By Rick Kleyn, poultry nutritionist
Sustainable broiler production should be at the heart of our endeavours as an industry, as this is the only way in which we will be able to ensure the wellbeing of our descendants. Importantly, sustainability is now recognized to comprise three distinct components: we need to be environmentally aware, both in terms of our total demand for resources and the polluting nature of animal production; ethically we need to consider both human and animal welfare and we need to ensure that our systems are economically robust enough to continue to meet the demands of our people (food security). These elements are referred to as the three E’s of sustainability. The temptation to focus on a single area at the expense of the others is short-sighted and not very constructive. Often an improvement in one area of suitability has a negative impact on another, adding a further complication.
Protein is likely to become more constrained than energy, simply because yields of proteinaceous crops are considerably lower than those of cereal grains. Broadly, we are aware that protein efficiency improves with faster growth rates (alternative production systems are less efficient, largely because the birds grow more slowly) and that broiler meat is able to be produced far more efficiently than any other animal protein. The second major consideration in protein utilisation is ensuring gut health and function, through which a reduction in undigested material and enhanced nutrient uptake can be can be achieved. Our use of a range of endogenous feed enzymes has direct bearing on both of these.
A key aspect of protein efficiency is to ensure that we use optimal dietary amino acid and crude protein levels in our diets. This goes beyond the obvious of feeding the correct diet to broilers at each stage of production and ensuring that our ingredients are correctly processed. Recent research has highlighted that dietary protein levels can be dropped through the application of enhanced ideal amino acid profiles and the use of an ever-widening range crystalline (synthetic) amino acids. Currently this may not always be a cost-effective practice but it does lead to reduced protein demand as well as a reduction in manure nitrogen. This positively impacts on the pollution levels brought about through broiler meat production and leads to an improvement in welfare. Nutritionists are faced with a quandary though. Modern broiler genotypes respond to increased levels of dietary protein in a manner we previously would not have though possible. Under the correct conditions, increased dietary protein levels give rise to enhanced field performance and increased returns, although they do not always result in the most efficient protein utilization.
Judicious use of a range of endogenous enzymes plays a huge rule in protein utilization and broiler welfare. Enzymes are without doubt the most effective feed additives in our arsenal, and they have the added benefit that in most instances they are cost effective. Enzymes have both direct and indirect modes of action in that they may directly enhance nutrient digestibility, while at the same time modulating gut health and function. Precision enzyme use is complicated by the fact that the bird, the diet is being fed and the enzymatic landscape are all dynamic (they change throughout the broiler production cycle). Added to this is the fact that enzyme response is not necessarily linear and that the ‘additivity’ of combinations of enzymes is not yet well understood. All of these aspects need to be considered when formulating broiler diets. Should the enhancement in nutrient digestion (often called the ‘lift’) be overestimated, broiler performance will suffer, while under-estimating the nutrient contribution of a blend of enzymes represent lost opportunity in terms of sustainability.
There is no ideal way to handle enzymes when formulating diets and several mechanisms have been applied with good effect over the years. Of significance is the fact that the mere inclusion of an enzyme in a diet may alter the substrate level in that diet, making some form of iterative analyses essential. Formulating with ingredients where the expected improvement in nutrient digestibility is included is a method that is widely, although this tends to ignore any changes in enzyme efficiency as the bird ages. The creation of multiple forms of a single ingredient in a formulation system can cause confusion in accounting and logistics departments. Adding an enzyme matrix to a premix (especially if the enzymes are included in the premix) works well and allows for the use of different values for different ages or enzyme combinations. There are also some things that we know we should not do. First, any system applied should not be overly complicated as this leads to errors and confusion. Secondly, simply adding enzymes ‘on top’ of an existing formulation seldom gives a desired response. Lastly, the use of a single solution (matrix) for all diets and all stages of production is a shortcoming.
Formulating diets for broilers has moved on from the production of least-cost diets. Nutritionist, producers and consumers will need to consider all aspects of the sustainability issue. A balanced approach is the only way that we will ensure that the broiler industry continues to fulfil its mandate to produce adequate amounts of suitable product.
Elanco will be hosting a broiler nutrition webinar with two purposes in mind. These are the transfer of knowledge, concepts and ideas and interactive discussion between participants. Groups will be kept small in order to maximize the collaborative nature of the event. Please register at www.MyElanco.co.uk to receive an invitation.
