Feed & Additive Magazine Issue 3 April 2021

ISSUE FOCUS FEED & ADDITIVE MAGAZINE April 2021 53 tal eutrophication. High ammonia levels in animal sheds can affect animal welfare and performance and pose a risk to human health. While it’s easy to focus on livestock production as the villain for many environmental woes, there is another 82 to 93% of GHG’s attributable to indus- tries other than livestock. However, livestock pro- duction is in the environmental crosshairs of govern- ments and several initiatives have been implemented to combat increasing emissions e.g. EU Directive 2010/75/EU or the stance taken by the Netherlands to aggressively decrease nitrogen pollution. While poultry and egg production are amongst the lowest producers of GHG’s, the industry still has an obligation to do all it can to reduce its environmen- tal impact. In many countries the poultry industry is tackling this problem head-on and improving nitro- gen utilisation is a focus. IMPROVING NITROGEN UTILISATION VIA NUTRITION Nutrition is a key focus to improve nitrogen utilisa- tion. For example, we can use more digestible ingredi- ents, alternative protein sources or add more essential amino acids to improve the efficiency of nitrogen use. We can also look at reducing dietary crude protein (CP) by using nitrogen-balanced diets based on digestible amino acids. Insoluble fibre can influence digestibil- ity of protein and other nutrients, but consideration needs to be given to fibre type if used in fibre-rich diets. Multi-phase feeding programmes can balance the diet to changing nutritional demands of the birds and have been shown to have no detrimental impact on perfor- mance while lowering overall faecal nitrogen content. THE ROLE OF FEED ADDITIVES Feed additives are a diverse group including en- zymes, organic acids, probiotics, phytogenics, etc. Enzymes clearly have a role improving nutrient util- isation in poultry feed and have been used for many years. Proteases can support the reduction of dietary crude protein and reduced nitrogen excretion via im- proving protein digestion. Many types of feed additive have typically been used with a focus to support intestinal health. By helping birds to have a balanced microbiota, gut health and therefore feed utilisation is improved. It is a well-told story of poor gut health in birds leading to protein fermentation in the hindgut and subsequent prolif- eration of Clostridium perfringens and production of endotoxin resulting in necrotic enteritis. However, as the importance of environmental sustainability grows, so feed additives look to broaden the scope of their modes of action beyond managing the gut microbiota alone, from modulating specific immune