed by responsive after-sales support, helps an emerging feed manufacturer compete in a fast-growing market.

Pakistan has a 1,001 km coastline, vast saline lands and growing domestic protein demand, yet its shrimp sector is still in the early stages of commercialization [1][4]. Commercial production is mainly traditional and semi-intensive, and a national policy brief notes that investment in hatcheries, feed production and farm management could raise output significantly by increasing the productivity of existing ponds [1]. The Punjab government has launched a Rs50 billion shrimp farming initiative that explicitly includes feed mills as part of integrated value-chain estates [5]. At the same time, a 2026 Planning Commission report, “Blue Economy under URAAN Pakistan,” identifies cluster-based aquaculture as a national priority, with shrimp farming as the entry point [2].

The feed gap is the industry’s most binding constraint. Historically, Pakistani fish farmers fed rice bran in mash form, and the concept of artificial manufactured feed is relatively new [6]. Raw-material volatility is a persistent problem: soybean meal is largely imported and subject to global market swings, while local ingredients vary in quality and mycotoxin contamination remains a concern [7]. For shrimp growers, imported feed raises costs sharply; local production of reliable, competitively priced sinking pellets is therefore widely seen as a prerequisite for scaling the sector [3].

The customer is a privately owned feed mill in Sindh, one of the first dedicated aquafeed producers in its district. It supplies sinking shrimp pellets to a network of small and medium vannamei farms across the coastal belt, where growers typically stock semi-intensive ponds and run two crops per year. Before the project, the mill purchased imported shrimp feed and resold it, a model that left little margin and no control over supply. Farmers complained about inconsistent pellet quality and high freight-driven prices; some returned to fish production after struggling with feed costs [3].

The mill decided to produce its own feed and began looking for a pelleting line suited to shrimp diets: fine grinding, thorough conditioning, a die geometry matched to small-diameter sinking pellets, and the durability to survive bagging, transport and pond application without crumbling.

After comparing equipment from several suppliers, the mill selected the SZLH420 ring die pellet mill supplied by Liyang Hongyang Feed Machinery Co., Ltd. The SZLH420 features a 110 kW main motor, a 420 mm ring die inner diameter, a 120 mm effective die width and a rated speed of 287 rpm [8]. For shrimp feed, Hongyang’s engineers matched the die with a low-compression ratio and small hole diameter suited to 1.5–2.5 mm sinking pellets, and paired the mill with a double-layer conditioner and steam supply.

Three engineering details mattered most for local conditions:

Hongyang also recommended maintenance practices suited to a mill with limited prior experience in pelleting, including die rotation schedules, proper cooling procedures and daily checks on steam quality.

Commissioning took nine days and included hands-on training for the mill’s operators on conditioning parameters, die and roller gap adjustment, and scheduled maintenance. Because the customer had no prior experience with ring die pelleting, Hongyang’s engineers placed special emphasis on the details that determine shrimp feed quality: consistent steam pressure, moisture control at the conditioner, and matching die thickness to the desired pellet durability.

Support continued after handover. In the first weeks, the mill reported slightly higher fines during start-up runs when the boiler was still stabilizing. Hongyang’s team reviewed the settings remotely, recommended adjustments to the steam line and conditioner configuration, and the issue was resolved within days.

“They did not disappear after the machine was installed. When our feed quality was not right, their engineers treated it as their problem.”

— Mill’s Production Manager

After ten months of operation, the mill reported the following outcomes:

• Stable throughput of 3.5 to 4.5 tons per hour on shrimp sinking pellets, with minimal variation across ingredient batches.
• Fines and dust at the cooler discharge reduced from an initial seven percent to below three percent, recovering saleable feed and reducing waste in transport and pond application.
• Pellet durability improved enough to survive bagging, road transport to coastal farms and hand broadcasting without excessive breakage.
• The mill’s grower network expanded as farmers recognized more consistent pellet quality and more competitive prices than imported feed; repeat orders now cover roughly two-thirds of the mill’s output.
• The mill added a second shift and began planning a larger line, encouraged by the stability of the SZLH420 under continuous operation.

“We started this project to control our costs and our quality. The Hongyang line gives us both. It runs steadily, the pellets hold together, and our farmers notice the difference.”

— Managing Director

Pakistan’s shrimp sector is at a turning point: government programs, private investment and growing export interest are all pushing toward expansion, but the sector will only scale if feed supply becomes reliable and affordable [1][2][5]. In a market where feed represents about 60 percent of operating costs, a pelleting line that holds stable capacity, minimizes fines and is backed by a supplier willing to support the customer after installation gives a feed mill the foundation it needs to serve farmers and grow [3].

For Liyang Hongyang Feed Machinery, the Sindh project reflects a consistent philosophy: sell equipment that works, stand behind it, and treat the customer’s production problem as the company’s own. In an industry where trust is rebuilt with every bag of feed, that approach is the most durable product of all.