Metabolisable energy (ME) is the energy that comes from feed raw materials which is available for animal maintenance and growth. Non-starch polysaccharide (NSP) degrading enzymes release bound energy from the feed ingredients by breaking down fibre. This process also releases other useful nutrients such as amino acids. As the price of energy is constantly increasing, using NSP enzymes to release energy already present in the feed but not yet available to the animal makes sound financial sense.
Hostazym X and raw material energy matrix
The amount of energy and other nutrients released from a raw material by an enzyme is measured, and we call this the matrix value. All NSP enzymes, such as Hostazym X, have an associated matrix value. Nutritionists can use the matrix value of the enzyme to reformulate diets and in many cases, this reformulation reduces the cost of the feed while being able to deliver the same level of zootechnical performance in the animal.
It is well established that Hostazym X can reduce feed costs in poultry and swine by up to €28/metric tonne when the full (standard) matrix values are applied to the feed formulations. This is dependent on the types of raw materials used and the nutritionist having a good understanding of the ME value of each raw material in their database.
Hostazym X application
Hostazym X can be applied using partial or full matrix values. Releasing the full matrix value of ME from the feed by adding Hostazym X will only be possible if the raw materials have a sufficient ME content to begin with. Knowing the ME value of the raw material is therefore key when applying Hostazym X energy matrix values to allow for optimal production results.
Some nutritionists use the CVB (Dutch Central Animal Feed Bureau which is a well-recognised standard) for nutritional matrix values of raw materials. Other nutritionists have their own values calculated using the World Poultry Science Association (WPSA) correction tables which are based on laboratory analyses of raw materials. There is no single value for ME for each raw material which is currently accepted as a global standard. When ME values are reassessed based on theoretical calculations (e.g., WPSA correction tables) and not on a standardised system such as CVB, the energy differences of each raw material become clear and this can impact the overall nutritional composition of the feed.
When the CVB raw material matrix values (Table 1) are applied to a basic poultry finisher feed ration (Table 2), the potential impact of over- or underestimating the ME of each raw material in the feed, as well as the total feed ME, becomes clear. The bottom line of Table 2 shows the net difference in ME versus the published CVB values as +141 kCal or - 138 kCal. This energy excess or deficit can have a big impact on the ratio of digestible lysine to energy, consequently affecting feed intake and therefore impacting animal performance.
Hostazym X can be added to the diet in two ways. As already mentioned, it can be used to reduce feed costs by taking the extra energy and other nutrients into account when formulating the diet. Alternatively, when no matrix value is used, Hostazym X can be applied 'over the top' of the feed formulation. This means that the enzyme is used to improve the feed conversion and meat yield from the carcass by delivering extra energy and nutrients to the animal. This approach is of specific interest in integrated poultry businesses where more value can be realised throughout the whole production process, from raw materials through to slaughter.
Over the top application in practice - trial data from Canada
In initial customer trials with Hostazym X, an over the top application would always be recommended, especially when making a comparison with a competitor product to avoid any unexpected trial results. This approach reduces the risk of any potential over- or underestimation of raw material ME values. The real benefit of the enzyme can therefore be seen in the improved feed conversion ratio or body weight, or a combination of both.
This approach was applied in a series of four trials completed in 2021 in a large poultry integration in Western Canada with Hostazym X versus a competitor NSP degrading enzyme product (Table 3). Hostazym X was applied over the top, replacing the competitor enzyme.
Summary of Hostazym X benefits versus a competitor with over the top application in the field:
- 146 g extra body weight at 38 days
- FCR improvement of 5 points
- Associated reduction in CO2 emissions per bird
- FCR adjusted for weight (2.3 kg): 9-point improvement
- Mortality reduction of 1.11%
- EPEF increase of 34 points
Supplying broilers with a perfectly balanced diet containing all the nutrients they require without any excess is the ultimate goal of the nutritionist. Knowing the exact amount of ME in each batch of raw material is impossible so estimations have to be made. This can lead to an imbalance of the various nutrients which might affect intake levels or overall performance.
Enzymes that break down the fibre portion of the diet to release bound energy and nutrients (NSP enzymes) are invaluable, especially when considering the rising price of raw materials. The released energy and nutrients can be included in the diet formulation to reduce the cost of the feed. To minimise the risk of any deficiencies, enzymes can be used over the top to deliver additional energy and nutrients, boosting performance and carcass yield.
Globally accepted data for raw material matrix values can be found at: