Efficiency equals economic returns. You've heard that or a similar statement many times before.

Economics, feed efficiency and reduced nutrient excretion all fall within the same economic arena. "Anything we can do in one area helps all the others," says Jerry Shurson, extension swine specialist, University of Minnesota.

To help producers see all the options as they try to make an operation more efficient, both Shurson and Lee Johnston, West Central Experiment Station, Morris, MN, use a feeding program "decision tree" as an illustration (see Figure 1).

Johnston says the decision tree helps organize broad categories of high-impact factors that contribute to high feed costs/cwt. of pork produced. Feed cost/cwt. produced is comprised of whole herd feed/gain and feed cost/ton. Under each of the broad categories is a series of additional, interrelated factors.

"Effective nutritional consultants focus on the broad categories first to determine if performance in that area meets expectations," Johnston explains. "If expectations are met, the next category is evaluated. If expectations are not met, then one must travel down the tree to determine the source of poor performance."

The key to improving feed conversion (F/G), for example, is to start by focusing on the obvious, high-impact factors that can be changed with the least amount of effort. Then move on to the factors that get progressively more difficult or costly to correct, he says.

Shurson says the factors listed under the Whole Herd Feed/Gain "branch" of the decision tree tell a lot about how a farm is doing, but there is more to the big picture than just those areas. "Probably the ultimate measure would be return/sq. ft. or return/pig space when it comes to capturing nutritional value of some diets," he explains. "I think the decision tree helps producers realize when it comes to evaluating feeding programs, it is really a whole combination of things that have to be looked at sequentially."

By doing a better job of estimating nutrient requirements for specific farms, producers can reduce feed cost/lb. of gain. Specific data to use in estimating those requirements include: feed intake, lean gain/day (in the grow-finish stage), gestation weight gain, lactation performance measures (such as feed intake and litter weaning weight) and weight gain and feed intake in the nursery.

Feed Quality Control Shurson says quality control of feed manufacturing can either support or interfere with providing the desired diet composition to pigs. Formulation accuracy, correct particle size and mixing time are all crucial components of a feed quality control program. Having accurate scales (and making sure they get used) is another key.

Records should be kept on all production areas, including feed use. Johnston says at the very least, producers should record the weight of all feed deliveries to each phase of production, and the weight of all live pigs and sows leaving the unit.

Correct Ingredient Use Another key is to use every ingredient correctly. Shurson has seen a number of diets, particularly nursery diets, using both zinc oxide and copper sulfate.

"First of all, zinc oxide at high levels fits best within the first couple of weeks after weaning," Shurson explains. "We shouldn't feed it longer than that because of potential toxicity problems. A lot of producers are continuing to use copper sulfate with high levels of zinc. There is no reason to do that because there is no additive effect of having both in the diet."

Shurson says some producers are keeping copper sulfate in diets all the way to the finisher. "Copper sulfate acts like an antimicrobial and can have negative effects on solids' breakdown in anaerobic pits," he says.

Mycotoxin tests should be performed regularly, Johnston says. Midwest producers should be testing for vomitoxin, which reduces feed intake, and zearalenone, which causes high embryo mortality at high levels. Producers in the South should test for aflatoxins, which compromise pigs' immune systems.

Management Production System Johnston says alterations in management practices that increase comfort and improve health of growing pigs, finishing pigs and sows will likely improve efficiency of converting feed to pork.

Some areas, such as genetics, health, temperature/ventilation, space, feeder space, added fat, mixing/moving and growth promotants, repeat on various branches of the tree.

Johnston suggests implementing all-in, all-out pig flow to improve health status and allow easier adoption of phase feeding programs. He also says a rigid biosecurity program must be maintained. "Healthy pigs that are free of parasites are more efficient than pigs with lower health status," he says.

Keeping growing pigs and sows cool during hot weather helps reduce the amount of feed required and helps increase performance. However, Johnston says the cost of keeping animals cool needs to make economic sense in relation to the feed cost savings.

Johnston says pigs should not be overcrowded if producers are seeking to improve feed conversion. "Producers still need to figure out if this is the best economic strategy when considering the relative costs of feed and facilities," he says.

Fat and fiber levels should be adjusted based on environmental temperature. According to Johnston, the level of fat and fiber in the diet has a profound effect on the efficiency of feed conversion for growing-finishing pigs. His rule of thumb - for every 1% increase in dietary fat there is a 2% improvement in feed efficiency. "It is important to be aware, however, that fat supplementation may improve feed efficiency without improving economic returns," he cautions.

Increasing dietary fiber negatively influences feed efficiency. Increasing fiber levels is more detrimental in young pigs compared to older pigs. "To achieve maximum feed efficiency, remove fibrous feedstuffs from nursery and growing pig diets," Johnston suggests.

He says it is also important to minimize social stresses associated with mixing pigs.

Moving to the feed wastage branch, Johnston recognizes wastage occurs on every farm. Wasted feed can have a big economic impact. "A general thumb rule in the grow-finish phase is that if any feed is observed on the floor, this equates to at least 10% feed wastage," he says.

He suggests checking and adjusting feeders between two and three times a week. Feeder settings should be adjusted so there is slightly less than 50% of the feed trough covered. This setting keeps feed fresher in the trough, minimizes spoilage, and reduces feed build-up. Feeders should adjust easily so workers will make the adjustments.

Feeders should be designed to match the age and stage of the pigs using them. Pigs and sows should be able to consume feed comfortably without removing their heads from their feeders.

Worn out feeders should be replaced, Johnston says. Leaky bins, bin boots and augers should also be repaired or replaced. Prevent pigs from soiling the feed trough with feces or urine. Implement rodent and bird control programs to prevent contaminated feed.

Ingredient Cost "Ingredient cost contributes the majority of the total feed cost/ton, followed by the manufacturing cost, delivery cost and profit margin," Shurson says. He points out corn (primary energy source), soybean meal (primary amino acid source) and dicalcium phosphate (primary phosphorus source) are the three greatest cost contributors to ingredient cost of the diet. "Special considerations must be given toward meeting nutrient consistency and quality standards, while minimizing the purchase price of these nutrient sources," he says. Forward contracting corn and soybean meal is a good way of controlling diet cost/ton.

There should be a reason for adding every ingredient to a diet. "The ingredient has to provide something," Shurson says. "If you take the time to look at revenue, or return/pig space, you can account for effects of better quality nutrition on growth rate, pig flow and carcass benefits. You need to make sure the ingredients make economic sense, while not undervaluing proven benefits."

Shurson says the same rule applies to feed additives. "You should have confidence that the additive will return more money than it costs to put in," he says.

According to Shurson, on-farm feed manufacturing costs, including depreciation, interest, labor, utilities and analytical costs, range from $5 to $50/ton, depending on milling capacity and tonnage required/week.

Delivery cost from commercial mills typically costs $.90 to $1.20/loaded mile or $4/ton in a loaded truck. "Profit margins vary considerably among commercial feed products, with complete pelleted starter feed generally having the highest margin over costs, and finishing feeds having the lowest margins," Shurson says.

Making Good Decisions Both Shurson and Johnston emphasize the importance of consulting with an experienced nutritionist when evaluating swine diets. "Periodically reevaluate formulations to ensure a continued good fit between diet formulations and the performance potential of the pigs," Johnston says. "However, one should resist the temptation to immediately tinker with re-formulation of diets when pig performance does not meet expectations."

Johnston says the goal is to "walk" the nutrients off the farm.