Tapioca in piglet feed a useful source of energy

Tapioca is a good source of energy for piglets due to its high starch content. In regions where it is produced it is a useful alternative to imported grains.

Tapioca is produced from cassava roots grown in South America, Africa and Asia.
Tapioca is produced from cassava roots grown in South America, Africa and Asia.

Tapioca is a high-starch product extracted from cassava roots (Manihot esculenta). Cassava is native to Brazil but is grown throughout South America, as well as Africa and Asia. Tapioca products are produced in both manual and mechanized production systems. The following steps are necessary to produce tapioca flour, with a starch content of 94 percent, which is used in human food production.

  • Peel and wash the roots
  • Chop and grind the roots
  • Mix with water to form a slurry
  • Filter slurry to separate starch from fiber (fiber levels may be further reduced by centrifuge in industrial systems
  • Dry, using hot air or the sun
  • Sift the powder and pack into bags

Tapioca chips, pellets and meal are more commonly used in pig diets and have higher fiber levels. Following peeling and washing, the roots are chipped and dried before packaging. The dried chips are ground to produce a meal that can be pelleted.

Trade

More than half of cassava grown worldwide is used for human consumption; the rest is used for industrial purposes and for animal feed. Nigeria is the biggest producer of tapioca, followed by Brazil, but neither are significant exporters. It is the third largest producer, Thailand, that is the largest exporter of tapioca, having invested in industrial production facilities. China is the biggest importer of tapioca.

Tapioca has been historically used in Europe, particularly the Netherlands and Spain. However, certainly in the Netherlands, it hasn’t been commonly used in the last ten years, as prices have not been favorable compared to cereals. In Spain, some pig producers use tapioca, but in most cases, more consistent products are favored.

Import levies and quotas also affect the cost of using tapioca outside producing countries. At time of press, the price of tapioca chips was $230-240 per MT (FOB Bangkok). In south-east Asia, tapioca is a common and economical ingredient in piglet diets. Producing countries in Africa and South America commonly feed cassava to backyard pigs. Most often these are parts of the root that have been discarded following the production of tapioca flour; dried cassava peels, for example.

Nutritional value

Tapioca is lower in fat and protein, including sulfur amino acids, than cereals. Therefore, higher levels of protein ingredients may need to be included compared to diets based on cereals. Cassava contains small granule starch with a low amylose content, making it highly digestible and particularly suitable for feeding to piglets. It has also been shown to be preferentially palatable in free choice experiments.

Application

In Thailand, the two main constituents of pig diets are tapioca and broken rice, with corn reserved for pre-slaughter rations. Similarly in the Philippines and Vietnam, tapioca is included when available. In these countries, inclusion levels for young piglets (5-10kg) are 10-15 percent, going up to 25 percent for animals weighing 10-25kg. In older pigs, inclusion rates can reach 40 percent of the diet. If tapioca is added to mash diets, the dustiness can cause respiratory problems, so maximum inclusion levels are significantly reduced. Benefits to heat-stressed animals are attributed to the digestibility of tapioca. Some nutritionists have tried to exploit a potential prebiotic effect, whereby the pH of the large intestine is reduced by the fermentation of the starch. In Spain, the recommendation is that after 5 weeks of age tapioca can be added to piglet diets at 3 percent; however, in the Netherlands levels of 10-15 percent were commonplace.

In trials with weaning pigs, levels of 20 to 30 percent tapioca have been fed, with performance being the same or better than with corn-soya controls. Nursery pig trials in the U.S. also demonstrated that tapioca could successfully replace corn. Trials in India replaced up to 50 percent corn in the diets of 12 week old pigs. Improvements in average daily gain (ADG) were seen, with no differences in FCR or feed intake. Superior digestibilities were also seen, along with a reduction in diet cost, based on local economics. Experiments have shown digestible energy values for pigs of between 14.5 and 16.5 MJ ME per kg DM, depending on the starch and fiber levels of the ingredient used. These metabolizable energy levels are comparable to corn.

Quality control

The variability in quality can be an issue for tapioca products and control procedures must be in place. It is important to ascertain the starch level, before including tapioca in any formulation. The color of the product gives an initial indication of its quality; pellets or granules that appear burnt will have reduced nutritional value. However, sufficient drying is required to prevent mold growth and potential mycotoxin contamination.

Other common contamination is from soil, if the roots are not washed sufficiently. A high level of silica in tapioca not only causes problems in the mill due to abrasion but also affects the palatability of the product and can cause gastric ulcers. Preparation methods and drying also affect the amount of bitter compounds in tapioca products, the presence of which can reduce feed intake.

Fresh cassava roots contain relatively high levels of cyanogenic glycosides. This is a greater issue with cultivars grown in Asia than those found in South America. As with other parameters, efficient drying is key to reducing cyanide levels. Pelleting also reduces levels in the tapioca before it is included in feed. The following criteria need to be maintained to ensure that tapioca is suitable for use in piglet diets:

  • Starch >62.5 percent
  • Moisture <13 percent
  • Molds <45,000 ufc/g
  • Aflatoxin B1 <50ppb
  • Insoluble ash <4.5 percent
  • Cyanide <100ppm

Future prospects

Tapioca can be a useful source of energy for piglets, offering highly digestible starch. However, low protein levels, price and quality issues affect its use in importing countries. In countries where cassava is grown, it is a practical option for pig diets. It also reduces the need to use imported grains, particularly where there is competition for their use in human food. Whilst many studies have been carried out in growing and finishing pigs, trial data with piglets is limited.

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