AUTHORS: Howard Simmins - InSci Ltd., Cassio Villela - Sr. Technical Mkt. Specialist, Novus International
Due to the inherent variability in nutrient levels and availability in feedstuffs, providing a balanced diet to animals at different stages of their production can be challenging. The simplest approach is to provide excess nutrients, which ensures the majority of animals will receive at least the minimum required for growth. However, the level of excess rarely offers the most cost-effective, efficient growth, and it can raise health, performance and environmental risks. Controlling the variability in feedstuffs by supplementing with protease allows producers to use a range of ingredients that may be higher in anti-nutritional factors (ANF) and control the level of excess nutrients offered to animals.
The greater the level of undigested protein, as measured by amino acid digestibility, the more variability a particular raw material will exhibit. Variability in amino acid digestibility is common to all feedstuffs, and varies among different types. Both the content percentage and coefficient of variation (CV) of digestible lysine and methionine from commonly used feedstuffs are shown in Table 1. This indicates the range can be wide and should be considered.
Role of Protease
Protease is known to reduce the proportion of indigestible amino acids in feedstuffs, resulting in a corresponding increase in digestible amino acids. Generally, the more indigestible the level of amino acid present, the greater the increase in digestibility when protease is added. Research has shown standardized ileal digestibility (SID) improvements with protease, added as CIBENZA® DP100 protease feed supplement, in every plant and animal feedstuff that has been evaluated.
Similar results were seen when a protease was added in the presence of phytase and xylanase. It is important to note the uplift in amino acid digestibility in the presence of phytase and xylanase, without protease present, was minimal. The mode of action of protease is different from the other major enzymes and has the potential to be additive.
Protease also reduces the effects of ANFs present in proteins, thus helping improve amino acid digestibility. The improvement in SID, when protease is used, may be related to the level of an ANF, such as a trypsin inhibitor. Researchers have explored the combination of trypsin inhibitor and SID% and found the greater the level of the trypsin inhibitor substrate on which the protease has to operate, the greater the SID% improvement.
By reducing the levels of undigested protein, this establishes the conditions for a healthier gut, reduced nitrogenous excretion and lower protein diets, all of which have the potential to improve performance and reduce feed and production costs. This functionality is unique to protease, which is why it has been called the "next amino acid."
Research has demonstrated the benefits of improved amino acid availability when protease is used. One study showed that the reduction in the total amino acid content of a feed was compensated by the increase in their digestibility through the use of protease, and animal performance was not compromised.
Other benefits from protease may be in the degradation of fiber (possibly through the disruption of cell wall associated protein), which facilitates the microbial colonization of the substrate and reduces the total tract flow of sugars from non-diffusible sugar-peptide (NSP) fractions. The energy released may then be accessed by the animal. Each feedstuff has a different physical structure, and the nutritional benefits in breaking that structure may extend beyond amino acid digestibility.
The potential to feed monogastric animals closer to their optimum protein requirements, with the addition of protease in diets, has multiple benefits. One economically important example is the management of necrotic enteritis (NE) in broiler chickens. The reduction of the level of undigested protein in the hind gut, by feeding lower protein diets through the use of synthetic amino acids and protease in combination, could reduce the risk of NE in poultry. Caecal ammonia has been shown to reduce with protease, which lessens the risk of high ammonia levels in buildings making animals less liable to respiratory disease.
Protease potential benefits include:
- Reduction in excess protein that could otherwise become a fermentation substrate in the lower part of the GI tract when broilers are fed a high protein diet. This would result in breakdown products such as phenols, amines, ammonia and indoles, which in turn, increase the pH.
- Reduction in ANFs, such as trypsin inhibitors, which likewise might provide conditions to predispose the growth of C. perfringens, and thus NE.
- Reduction in higher ammonia levels in animal buildings, which could predispose the animals to risk of respiratory diseases.
Nutrient variability in feedstuffs creates a challenge in providing a balanced diet for monogastrics and potentially raises the price of feed, which is already a major cost in animal production systems. Measuring nutrients accurately and controlling the variability in feedstuffs through the supplementation of a high-quality protease, such as CIBENZA DP100 feed supplement, allows for greater use of ingredients that may be higher in ANFs, without undue nutrient excess. It allows for precision feed formulation through better balanced protein and energy, supported by the judicious use of synthetic amino acids.
References are available upon request.