The main contributors to spiraling feed costs are numerous: increased demand for food due to continual exponential growth in world population, increased meat consumption, low world stocks of feed ingredients and reprioritization of land from food use to biofuel due to government energy security and climate policies.
Adverse weather conditions also have a significant impact on crop yields, fuelling speculation in the commodity markets and further driving feed prices upwards. All of these factors have contributed to a doubling of the feed cost in the UK alone (Figure 1), for example, with similar rises seen across the globe over the last five years.
The commercial nutritionist’s role is to help meet this increased demand for food/meat production at affordable prices for consumers; with sustained profitability for producers. The question is how do we meet this challenge especially in a highly competitive market place? This is a continual process of optimizing productivity and improving feed efficiency through the considered application of existing and innovative technology. This can be summarized by three key objectives:
- Feed design must be nutritionally accurate, and capable of being milled to a high standard; this subsequently provides a well-presented diet, complimentary to the producer’s management capability and choice of genetics
- Diet design must enable the broiler to extract as much nutritive value from the composite feed ingredients as possible, maximizing digestion and absorption potential
- The diet should help to augment the gut flora, digestive passage and the immune performance of the gut
Genetics and feed design
Sixty years of genetic improvements to the broiler chicken have resulted in significant improvements in body weights and body composition.
The continual selection for a high genetic potential to lay down lean tissue together with fast growth rates has set its own challenges. These have generally been overcome through good nutrition management or genetic improvement.
So how can we feed this modern bird and what improvements do we have to match feed design to genetic potential (Figure 2)?
We must be able to optimize nutrient intake and manage the feed schedule by balancing the feed mill and farm operational efficiency with broiler nutrient requirements. This requires the use of multiple feeds within a feeding regime to accurately match a bird’s requirements and minimize nutrient waste. This requires much greater control over nutrient intake, starting with careful use of energy rich raw materials and key building block nutrients such as protein, amino acids and minerals.
Computer models can facilitate this task by optimizing efficiencies and nutritional strategies, reviewing the output and fine tuning the model; this process can be repeated until a suitable solution is found that can be implemented.
The physical quality of the feed can also impact significantly on the performance of the bird. Live weight gain and feed conversion can be greatly reduced by dusty feed versus a suitable pellet form or a mash that has been appropriately milled to minimize this effect. There are numerous publications that demonstrate the importance of feed presentation and why it is even more critical when economic costs are spiraling.
Extract more nutrition from feed ingredients
Figure 3 illustrates the extra release of energy yet to be realized from three common feed ingredients; the challenge is how to realize this energy.
The use of enzymes in feeds has been well demonstrated in recent years but the effective capture of their commercial value is not so well confirmed.
Non-starch polysaccharides are considered to be antinutritional and while being largely indigestible, they also create an adverse environment in the small intestine and can lock up the availability of nutrients such as amino acids, vitamins, and trace minerals. The use of a specific non-starch polysaccharides enzyme such as β-glucanase, xylanase, is effective in breaking down these large polysaccharides to smaller molecules, thereby reducing the viscosity of the digesta and creating access points to the nutrients that were previously unavailable.
Further improvements in digestibility can also be made when solid state fermentation derived multi-enzymes having components such as galactosidases, pectinases, proteases, lipases, hemicellulases, and α-amylase are used. The addition of these enzymes makes it then possible for the bird to utilize a proportion of the extra energy released from the raw material substrates within the feed via a reduction in digesta viscosity which, in turn, increases protein digestibility and trace mineral availability; and thus increases feed efficiency.
Recent commercial work demonstrates that the net return using specific non-starch polysaccharides enzymes realizes a benefit of 4.5 percent reduction in overall feed cost. A further net reduction of 1.1 percent in terms of feed costs can be achieved if a multi enzyme complex is used; this brings a total feed cost saving of 5.6 percent.
The world cannot afford to allow chickens to continue to extract so little metabolizable energy from the carbohydrate component of plant ingredients such as soya where there is a potential 69 percent of unrealized metabolizable energy being excreted. We need to increase focus on the nutritive value of many other ingredients that are better suited than soya bean in developing tropical countries. It is imperative to continue innovation, research and development of enzymes such as cellulases, proteases and lipase, so that all nutrients are digested effectively.
Further energy optimization tools are also available, for example lysophospholipids. Fat digestion can be limiting in the broiler, especially in the first five to seven days of its life cycle. Whilst bile and dietary lecithin aid digestion of lipids, the addition of lysophospholipids improve lipid emulsification and improves micelle production, these smaller micelles also have a superior affinity for the cell membranes of the villi. The absorption capability of the gut is subsequently improved for lipid digestion when compared to relying on normal dietary lecithin. Recent work has demonstrated that the net feed cost could be further reduced by 1.5 percent.
Managing gut microflora and the immune response
It is well established that a healthy gut is defined by a positive, balanced gut flora. This in turn reduces biological maintenance cost for the bird and potentially improves immune status resulting in improved feed efficiency. Products termed "gut health enhancers" that have been demonstrated to exert an influence in this area are: yeasts, probiotics, organic acids, essential oils, plant extracts, omega-3 fatty acids, etc.
All of these products can help modulate or influence the type of bacteria that are present within the gut system and stop proliferation of unwanted pathogenic bacteria. Gut health is essentially the first line of defense against disease but also critical for optimal nutrition status within the broiler.
In summary, it is essential when faced with high feed costs, inferior raw materials, even adverse weather conditions that an appropriate feeding program is designed which mitigates all of these biotic and abiotic influences.
These challenges drive the poultry industry forward and create innovation and make people think dynamically. The current situation should not be viewed as a crisis but as the chance to take poultry nutrition to a higher level and make further efficiency gains.