“I’m confident that if the experiment were repeated today, nearly any pig raised on raw scraps and aquatic plants from polluted ponds or lakes would end up with intestines suitable for use as pipe filters.”
Nguyễn Đình Tường – Director of Đồng Tâm Livestock and Services Cooperative. Photo credit: Dương Đình Tường
A Surprising Discovery in Pig Farming
“Some pigs had thicker intestines, others thinner, but all developed what we call ‘pipe-filter intestines’. However, raising pigs this way is extremely risky,” said Mr. Nguyễn Đình Tường, Director of Đồng Tâm Livestock and Services Cooperative (Cấn Hữu Commune, Quốc Oai District, Hanoi).
Back in 2000, Mr. Tường started raising pigs in a residential area using basic cement pens and troughs. His first batch included 40 pigs, and subsequent batches grew to 80. Once he exceeded 40 pigs, he stopped cooking their feed and switched to a raw diet. Conveniently, there was a pond near the pigsty—owned by his brother—filled with duckweed and water hyacinth. Each day, he and his wife would scoop plants from the pond to feed the pigs.
When the pond ran out of vegetation, they pushed a modified ox cart around the village’s canals to collect more water hyacinth and wild morning glory. These were chopped and either mixed with raw bran or fed directly to the pigs to reduce costs.
“When we slaughtered that batch of 80 pigs, most had intestines resembling pipe filters. Some pigs had full sets, others about two-thirds. Although I dewormed them regularly, it wasn’t enough. The raw plants from polluted ponds were full of parasite eggs. These pigs grew slowly, had coarse hair, and instead of reaching 80–90 kg in 4–5 months, they only hit 60–70 kg.”
“When butchers opened the intestines, they were packed with roundworms and tapeworms, visibly writhing—pretty horrifying. Once sliced, the intestines shrank and firmed up—holding them felt like grabbing a finger. The more parasites, the thicker the intestines became, matching the so-called ‘pipe-filter’ type. A mature pig’s small intestine is usually only 7–10 meters long—not 40 meters like some online ads claim.”
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“At the time, I thought raising pigs that way to produce ‘pipe-filter intestines’ was an interesting idea,” Mr. Tường recalled. “So, for the next batch, I conducted an experiment with half the herd—40 pigs—feeding them raw vegetables collected from ponds, lakes, and irrigation ditches, chopped and mixed with uncooked bran. All of them developed ‘pipe-filter intestines’, but there were two things I didn’t like.
First, the pigs grew slowly. Second, the price difference between ‘pipe-filter intestines’ and regular intestines was only about 20–30%, since I wasn’t slaughtering the pigs myself but selling them to butchers. Back then, not many people appreciated the difference. It wasn’t until a few years later that they started gaining popularity.”
“I realized that while this method produced intestines that sold for a slightly higher price, I didn’t benefit from it—only the negative effects stayed with me. The pigs’ growth was stunted because parasites consumed much of the nutrients. And once a pig is infected with tapeworms in its intestines, chances are the parasites are also in the lungs and even the bloodstream, making the meat unsafe for consumption. That’s why I ultimately chose not to continue raising pigs that way,” Mr. Tường explained.
Safe Pig Farming Means No More “Pipe-Filter” Intestines
In 2008, Mr. Tường relocated his pig pens outside the residential area and shifted to an industrial-style farming model, increasing the herd size to 200 pigs per batch.
In early 2014, his farm was selected as one of 37 across the entire city to participate in a project organized by the Hanoi Department of Agriculture and Rural Development. The project promoted pig farming using biological (organic) feed. The results were impressive: improved environmental cleanliness, better disease prevention, and most notably, pork that was fragrant, firm, sweet, and flavorful—distinctly superior to pork raised on conventional industrial feed and significantly safer than pork from traditional, raw-vegetable-based farming methods.
After more than 10 years of raising thousands of pigs using biosecure methods, not a single one has had ‘pipe-filter intestines’. Photo: Provided by the subject.
By late 2014, when the project ended, only Mr. Tường and Mr. Nguyễn Trọng Long – Director of Hoàng Long Cooperative in Thanh Oai District – remained committed. Mr. Tường continued importing pig breeds and biological feed to raise pigs using the biosecure method. At the same time, he actively sought out markets and promoted his biologically-raised pork products.
In 2016, realizing that continuing alone on this new path would be slow, he gathered other local farm owners to establish the Đồng Tâm Livestock and Services Cooperative. Around that time, the Hanoi Department of Agriculture and Rural Development launched another project supporting biosecure livestock models. Just like with the first project, Mr. Tường enthusiastically joined and remained involved until its completion in 2020.
In parallel with raising pigs, Mr. Tường had already begun on-site livestock slaughtering in 2006, processing an average of 500–700 pigs annually.
Since 2014, I’ve been raising pigs under a biosecure model—not industrial, not traditional. After slaughtering thousands of pigs, I haven’t seen a single one with ‘pipe-filter intestines.
Some pigs might have a thicker, crunchier segment at the beginning of the small intestine—where it connects to the large intestine—but that’s nothing like ‘pipe-filter intestines’. The longest ones are about 70–80 cm, and some as short as 20–30 cm.
Back in the day, when we fed pigs raw bran and duckweed, I wouldn’t dare touch, dream about, or even think about ‘pipe-filter intestines’—they were horrifying. I still remember slicing open intestines and cutting through a tapeworm inside. Some of them looked like miniature stingrays, with their wings twitching in the bowl like fish swimming.
I once flipped one over, poked its mouth with the tip of my knife, and heard it make a faint clicking sound. These parasites have such strong jaws that they bite deeply into the intestinal wall and rarely come off, even with deworming. Other parasites, when drugged, lose grip and are flushed out—but this one, even when affected by medicine, stays latched on and just hangs there in the gut. I can’t even imagine what would happen if such a parasite entered a human body.
Now, pigs are fed processed feed and drink clean water—so even if ‘pipe-filter intestines’ are fetching several million đồng per kilogram on the market, we simply don’t have them,”** Mr. Tường confirmed.
Source: nongnghiep.vn