Feed Enzymes




Feeding enzymes to poultry is one of the major nutritional advances in the last fifty years. It is the culmination of something that nutritionists realized for a long time but until 1980’s it remained beyond their reach. Indeed, the theory of feed enzymes is simple. Plants contain some compounds that either the animal cannot digest or which hinder its digestive system, often because the animal cannot produce the necessary enzyme to degrade them. Nutritionists can help the animal by identifying these indigestible compounds and feeding a suitable enzyme. These enzymes come from microorganisms that are carefully selected for the task and grown under controlled conditions (Wallis, 1996). The poultry industry readily accepts enzymes as a standard dietary component, especially in wheat and barley-based rations.

The increasing economic pressures currently being placed upon animal producers demand more-efficient utilization of low-grade feedstuffs. In addition, consumer awareness and new legislation require that any increase in animal production cannot be achieved via growth-promoting drugs or other chemical substances. One increasingly popular approach to this problem is to supplement animal diets with hydrolytic enzymes in an attempt to aid the digestion and absorption of poorly available nutrients, or to remove ant nutritional factors from the diet. Concerns raised by this practice include the ability of such enzymes to survive processing temperatures and even the animals’ digestive tract.

Enzymes are biodegradable and environmentally friendly
most manufacturing produces industrial waste that can present a threat to nature if it includes chemicals. Enzymes can usually do the same job cheaper and do not threaten the environment.


Enzymes are fully biodegradable. When industrial enzymes leave a production plant with the waste water, the retired enzymes do not last long in the surrounding environment. Nature has many microorganisms that easily break down enzymes into single amino acids, which are used to build up life around us.


The fact that enzymes create no hazardous waste makes them the most environmentally-friendly solution for industrial manufacturing.

All enzymes are proteins, but not all proteins are enzymes
Proteins are the building blocks of all living organisms. Humans, animals, plants and microorganisms are all made up of proteins.


Every part of the human body is built of proteins. Proteins constitute about 80% of the dry weight of muscle, 70% of the dry weight of skin and 90% of the dry weight of blood.


Animal feed is the largest cost item in livestock and poultry production, accounting for 60-70% of total expenses. To save on costs, many producers supplement feed with enzyme additives, which enable them to produce more meat per animal or to produce the same amount of meat cheaper and faster.

Found in all living cells, enzymes catalyze chemical processes that convert nutrients into energy and new tissue. They do this by binding to substrates in the feed and breaking them down into smaller compounds. Enzymes can be classified by the types of substrates they work on. For instance: proteases break down proteins into amino acids, carbohydrases split carbohydrates into simple sugars, and lipases take apart lipids into fatty acids and glycerol.

Commercially-available enzymes can be derived from plants and animals (e.g., actinidin from kiwi and rennet from calf stomachs) as well as microorganisms (e.g., amylase from Bacillus and lactase from Aspergillus). Aside from agriculture, other industries that utilize enzymes include the brewing, dairy, paper, biofuel, and rubber industries.

In this blog post, we will discuss three types of enzymes that are typically considered for use in poultry feeds: phytases, carbohydrases, and proteases.


  1. Phytases

Phytases break down phytate, a substrate that contains phosphorus. Phosphorus is a major nutrient that is essential for growth, maintenance, and cell and tissue repair. Corn, which is a major component of the typical poultry diet, contains significant amounts of phytate. Adding phytase to poultry feed allows the animal to absorb more of the phosphorus within the feed.

There is also an environmental advantage to maximizing the amount of phosphorus that an animal can absorb. Once excreted, undigested phosphorus seeps into the ground and ultimately makes its way to rivers, lakes, and the ocean. Given sufficient light, nutrients from the runoff fertilize algae and other aquatic plants. This produces huge algal blooms that deplete the water of oxygen. Laws that discourage phosphorus pollution in some states have contributed to the increased use of phytase over the years. Maryland, for example, mandates that phytase be used in poultry feed.

Functions (Note 1)


  1. Carbohydrases

Carbohydrases improve the digestibility of carbohydrates in feed, thus increasing the amount of energy an animal can use to develop muscle and grow. Types of carbohydrases include amylase, which breaks down starch into fructose, maltose, glucose, and other simple sugars; and xylanase, which digests complex carbohydrates found in dietary fiber. Although chickens naturally produce enzymes that aid in the digestion of carbohydrates, they do not produce all the enzymes needed to break down fiber completely.


