SWINE NUTRITION
Accurately measure feed efficiency in your operation
By Dr. Kenneth Ferrell, MFA Director of Swine Nutrition

Feed efficiency is the amount of feed it takes to produce a pound of pork. It is one of the best factors to measure if detailed financial records are not available. It directly affects the cost of producing pigs. Feed costs can represent 60 to 70 percent of the production cost of pigs. Several factors can improve feed efficiency; however, the cost of the improvements may not be cost effective.

Feed intake and feed efficiency can vary among commercial farms due to differences in health, social environment, effective temperature, water quality, housing conditions, pen density, barn density, management style, feeding practices, feed quality, sex of pigs, weight in and weight out, and genotype. So it is extremely hard to make comparisons from barn to barn or farm to farm.

Ideally, a good set of records on each group of hogs at each barn would be extremely valuable in obtaining a starting point to monitor feed efficiency. Using estimates can help get a handle on where improvements need to be made.

Beginning pig weights, ending pig weights (pounds), feed delivered and ending pounds of feed are needed to calculate feed efficiency for comparisons between groups.

The following equations can be used to compare different groups with different ending weights and market weights.

Adjusted F/G = observed F/G+(50- entry weight) x .006 + (250- market weight) x .006

The above equation only involves beginning and ending weights of the pigs. If a grain source or energy source or both are used in the diet other than corn or if you feed a pelleted diet versus a meal diet, then adjustments have to be made to the above equation.

The adjustment for energy level is a grain factor - (fat level x 2). The grain factor is 1.0 for corn and 1.02 for milo, and the fat level is the percent fat in the diet. The following equation can be used to make comparisons.

Adjusted F/G = (observed F/G + (50 ­ entry weight) x .006 + (250 ­ mkt weight) x .006)) grain factor ­ (fat level x 2)

As an illustration, a group of pigs with an entry weight of 40 pounds and exit weight of 230 pounds has an adjusted feed efficiency of 3.06 with an observed feed efficiency of 2.7. These pigs were fed a milo supplement diet with 4 percent added fat.

(2.7 + (50-40) x .006 + (250 ­230) x .006 = (2.7 + .06 + .12) = 2.88
1.02 ­ (.04 x 2) =.94
answer = 3.06

If pelleted diets are used versus meal diets, there is a 5 to 7 percent improvement in feed efficiency.

By using these equations, you can make adjustments for changes in weight of pig and type of feed diet. This allows for comparisons from group to group.

Grower-finisher feeds represent the largest feed cost in an operation. To make logical decisions on necessary adjustments, adjusted feed efficiency needs to be used instead of observed feed efficiency.