When cost or performance in the nursery or finisher misses targets, a systematic audit can help identify the reasons why. The nutrition audit consists of a preliminary analysis, an on-site visit and an action plan.

Preliminary Analysis

We begin with collecting background data for review before visiting the production system and feedmill (Table 1). This data is used for a preliminary analysis (Table 2) and to guide more detailed exploration during the on-site visit. Areas examined include diet formulation and ingredient cost, feed processing, on-farm feed management and production parameters.

Performance Review

Nutrition areas directly linked to cost and profitability — average daily gain (ADG), average daily feed intake (ADFI), feed efficiency and feed cost per pound of gain — should receive the most focus. Mortality rate, initial weights and final weights also should be reviewed. If data is available in electronic format, trend lines and long-term performance levels can be assessed.

Performance values should be adjusted for known causes of variation. This permits more accurate comparisons for different producers.

For example, grow-finish feed efficiency is adjusted for “in” weight (entry wt.) and “out” weight (market wt.), dietary energy level and diet form using baseline targets (Table 3). These values should be used as upper limits for the feed efficiency targets. If values are not acceptable after adjustment, review other factors such as diet formulation, feeder adjustment or feed particle size.

The ADG values must be viewed with an understanding of the available space in the system. A big question is whether improved ADG would yield more profit. In essence, are pigs achieving optimal market weight for the available finishing space? Carcass grade and yield sheets from packers help in this assessment.

However, interpret market weights with caution. Some producers sell pigs light despite having the finishing capacity to feed to heavier weights.

The question of available space may change seasonally and thus drive diet formulations to be different. For example, because ADG is reduced in summer, the value of higher energy diets or technologies such as Paylean to drive ADG increases in summer.

Diet Review

The next step in the preliminary analysis is to review diet formulation and ingredient prices simultaneously, to ensure they mesh. This review must include a visit to the production system to look for bottlenecks and determine whether to change diets to meet production, environmental or personal goals, rather than simply meeting the cost of production goals.

The reasons to formulate diets for goals other than minimum cost of production include:

  • Lack of quality facilities or management may require more complex nursery diets;

  • Use of high-energy diets to boost ADG and net profit;

  • Altering the last finisher diet to minimize impact on pork fat quality; and

  • Formulating diets to minimize phosphorus and nitrogen output for environmental reasons, even though cost may be increased.



While review of all essential nutrients is important, most critical are dietary energy, amino acids and phosphorus. All diets also are reviewed for the level of vitamins and minerals and appropriate feed additives.

Nursery Diets

Weaning age and number of dietary phases are critical. The quantity of plasma, lactose, other specialty ingredients and soybean meal are key ingredients. With pigs weaned under 21 days of age, a relatively high plasma level (4 to 7%) in the diet immediately after weaning will boost feed intake. The level must be reduced rapidly due to the high cost.

The goal with soybean meal is the opposite. Feed low levels in the first diet after weaning and increase rapidly with each new diet phase.

Other specialty protein sources such as fish meal and blood meal are used in the diet right after weaning to enhance feed intake. Because lactose is the preferred carbohydrate source immediately after weaning, relatively high levels should be included in the diet. The lactose level should be reduced rapidly because it is expensive and its benefit declines rapidly after weaning.

The overall goal in the nursery is to have pigs eating a grain-soybean meal diet by the time they reach 25 lb.

Grow-Finish Diets

Energy and amino acid levels are the main factors to review in grow-finish diets. Cost, availability and impact on feed handling dictate use of different energy sources (grain, fat or byproducts). Because feed intake is usually limited in commercial production, diets for most modern genetics must be formulated on a lysine:energy ratio.

We review the lysine-to-energy ratios for each diet and compare them to projected requirements. The difficulty with grow-finish diets is determining those requirements. If we have lean deposition curves based on ultrasound measurements or from field experiments, we use that information to review the lysine-to-energy ratios.

If this data is not available, we use fat-free lean index (FFLI) from the kill sheets to estimate the lysine requirements (Kansas State University Swine Nutrition Guide). Other amino acid levels in the diets are compared as a ratio to lysine to ensure they are not first limiting before lysine.

In recent years, the level of nutrients leaving the production system, mainly phosphorus and nitrogen, has gained importance. Salt and trace minerals such as zinc and copper also can be a concern.

To limit nutrient excretion, ensure that diets are properly formulated by use of split-sex feeding and phase feeding. Review use of synthetic amino acids and phytase. Use of lean, efficient genetics, proper feeder adjustment and correct grain particle size to improve digestibility all help to limit nutrient excretion.

Ingredient Price Review

In reviewing feed ingredients, consider nutrient content, variability, effect on diet palatability, carcass and meat quality, storage, handling, availability, cost and contamination with compounds such as mycotoxins.

Strict control of ingredient costs is essential to controlling feed costs. The ingredients with the greatest opportunity to reduce costs vary with the production system. Feed budgets and diet formulas are used to quantify the use of each ingredient.

A two-dimensional graph illustrates opportunities for cost savings (Figure 1). The percentage of feed cost contributed by ingredients is depicted along the horizontal axis. The opportunity margin is defined as the relative ability to reduce purchase price and is depicted along the vertical axis. The area of each box represents the opportunity for improved profit for each feed component.

As expected, corn and soybean meal comprise the largest percent of feed cost. However, the margin from lowering the corn or soybean meal price is small, at 10¢/bu. of corn or $10/ton of soybean meal.

Still, the large usage of these ingredients means that a small percentage change in price leads to relatively large opportunities for improved profit. Other energy and protein sources can be substituted for corn and soybean meal in this graph, depending on price and manufacturing situations.

Other opportunities include starter diets fed to pigs under 15 lb., vitamin premix and, to a lesser extent, specialty nursery diet ingredients such as whey, fish meal or blood meal where fairly large differences in pricing exist.

Another big area of opportunity is the phosphorus source, where price depends on efficient transportation, purchasing and quantity discounts.

Feed Processing, Delivery Costs

Feed manufacturing costs can have a major impact on feed costs. In one study, there was a range of $11.85/ton between the highest and lowest cost farms. Toll milling charges for feed manufacturing (grind, mix and delivery) often range from $12-to-$18/ton for a non-pelleted diet.

A rule of thumb is every $3 change in feed manufacturing and delivery cost results in a difference in feed cost of about $1.10/pig.

The delivery cost per mile increases linearly as the truck size increases from 6 to 24 tons; however, the delivery cost per ton decreases as truck size increases (Table 4). When reviewing feed budgets and weight breaks, it is important to consider whether changes would allow for greater efficiencies and lower cost of delivery.

For example, could the standard budget be increased or decreased for a diet to more closely match deliveries? Another example would be having the mill automatically switch to the next diet when less than 50% of a delivery quantity is required to fill out the budget.

Delivering full semi-loads instead of 6- or 12-ton loads can reduce feed cost/pig by $0.49 to $1.49/pig using the example in Table 4.

On-Site Visits

The preliminary analysis of the performance data, diets and ingredients guide the strategy for the on-site visit. Three areas to focus on during the visit include: the feedmill, walk-through of facilities, and clarification of goals and identification of problems with owners, managers and front-line employees.

Feedmill Visit

Because feed manufacturing and delivery is such an integral part of the nutrition program, the feedmill visit is a major focus of the nutrition audit. Grain particle size or ability of the mill to handle multiple diets directly impacts pig performance. By lowering costs at the mill, savings can be passed on to the producer.

The primary focus in the mill review is on delivery of high-quality feed to the farm in the most cost-effective manner.

The mill audit includes a review of individual ingredient costs and quality; grinding, weighing and mixing processes; feed delivery from the mill to bins; potential concerns of mill personnel; and areas where the farm and mill can work together to improve efficiency.

Particle size is one item to review. Because grain particle size impacts feed efficiency, ground grain samples need to be routinely tested. For every 100-micron decrease in average particle size, feed efficiency improves by 1.2%, resulting in a 40¢ to 50¢ improvement in feed cost per pig. Reducing particle size improves energy utilization and feed efficiency.

But particle size can also be too fine, especially for diets in meal form. Fine particle size can cause problems with flow ability of the feed and will limit fat additions to the diet. Although most producers understand its importance, particle size is a problem in many feeding programs. Without continual monitoring, particle size is difficult to maintain in the optimum range of 600 to 800 microns. Regular monitoring must be done in the mill.

Farm Visit

The on-farm nutrition audit provides valuable input on the application of the nutrition program. The program can be well conceived, but still fail if not applied correctly on the farm.

In the nursery, we ask two main questions. First, are pigs starting on feed and water promptly after weaning and transitioning smoothly between diets? Second, are feeders adjusted correctly?

Ventilation and sanitation are also reviewed. Also, look for digestive abnormalities such as loose stools or diarrhea.

Feeder adjustment and general pig management are reviewed in the finishing barns. Feed waste from poor feeder adjustment is a problem in most nursery and grow-finish barns. Improvements in feed efficiency from the reduction in feed wastage directly reduce cost per pound of gain and cost per pig.

For example, feed cost is lowered by over $1/pig in the finisher and 40¢/pig in the nursery by reducing feed efficiency by 0.1. Feed efficiency improvements of 0.1 to 0.2 (i.e.: 3.0 to 2.9 or 3.0 to 2.8) have been accomplished frequently in the field by improving feeder adjustments. Improper adjustment is often the result of poor communication to barn personnel. Posting laminated pictures in all grow-finish and nursery buildings has been an effective tool to communicate proper feeder adjustment. The pictures serve as a constant motivational reminder to help reduce feed waste.

We also review the feed handling system in nurseries and finishers. The goal in bin management is to always have high-quality feed available for every pig in the barn. Maintain quality of feed delivered by reducing moisture buildup or bridging of feed in the bins.

Don't run bins empty for extended periods of time, leaving pigs without feed. Consistent availability of feed is vital to reducing ulcer and ileitis problems in grow-finish.

The size of bins and number of pigs served by a feed line are reviewed during the farm visit to ensure that diets are being budgeted and delivered in an efficient manner.

During a one-time walk-through of a barn, it is difficult to get an accurate picture of pig growth and health. Visual monitoring of pigs for normal growth, comfort and health needs to be conducted daily. Nutritional problems are often first spotted by the critical eye of an excellent stockperson who communicates problems to the swine nutritionist or feed manufacturer for resolution.

Before and after the on-farm audit, a meeting should be held with the owner or production system manager to review production goals and learn of nutritional program problems.

Follow-up Steps for Change

Provide a written report within two weeks of the farm visit. Timeliness is important to reporting and documenting all the areas of opportunity as thoroughly as possible. Economic justification for recommended changes should be included. Provide an action or priority list with the report to briefly identify areas to change and those responsible.

Ideally, a conference call or meeting should be scheduled 4-6 weeks after the written report to assess progress.

Six Key Audit Components

Swine nutrition audits should encompass these six areas:

  1. A clear understanding of the goals of the production system;

  2. A review of background information on current performance levels, diets and feed ingredients, processing and delivery prices;

  3. A review of the feed mill capabilities;

  4. A visual assessment of the application of the nutrition program in the production system;

  5. A complete written report summarizing findings of the audit; and

  6. Assessment of progress. Nutrition audits can be enjoyable, educational and rewarding for the production system and the auditor.



Table 1. Required Background Information

___ Copy of all diet formulations
___ List of all ingredient prices
___ Current feed budget with weight breaks
___ Feed processing and delivery costs
___ Minimum of 10 nursery closeouts
___ Minimum of 10 finisher closeouts
___ FFLI (Fat-Free Lean Index) from kill sheets

Table 2. Checklist for Swine Nutrition Audits

Name: _____
Address: _____
City, State, Zip: _____
Phone: _____ Fax: _____

Pig Performance
___ Are performance levels appropriate?
Diet Formulation
___ Nursery (Correct complexity)
___ Correct number of phases
___ Grow-finish (based on FFLI)*
___ Correct number of G-F phases
___ Lactation-Matched to wean wt.
___ Gestation
Ingredient Cost and Quality
___ Grain
___ Soybean meal, other protein sources
___ Phosphorus
___ Added fat (level and economics) Vitamins and trace minerals, etc.
___ Check vitamin premix age (mix date)
___ Cost
___ Levels
Additives, antibiotics, etc.
___ Are they all necessary?
___ Cost
___ Complete starter diets
Feed Processing
___ Ingredient sources and purchasing
___ Grinding (particle size)
___ Weighing (scales checked?)
___ Mixing efficiency tested?
___ Cost of processing
Delivery from Mill
___ Proper budgeting and delivery
___ Cost and efficiency
Feed Usage on Farm
Feed efficiency
___ Genetic capability (FFLI)
___ Feeders (quality of feeders) Feeder adjustment
___ Are they adjusted correctly?
___ Do they know the proper adjustment?
Environmental Impact (P** and N** control)
___ Diets not over-formulated
___ Proper use of synthetic amino acids
___ Low phosphorus techniques
___ Correct particle size (digestibility)

*FFLI=Fat-Free Lean Index;
**P=phosphorus; N=Nitrogen

Table 3. Interference Levels for Feed Efficiency for Grow-Finish Pigs Consuming Corn-Soybean Meal Based Diets
Meal diets Pelleted diets
Entry wt., lb. Market wt., lb. 0% fat 5% fat 0% fat 5% fat
40 240 2.88 2.59 2.71 2.44
40 250 2.94 2.65 2.76 2.49
40 260 3.00 2.70 2.82 2.54
50 240 2.94 2.65 2.76 2.49
50 250 3.00 2.70 2.82 2.54
50 260 3.06 2.75 2.88 2.59
60 240 3.00 2.70 2.82 2.54
60 250 3.06 2.75 2.88 2.59
60 260 3.12 2.81 2.93 2.64


Table 4. Influence of Feed Truck Size on Delivery Costs
Capacity of truck, tons
Delivery costs 6 12 18 24
Cost/mile, $ $ 1.07 $ 1.14 $ 1.18 $ 1.29
Cost/ton/mile, $/ton $ 0.178 $ 0.095 $ 0.066 $ 0.054
Cost for 1,000 head, $a $2,136 $1,140 $792 $648
Cost/pig, $a $ 2.14 $ 1.14 $ 0.79 $ 0.65
aAssumes a delivery 20 miles from the feedmill (40 miles round trip).