  1. Proteases

Proteases break down complex proteins into shorter proteins, called peptides, and amino acids, which are the building blocks of protein. They are also capable of taking apart proteins that bind starch within feed ingredients, thus making more of the energy found in starch available to the animal.

BRI’s natural enzyme feed additive, Versazyme, is a broad spectrum protease that degrades many protein substrates. A 2001 trial showed that chickens that were fed a 2% lower protein diet supplemented with Versazyme grew as large as birds that were fed a standard diet containing more protein.


While thousands of enzymes have been identified and several hundred are available commercially, only a fraction of these are produced on an industrial scale. In next week’s blog post, we will discuss how biotechnology has enabled the mass production and application of enzymes in the agriculture industry.


Benefits of enzymes

  1. To Poultry


  1. In Digestibility
  2. Enhances the feed intake and efficiency, growth rate and productivity.
  3. Increases the energy value of cereal feed stuffs. More nutrients are made

available by hydrolysing fibrous material.

  1. Better digestibility of feed ingredients by better feed conversion.
  2. Enzymes act as supplement to the normal digestive enzymes especially during

stress condition.

  1. Reduces antinutritional products like tannins, saponin and goitrogen.
  2. Promotes weight gain and overall improved performance.
  3. Release minerals for assimilation – eg: Ca, Mg, Zn, P etc.
  4. Stabilization of microbial flora by making these nutrients readily available to them.
  5. Checks chelating of minerals such as Zn, Mn, Fe, Ca, K with phytic acid, less

chelation means more mineral availability.

  1. Prevents precipitation of pentacalcium phosphate and there by improves

absorption of calcium and phosphorus.


  1. In Animal Health
  2. Improvement in animal hygiene and health.
  3. Corrects digestive disorders especially when birds are crowded.
  4. Fattening performance is increased.
  5. Prevents damages to chicken anaemia agent.
  6. Prevents damages to chicken anaemia agent.
  7. Checks cellular damages caused by toxins.
  8. Promotes growth to bones.
  9. Prevents diarrhoea due to poor fibre digetion.
  10. Minimizes excreta, water droppings and of ammonia.
  11. Reduces viscosity and ammonia level in intestine.


  1. In Poultry Product
  2. Increases egg production and hatchability in layers.
  3. Egg quality is also maintained. More cleanly eggs and with thick shell is


  1. Improves flock uniformity leading to more consistent sized birds.
  2. Improved slaughter results, high carcass weights and better grading.
  3. Genetic Potential of birds can be explored enabling them to consume more

quality of feed to achieve maximum growth and production.

  1. To feed
  2. Greater flexibility in feed formulation.
  3. Readily available material can be advantageously utilized.
  4. Use of newly harvested grains.
  5. Use of cheaper raw materials as choice of raw material is increased. Barley can

be easily used in place of wheat.

  1. Feed additives hold promise to lower the overall production cost. Better profits as

inexpensive feed stuffs can be taken.

  1. Cereal replacement due to use of enzymes. High M.E. cereals can be fully

replaced by low M.E. cereals without compromising growth performance.

  1. Elimination of anti-nutritional factors from feed and feed ingredients eg:

galactoside and pectins etc.

  1. To environment
  2. Reduction in manure volume.
  3. Reduced nitrogen and Phosphorus exertion.
  4. Less environmental waste and therefore less pollution.
  5. Reduced environmental stress resulting from reduced litter volume.

Use of Enzymes in Feed

™To enhance the feed intake and efficiency growth rate & productivity, by

overcoming many nutritional problems and correcting digestive disorders

especially when birds are crowded

™To increase the energy value of cereal feedstuffs. More nutrients are made

available by hydrolysing fibrous material

™To minimise excreta, waterly dropping and ammonia

™To reduce anti-nutritional products like tannins, saponins and goitrogens

™To provide choice of raw materials. For eg. Barley, which was not earlier used,

is now successfully used with enzymes.

™To promote faster growth by increasing feed efficiency and promoting weight


™To increase egg production and hatchability in layers

™To reduce early mortality due to the problems associated with harmful moulds

andaflatoxin in poultry feeds.


Enzyme-added feed provide additional option where certain feedstuffs are in short


Readily available materials can be advatageously utilised

Price advantage over more traditional and inexpensive feedstuffs can be taken

As growth promoters, feed enzyme additives hold promise to lower the overall

production costs while improving the performance of birds

The genetic potential of birds can be explored, enabling them to consume more

quality of feed to achieve maximum growth and production.