The most economical feed formulation for meat production in monogastric animals seeks to optimize ingredients and processing for the most efficient lean tissue deposition. Previous FEED INTERNATIONAL articles on 'monogastric basics' of formulation (March and October 2005) focused on the basics of economical formulation with dietary energy and amino acids. This article brings these approaches together in strategies for computerized or computer-aided formulation to optimize reduction in feed costs.

Starting with a blank screen in which a hypothetical feed formulation operation is using no cost-savings strategies, the first action to reduce the actual cost of feed is to try to purchase ingredients in bulk and pay at the world market price. Beyond this, there are a range of viable cost reduction strategies using conventional diet formulation software. We can use broiler chicken production as the main example, but the principles mostly apply as well to pig and turkey production.

We will first assume that we are feeding broilers with total amino acids (AA) and protein in line with 'book values' (National Research Council, 1994). Such values would provide excellent performance in many situations with US-style maize-soya diets. A recent broiler trial using unaltered NRC maize-soya diets provided 3.63 kg body weight and 1.69 feed:gain at 7 weeks of age on mash feed in floor pens with industry-style housing.

Departing from this basic diet set, we can make a number of cost-saving changes. However, in practice, please be deliberate and careful in experimenting with these changes--do not make major dietary changes for millions of birds at once. Also, most formulators, and even formally educated nutritionists, are self-taught in computer-generated diet formulation. They may not be in the habit of using formulation and animal growth modeling software as a tool for formulation exploration.

Although a number of variables complicate specific situations, savings can be significant in developing practical diets. In my personal experience, one turkey operation in the US reformulated diets and the company achieved better bird performance and 15% cost savings on feed. In a layer operation in India that was providing too many grams of feed per day, ‘over-formulating' for protein, and not using computer formulation, there was as much as 40% in cost savings. Reformulation probably also enhanced bird performance. However, in a well-run company, currently computer formulating, there may be very little left to save. Please keep in mind that the savings seen are almost entirely profit; as for the most part, there is little cost associated with such changes as those recommended below.

Replace ingredient traditions with information: The best example of a 'formulation tradition' is fish meal or fish meal replacements. Use of fish meal resulted in improved performance due to its value as a selenium source and improved amino acid balance. The introduction of computer formulas removed fish meal from monogastric diets in many countries as it was not cost effective. Other products that I have seen fed without value include some concentrates, as noted below, and alfalfa meal. Alfalfa meal need only be fed if low levels of maize are fed to layers. In a completely wheat-based diet, 2.5% alfalfa meal can be fed for yolk coloration. This can be reduced based on how much corn is used for the grain portion of the diet.

Avoid concentrates: Concentrates are generally very expensive, constituting as much as 10% of the diet cost, but provide relatively little value relative to their cost in the diet. In many cases they provide some amino acids and perhaps a concentrated source of protein, such as in corn gluten meal. While there is nothing wrong with these products from a nutrition standpoint, they generally are not characterized to a degree specific enough to be useful in the computer-formulated diet. Usually, they come into use when expertise and computer formulas are not available or quantity needs are too small to justify individual ingredients such as lysine or methionine. The best way to evaluate a concentrate is to enter its values into the formulation database as an ingredient with a price, just like fish meal, and see whether the formulation program selects the product over individual ingredients in building a particular diet.

Avoid over-formulation: Over-formulation and over-feeding generally result from a lack of knowledge or fear of making changes. Over-feeding almost always results in best bird performance, but also costs extra money. This is why computer formulation was introduced, not to improve bird performance, but to save feed costs.

Avoid unnecessary additives: The formulator also can save money by reducing use of unnecessary additives. Phytase, for example, is a legitimate product that definitely works, although its use is inappropriate in many cases. Much of the phytase used in the world shows absolutely no response in the birds fed. Phytase acts to free up bound phosphorus from grain sources. If the phosphorus requirement for a diet is 0.40% and 0.44% is fed, then phytase will have no effect on performance. If 0.40% phosphorus is fed, then phytase can be used as a safety factor, but generally will have no observable effect unless the diet actually has less than the formulated amount of phosphorus. The phosphorus content must be below the requirement, generally at least 10% below or 0.36% in this case, to see any phytase effect.

