The use of enzymes in monogastric diets have evolved considerably. But ongoing research brings us new insights in how to apply them effectively and which factors influence the mode of action of feed enzymes.
This was one of the conclusions from the 1st Global Feed Enzymes Forum, organised recently by the DSM/Novozymes alliance. The forum was a combination of sharing the latest scientific and technological advances in feed enzymes.
Feed enzymes are extremely important for livestock diets, as major enzymes like phytase, proteases and carbohydrases make sure the nutrients in the feed materials can be extracted and digested by the animal after consumption. But diets evolve, as more and different raw materials are increasingly used in animal diets and more feed additives are added in the form of a mixture. Also technological advances have been made in processing of the feed (pelleting) and more insights have been gained on the effect of feed on gut health and how this in turn can affect the digestibility of feed material at different parts of the intestinal tract. Last but not least, animal diets have to become future-proof, to for example withstand environmental challenges that intensive livestock may bring and the antibiotic free movement that is happening at a global level.
At the Global Feed Enzymes Forum, around 55 experts gathered to discuss the challenges and the outcomes of some recent studies that have been done. Photo: Shutterstock
Differences between pigs and poultry
All these factors make us review, assess and innovate the way we use feed enzymes. At the Global Feed Enzymes Forum, around 55 experts gathered to discuss the challenges and the outcomes of some recent studies that have been done. Some of these insights were shared with All About Feed.
The right enzyme application and knowing which dosage to use requires good understanding of digestibility processes in the animal, a topic that Layi Adeola from Purdue University in the US further addressed. He spoke about the differences in how we can look at amino acid digestibility and how pigs and poultry deal with this in a distinct manner. “For starters, we have to work with the ileal digestibility, because if we just measure the amino acids in faeces of pigs and poultry we get a disrupted amino acid profile.” Adeola and his team questioned whether amino acid digestibility differs in pigs and poultry, looking at different amino acids and different feed ingredients. “For lysine digestibility for example we saw a difference. For threonine, pigs seem to have a higher standardised ileal digestibility (SID in %) than broilers. However, we saw that for the feed ingredients full-fat canola seed / solvent-extracted canola meal and expeller-derived canola meal ingredients, the digestibility was higher in broilers. We will conduct more trials to further look into these differences,” Adeola explained.
Introduction of RONOLab
At the 1st Global Feed Enzymes Forum a new tool under development was presented: RONOLab. This tool / platform is able to measure specifically selected enzymes. The first developed assay within this tool is made for HiPhos phytase. This means the assay doesn’t detect other plant phytases or other commercial phytases in the sample. The entire measurement procedure takes about 1 hour, including a 40 minute incubation step. The results are given in FYT/kg. One FYT (phytase) unit is defined as the amount of enzyme that liberates one µmol of inorganic phosphate from sodium phytate per minute at pH 5.5 and 37ºC. Compared to other assays, this tool measures the active enzyme in the sample, not the activity.
Ca:P ratios: Does this make sense?
Rosalina Angel brought another important topic to the table: the Ca:P ratios. In her presentation she delved into ways to optimise phosphorous (P) digestibility through better understanding of Calcium and limestone. “Working with a total Ca:P, does this make sense?” Angel said. According to her, the only thing that is important is the amount of P and Ca that is available to use / be metabolised by the animal. “Total values mean nothing.” So new studies are focused on validating the recommendations and fine-tune the ratio that they are using. “We therefore also looked into the effect of the type of Calcium and P used. In a corn diet for poultry we used a 0.04% Ca and P limestone. Hence, we added different phytase levels in diets with and without the limestone. Different particle sizes of the limestone were also studied. We saw a difference in particle size on the effect of phytase (0.0150mm against 0.806mm),” Angel explained.
Impact of pelleting
Reza Abdollahi from Massey University in New Zealand delved into feed processing. “There are differences between pelleted feed and mash feed when it comes to ileal nutrient digestibility. Pelleting feed requires a lot of heat and this can have negative effects on the nutrients. Pelleting can reduce nutrient digestibility of starch, fat and calcium in sorghum diets for example. In wheat diets, pelleting pretty much reduces digestibility in all nutrients,” Abdollahi explained. So why do we pellet the feed? “We simply see that animals have a higher feed intake when they eat pellets, which in turn leads too better weight gain, despite the nutrient losses than can happen.” He further addresses that this may impact gut development in poultry, so this is a challenge for nutritionists. “Studies showed that pelleted feed can reduce the size of the digestive tract (in %). This means that more feed has to be pushed through a smaller digestive tract, which is a challenge for gut health.”
Joe Moritz from West Virginia University in the US delved deeper into the effect of feed processing. Trials done with his team with 3 different types of phytase showed that when temperatures in the conditioner increased, also the live weight gain and a decreased activity of the exogenous phytase was seen. Post-pellet liquid phytase addition can therefore be an option, but also can lead to uneven distribution of the enzyme on the pellet, and hence uneven distribution of the enzyme at bird level.
Effect enzymes of amino acids
Aaron Cowieson, principal scientist at DSM Nutritional Products concluded the seminar with an overview on how all the challenges and influences of feed ingredients relate to enzymes in animal diets. He explained what enzymes do fundamentally. “Substrates are very specific and require a certain enzyme, but the outcomes for the animal overlap, whether you use a protease or a phytase for example.” An overlapping effect of different types of enzymes include a better digestibility of fat, protein and Calcium for example. Cowieson also addressed that it is important to know as much as possible about the quality and value of the feed ingredients. “Only then you can assess the efficacy of the enzyme.” He further explained the influence that xylanase, phytase and proteases have on the amino acid (AA) digestibility. AAs are a focal nutrient for protease, but not for other enzymes. Many papers have looked into this and the major conclusions are that xylanase improves the digestibility of all AAs, phytase shows a different picture and seem to show a bigger effect for threonine for example. Proteases also suggest a more specific pattern (compared to xylanase), although different from the phytase response.
The DSM/Novozymes alliance was formed in 2001 and combines world leading competencies and technologies of the 2 companies to deliver feed enzyme innovation to the customers. Novozymes specialises in enzyme screening and development, enzyme product formulation and enzyme production and DSM Nutritional Products brings its command of animal nutrition and feed technology to the alliance table, as well as its global reach in the feed industry via the DSM technical marketing team. DSM is named among the world leaders in the Materials industry group in the Dow Jones Sustainability World Index published in September and recently made no.2 on Fortune’s ‘Change the World’ List.