Chickens feedingPoultry producers have been using commercial feed enzymes since the late 1980s to improve the digestibility of feed. Phytases were the first enzymes to gain commercial acceptance, and carbohydrases were introduced soon after. As described in a previous blog post, when added to feed, phytase maximizes the available phosphorous essential for cell growth and repair, while carbohydrases increase the digestibility of starches and sugars, both key sources of energy in the diet.

In the past few years, however, a significant rise in the cost of protein feed ingredients have expanded this focus to include enzymes that can further break down animal and vegetable proteins in the feed, thus reducing the amount of protein required. As a result, proteases are an emerging class of enzyme feed additives that are gaining interest and traction in the market.

Typically, broilers are only able to digest 80 to 90 percent of amino acids in feed. The rest make their way to the hindgut, where they serve as fodder for opportunistic pathogens that proliferate and cause inflammation, which in turn compromises the lining of the small intestine. Affected animals often have to be culled, and even those that recover lose a significant amount of weight in the effort to get well.

Since the introduction of protease feed additives in the market is fairly recent and customers have various commercial protease products from which to choose, we offer these five factors for poultry producers to consider when deciding which product will work best for their operations:


1. Is it a broad-spectrum protease?

The ideal enzyme additive breaks down a broad range of vegetable- and animal-based proteins, whether they’re soluble, insoluble, highly digestible like soybean meal, or hard to digest like feather meal. BRI’s protease feed additive, Versazyme, has been tested on a variety of vegetable and animal protein sources, including complex ones like keratin and elastin, and has been shown to degrade proteins better than other proteases tested.

2. Will it work optimally in the small intestine?

Nutrient absorption takes place in the small intestine, where pH levels range from neutral to alkaline. In chemistry, pH is a measure of a solution’s acidity or basicity. Solutions with a pH less than 7 are acidic while those above 7 are alkaline. The pH level where the enzyme is most active is known as its optimum pH. An acidic protease will be most active in the stomach, while an alkaline protease will work best in the small intestine. BRI’s alkaline protease has an optimal pH of approximately 7.5.

3. Is it stable throughout the feed production process and in the animal’s gut?

All enzymes are complex biological structures. An enzyme’s activity could be reduced or destroyed if its structure is altered, for example, by the high temperature conditions required for making pelleted feed, or by acidic pH conditions in the animal’s gut. An ideal protease, therefore, should not be easily destroyed or altered by changes in temperature or pH. BRI’s protease has demonstrated stability in the pelleting process for up to 90°C. A protease feed additive must also be able to withstand acidic conditions without losing its effectiveness as it makes its way from the stomach to the small intestine. BRI’s protease shows pH stability both in the laboratory and in animal trials.

4. Does it work best in temperatures that match the temperature of poultry?

It is important for an enzyme to work optimally in temperatures that match the physiological temperature of most animals, including poultry. BRI’s enzyme was discovered by BRI’s founder, Dr. Jason Shih, in a thermophilic (heat-loving) poultry waste digester, so it can withstand high temperatures. It works best in temperatures of 35-55°C (95-131°F). The average body temperature of a chicken is 42°C (107°F).

5. Will it work well in a poultry farm environment?

Certain enzymes may work well in the laboratory but lose some of their effectiveness when deployed in the farm where most environmental factors cannot be controlled. BRI’s feed enzyme was discovered and isolated in bacteria living in poultry waste. Thus, it is naturally well-adapted to living in the guts of chickens and around poultry farms. Not surprisingly, its effectiveness has been demonstrated not just in laboratory tests but in many commercial farm trials worldwide.


In summary, the chances that a protease feed enzyme will successfully make the transition from the laboratory to commercial poultry production are increased if it is a robust, heat-stable, broad-spectrum protease that works optimally in an animal’s digestive system and is compatible with the poultry farm environment.

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