For years, animal protein products have seen limited use in swine diets because of cost, or concerns they could serve as vectors for certain swine diseases.

Things have changed. Pork producers currently have an opportunity to reduce feed costs and/or stretch soybean meal supplies by using animal proteins and additional amino acids.

Animal protein products are competitively priced vs. soybean meal because of the recent export ban on shipping animal protein products out of the U.S. Nutrient analyses of meat meal vs. soybean meal are spelled out in Table 1.

Table 1. Nutrient Analyses of Meal Products for Swine Diets
Meat Meal Soybean Meal
(%) (%) (%)
Crude Protein 50.0 44.0 47.0
Crude Fat 8.0 0.5 0.5
Calcium 8.0 0.25 0.25
Total/Av. Phosphorus 4.00/3.60 0.60/0.19 0.65/0.16
Total/Dig. Lysine 2.60/2.34 2.90/2.45 3.04/2.58
Total/Dig. Tryptophan 0.27/0.23 0.60/0.48 0.65/0.52

Processing methods, improved temperature control during processing and overall quality control have improved markedly in the past 20 years, resulting in reported amino acid digestibility of 85 to 92% for the major, limiting amino acids — lysine; threonine; methionine + cystine; and tryptophan in swine diets. Animal protein products are good sources of amino acids, except for tryptophan, and a very good source of calcium and phosphorus.

According to Sparks Commodities, Memphis, TN, about 85% of animal proteins produced in 2001 were used in the feed industry — 43% in poultry, 23% in pet foods, 13% in swine, 10% in ruminants and 11% in feeds for other species. About 15% was exported.

Also, Sparks reported animal protein use in the U.S. was 737.6 million tons in 2001, about 7 lb./market hog.

The current ban on feeding or exporting ruminant animal protein will make this product available for use in swine diets. Estimates are that 75% (2.5 million tons) of animal protein produced in the U.S. is totally or partially derived from ruminant animals and, therefore, cannot be fed to cattle or other ruminant animals. The increased quantities of animal protein will be used as a replacement for almost equal quantities of soybean meal (Tables 2, 3).

Categorizing Animal Proteins

The current inventory of animal protein products has been divided into two categories since the late '90s because of the bovine spongiform encephalopathy (BSE) issue in the United Kingdom. One category contains any amount of ruminant material, commonly referred to as “ruminant animal protein.” The second category is derived from pork materials, commonly referred to as “porcine animal protein.”

The current Food and Drug Administration (FDA) regulations indicate that porcine animal protein can be fed to all species, while ruminant animal protein cannot be fed to ruminant animals, but can be fed to other species.

The reason tryptophan is a limiting amino acid in meat meal and meat and bone meal is due to the presence of collagen. Collagen is found in bone protein, skin, connective tissue, cartilage, and tendons, which contain no tryptophan.

Estimates that are up to 50% of total protein in these products could be from collagen. Therefore, when formulating swine diets, using the current amino acid digestibility coefficients and available phosphorus levels for ruminant- and porcine-derived products, and the appropriate amino acid ratios for the final diet, product usage will be limited to about 5% of the complete diet.

Synthetic Amino Acids

The use of synthetic amino acids over the “standard” 3 lb./ton of L-lysine will stretch soybean meal supplies.

The use of additional L-lysine requires the supplementation of amino acids L-threonine and dl-methionine, which are readily available.

Every dietary lysine level will result in different amounts of supplemental amino acids in the diet when formulating diets with increased levels of L-lysine plus supplemental L-threonine and dl-methionine.

The use of additional synthetic amino acids has the biggest impact on substituting for soybean meal and economics at the highest dietary lysine level, and the lowest impact at the lowest dietary lysine level. The digestible tryptophan minimum restriction prevents the usage of additional synthetic amino acids.

Keep in mind that a grow-finish pig, from 50 lb. to market weight, consumes nearly two-thirds of its feed requirements at the lower dietary lysine levels.

Another alternative that needs to be carefully evaluated is reducing the amount of soybean meal in the diet by up to 2½%. Although the 2½% reduction lowers dietary lysine by approximately 0.07%, research has shown that feeding protein or amino acid deficient diets will result in slightly fatter carcasses, which could affect carcass premium and reduce growth performance.

Animal Protein vs. Soybean Meal

Table 1 provides a comparison of animal protein to soybean meal for a few major nutrients. The amount of animal protein formulated into a typical corn-soybean meal diet will vary slightly depending on the nutrient analysis used.

