Improving Feed Digestibility and Nutrient Breakdown with Exogenous Enzymes

The feed can account for up to 70% of operating costs for poultry producers. Unfortunately, issues with climate change, international conflict, and supply chain challenges are only adding to this. This has left many producers looking for alternative and innovative solutions that will not only help lessen this financial burden but also help improve animal performance.

Feedstuff Nutritional Challenges

Although poultry is quite efficient at converting feed to protein – especially compared to some other livestock species – a significant portion of energy and nutrients in the feed is never fully digested and gets excreted into manure. This is partially due to the feed matrix and the bird’s ability to fully digest grains, seeds, meals, and other feedstuffs. Plant-based ingredients are commonly used in poultry feeds, but energy and nutrient availability vary depending on the source. Energy can be one of the most expensive inputs in poultry diets, so maximising its use in poultry feed improves efficiency and has the potential to lower feed costs.

Plants store energy-providing nutrients (like carbohydrates) as simple sugars, starch, and non-starch polysaccharides (NSPs). While simple sugars and starch are readily digested by poultry, NSPs are not because poultry does not produce the adequate digestive enzymes required to break down these complex molecular formations into absorbable carbohydrates.

NSPs can be categorised as insoluble or soluble, each impacts nutrient digestibility differently. Insoluble NSPs occupy space in the digestive tract that can create a physical barrier against digestive enzymes and nutrients. Soluble NSPs increase the viscosity of digestive tract contents, disrupting the digestibility and absorption of proteins, lipids, and other carbohydrates. The NSP content in poultry feed ingredients ranges from approximately 10 to 30%, with higher amounts of NSPs typically found in cheaper, non-conventional feedstuffs and agricultural waste by products.

Phosphorus is an important nutrient for growth and production. It is abundantly present in a wide variety of plant-based feedstuffs, but phytic acid, which is the storage form of phosphorus in plants, is not easily digested by poultry. Because of this, phosphorus is often supplemented in poultry diets as an inorganic mineral salt. However, phytic acid can negatively interact with amino acids and minerals, reducing nutrient digestibility and rendering minerals unavailable for absorption. Additionally, supplementing inorganic phosphorus in poultry diets to address poor feedstuff utilisation contributes to the phosphorus pollution of soil and water, largely due to the excessive amounts excreted into poultry manure that is then used as crop fertilizer.