Use 'non-traditional' feedstuffs: In general, as the computer has the ability to select from a larger variety of ingredients, costs will be reduced. Therefore, using 'non-traditional' or 'alternative' feedstuffs, feedstuffs other than maize and soya, have the potential to reduce feed costs. If the formulator wishes to get a specific level of protein, such as 20% and only corn (8% protein) and soybean meal (48% protein) are used, there is only one potential solution and thus, only one mix possible. Because the diet is formulated for many of these constraints, they become subservient to the single mathematical solution and all other nutrients will be fed above the required level.

Broiler producers in the USA reduce costs by about 10% through use of animal by-products alone. Wheat milling products, barley, whole wheat, animal by-products, etc, should all be considered as viable options in formulas where possible, although some of these ingredients require the use of an enzyme to achieve best results. The 'what if' capability of the computer should be used for this purpose before any feedstuffs are actually purchased. All feedstuffs should have an equal cost basis for comparison, which means as delivered to the mill.

Use more purified ingredients: The formulator should start the formulation process with as many choices for the computer as possible, including purified nutrient sources. For example, some companies will put chorine into the premix and then place a constraint on choline. The computer then searches for the cheapest source of choline in the available nutrient matrix. It may add extra of the premix or, if it is constrained, it may add extra soya at relatively high cost. Depending on prices, etc, I have seen as much as US$5.00 per ton saved by adding choline as a purified source. Potential savings could be such that adding new storage capacity may be warranted. In general, as ingredients are added to the diet, total ration cost decreases. Those who are feeding maize-soya have the biggest potential cost savings, while those already feeding three or more energy-protein sources gain the least benefit.

Start with minimal nutrient constraints: Nutrient and ingredient constraints are part of the computerized formulation process, and although the formulator must be careful in making changes, constraints can be replaced after seeing the effects of their adjustment. The formulator should start the process with minimal ingredient constraints. For example, meat-and-bone meal is constrained at 7.5% of the diet based on several sources of information. This is quite a simplistic approach to formulation as it does not even account for the relative proportion of the protein being provided by the product. If meat-and-bone meal comes into the formula at 7.8%, there are no detriments to performance, but there are cost savings.

Chart: Changing dietary levels relative to actual requirements 

Look for 'pressure' on the nutrient matrix: 'Pressure' in the formulation occurs when proposed use of an ingredient or nutrient encounters a constraint. Using the meat-and-bone meal example, there is a constraint at 7.5% of the diet, so if the formula adds 6.23%, then there is no pressure on the formulation matrix. However, if the computer puts in 7.500%, we have pressure on the matrix at this point. Relieving the pressure in some fashion can result in cost savings. This can be done obviously by removing the constraint to see what happens, meat-and-bone meal may go to 25% of the diet which may be unacceptable. Or, one can look for other points of pressure and see what it is that the computer wants' that meat-and-bone meal provides. A very small change in a constraint will save several dollars per ton.

Reduce protein constraints: The NRC protein constraint for a starter broiler ration is 23%, which can be safely reduced by several percent. Probably cost savings begin to accrue at 21% CP with similar growth. It is important to monitor amino acid levels so that no deficiencies occur. Deep reductions may not reduce costs as there would be increased use of purified amino acids, although this varies depending upon ingredient prices.

Add more crystalline AA to the matrix: In pigs, use of threonine or tryptophan can allow for more reduction in protein. Careful addition of threonine with reduced protein constraints, typically below 23%may save several dollars per ton. Always remember to look at next limiting AA as crude protein is reduced.

Look closely at safety margins: A safety margin in formulation seeks to account for dietary differences due to variation in ingredients, mixing, feed segregation, etc. While this makes sense, there is a cost associated with it and the cost increases with increased feed costs. The formulation should at least consider formulating at the requirements to know the cost of the safety factor.