The 0.66% digestible lysine grow-finish swine diets (44% soybean meal in Table 2 and 47% soybean meal in Table 3) are based on using 50% meat meal.

Prices for 50% porcine meat meal have been up to $100/ton less than 44% soybean meal, and 50% ruminant meat meal was priced up to $150/ton less than 44% soybean meal this past winter.

When adding 5% meat meal to the diet, if the 50% meat meal is the same price as 44% soybean meal (Table 2), the diet cost is reduced about $1/ton. If 50% meat meal is the same price as 47% soybean meal (Table 3), the diet cost is reduced about 60¢/ton.

Table 2. Digestible Lysine Grow-Finish Diets Using 44% Soybean Meal
Ingredient Example Corn-Soybean Meal (lb.) Added 5% Meat Meal (lb.) Substitution (lb.) Added 3.6% Meat Meal + Phytase (lb.) Substitution (lb.)
Corn 1612 1638 + 26 1642 + 31
44% Soybean Meal 331 233 - 98 260 - 71
50% Meat Meal 100 + 100 72 + 72
18½% Dicalcium Phosphate 24 6 -18 - 24
Limestone 15 5 - 10 7 - 8
Phytase-1000 1 + 1

Table 3. Digestible Lysine Grow-Finish Diets Using 47% Soybean Meal
Ingredient Example Corn-Soybean Meal (lb.) Added 5% Meat Meal (lb.) Substitution (lb.) Added 3.75% Meat Meal + Phytase (lb.) Substitution (lb.)
Corn 1630 1650 + 20 1656 + 26
47% Soybean Meal 313 221 - 92 243 - 70
50% Meat Meal 100 + 100 75 + 75
18½% Dicalcium Phosphate 24 6 -18 - 24
Limestone 15 5 - 10 7 - 8
Phytase-1000 1 + 1

Therefore, based on recent ingredient costs, the savings could have reached $8/ton when using 5% meat meal in the grow-finish diet. That savings is achieved by taking the soybean meal price minus meat meal price, times percent usage rate/ton, plus the difference in diet cost when soybean meal and meat meal are equally priced. That equals the diet cost savings we have seen this past winter. For example, $300/ton for 47% soybean meal minus $250/ton for 50% ruminant meat meal times 5% meat meal plus 60¢ (at 5%) = $3.10.

The price relationships between animal protein and soybean meal are very unusual. Historically, animal proteins have been priced slightly higher.

Proper handling and storage facilities are needed to use animal proteins because of the tendency to set up due to the higher fat content and smaller particle size of animal protein vs. soybean meal.

Feed Processing Safeguards

The feed regulations, issued by the FDA on Jan. 26, 2004, affected the use and handling of animal protein through four new regulations:

  • Ruminant blood cannot be fed to ruminants as a protein source;

  • Poultry litter is banned as a feed ingredient for ruminant animals;

  • Plate waste cannot be used as a feed ingredient for ruminants; and

  • To minimize the possibility of cross-contamination, the equipment, facilities and production lines used to make non-ruminant animal feeds containing protein sources, prohibited in ruminant feeds, cannot be used to make feeds for ruminant animals.

Salmonella Concerns

Some producers may wonder if they should be concerned about salmonella contamination when meat meal/meat and bone meal are added to a swine diet. These products should be of no more concern than other ingredients used in swine diets.

Several research projects have detected salmonella contamination of various feed ingredients and in mixed diets. But proper heat treatment during processing of ingredients and/or pelleting of complete diets minimizes the salmonella.

The prevalence of salmonella in ingredients and mixed diets is highly correlated to the cleanliness of equipment, storage areas and trucks. Rodent control and bird proofing of feed and swine facilities are major preventative measures for reducing salmonella contamination.

John Goihl, Shakopee, MN, can be reached by telephone, (952) 445-7001; fax, (952) 445-1911; or e-mail,

Defining Animal Protein Products

American feed control officials differentiate meat meal and meat and bone meal:

  • Both are the “rendered products from mammal tissues, exclusive of any blood, hair, hoof, horn, hide trimmings, manure, stomach and rumen contents, except in such amounts as may occur unavoidably in good processing practices.”

The difference between meat meal and meat and bone meal is in the phosphorus content:

  • Meat and bone meal contains a minimum of 4.0% phosphorus.

  • Meat meal phosphorus level is less than 4%.

For each product, the calcium level shall not exceed the actual level of phosphorus by more than 2.2 times. We typically use 4% phosphorus and 8% calcium for meat meal and 4.4% phosphorus and 9% calcium for meat and bone meal.