Aquafeed Vol 12 Issue 1 2020

Page 45

45

Unlocking phytate potential through NIR technology Sophie Lee, William Greenwood, AB Vista

The phytate challenge Significant progress has been made to reduce or replace fishmeal in the diets of many aquatic species through the use of plant-derived proteins. Although plant sources such as soy have a high protein content, they also contain anti-nutritional factors (ANF) which have a negative effect on feed efficiency and growth performance. One of the most prevalent ANFs is phytate, as it is present in all plant-based feedstuffs. It is not only a source of unavailable phosphorus (P) and inositol, but it also binds to other minerals and proteins present in the gastrointestinal tract rendering these nutrients unavailable for digestion, and consequently leading to their excretion into waters. Protein and P excretion in aqua production is one of the most important pollutant factors and may limit the survival and number of fish allowed to be harvested in one area. Phytases are enzymes that breakdown phytate, thereby making phytate-P and bound nutrients more

available to the animal. By alleviating the anti-nutritional effect of phytate, phytase encourages growth and reduces nutrient losses. Understanding the phytate level is vital because this determines how much phytase can be added to feed.

Near infrared spectroscopy (NIR), a tool to unlock phytate potential? NIR technology uses near infra-red light to analyze raw materials and complete feed to predict its nutritional value. Traditionally it has been used to measure primarily fiber, protein and moisture levels, but advances in NIR technology have enabled the analysis of other parameters such as phytate. The phytate level varies between different feedstuffs and within a single raw material. Figure 1 demonstrates the variation in phytate content among different plantproteins. If not accounted for in the feed formulation, variations in dietary phytate can result in reduced animal performance, impacting producer profits.

Aquafeed: Advances in Processing & Formulation Vol 12 Issue 1 2020