Soybean meal fed to pigs undergoes heat treatment to destroy trypsin inhibitors and other antinutritional factors that impair the digestion of protein and thus reduce performance. However, heat treatment can damage nutrients as well. In particular, the Maillard reaction reduces amino acid digestibility by combining amino acids with sugars to produce biologically unavailable compounds.

An experiment was conducted to determine the digestibility of amino acids in pigs fed soybean meal that had been heat treated in varying ways and for varying times. Conventional soybean meal was divided into four batches. One batch was not heated; one was autoclaved at 125°C for 15 minutes; one was autoclaved at 125°C for 30 minutes; and the last one was oven dried at 125°C for 30 minutes. Ten growing barrows were fed a total of five different diets. The experimental diets contained 40% each of the four different soybean meals being tested. An N-free diet was also formulated and fed to measure the basal endogenous loss of protein and amino acids.

Meat and bone meal (MBM) is a product of the rendering industry composed primarily of the offal and bones of slaughtered livestock, fat from unmarketable animal tissues, unsellable retail meat products, and whole condemned carcasses (excluding hair, blood, hooves, horns, and contents of the gastrointestinal tract).  MBM is traditionally used as an animal protein source in swine diets, but because of its high concentrations of calcium and phosphorus, it can also replace inorganic phosphates in swine diets.

The proportions of soft tissue and bone in different sources of MBM can vary widely. Because mineral digestibility differs in bone and soft tissue, the variation in composition of MBM sources leads to a variation in mineral digestibility values.

An experiment was conducted to 1) determine the apparent (ATTD) and standardized (STTD) total tract digestibility of phosphorus and the ATTD of calcium in 8 different sources of MBM,  2) estimate variation among MBM sources, and 3) develop equations to predict the concentrations of digestible phosphorus and calcium in MBM.

Soybean meal is a rich source of digestible amino acids for pigs. However, soybeans contain antinutritional factors such as antigenic proteins, oligosaccharides, lectins, and trypsin inhibitors that make soybeans and conventional soybean meal unsuitable for feeding to weanling pigs in great quantities. Therefore, animal protein is usually included in starter diets for pigs. Because soy protein is less expensive than the animal protein, strategies to reduce the antinutritional factors in soy products have been explored. Fermentation of soybean meal with bacteria such as Aspergillus oryzae and Lactobacillus subtilis eliminates many antinutritional factors, and studies have shown that fermented soybean meal is well-tolerated by weanling pigs. However, there is a lack of data on the digestibility of energy and amino acids in fermented soybean meal. Two experiments were, therefore, conducted to measure the concentration of DE and ME and the digestibility of amino acids in fermented soybean meal and to compare these values to values obtained in conventional soybean meal and fish meal.

Dried Fermentation Biomass (Ajinomoto Heartland LLC) is a co-product of the commercial production of lysine. Peptone 50 and PEP2+ (TechMix LLC) are co-products of heparin production by the human pharmaceutical industry. The latter two are produced from hydrolyzed pig intestines co-dried with a vegetable protein (Peptone 50) or enzymatically processed vegetable proteins (PEP2+). These co-products are being investigated as possible cost-effective replacements for fish meal in weanling pig diets.

An experiment was performed to measure the apparent and standardized ileal digestibility of CP and amino acids by weanling pigs in Dried Fermentation Biomass, Peptone 50, and PEP2+, respectively, and to compare these values to digestibility values obtained in fish meal.

Corn contains approximately 0.26% phosphorus, but most of this phosphorus is bound to phytic acid, or phytate, and thus is not bioavailable to pigs because they lack the enzyme phytase. Corn-based diets can be supplemented with inorganic phosphorus to help meet pigs' phosphorus needs; however, rising costs of inorganic phosphorus makes this approach increasingly uneconomical. Helping pigs digest more of the phosphorus that naturally occurs in the diet could provide a cost-effective alternative to inorganic phosphorus supplementation while also helping to reduce the environmental burden of excreted phosphorus. An experiment was conducted to determine how adding graded levels of microbial phytase affected the standardized total tract digestibility (STTD) of phosphorus in corn and corn co-products. From these data, regression equations were developed to predict the response to adding different levels of phytase to each ingredient.

Copra and palm kernel co-products are commonly fed to ruminant animals in some parts of the world. However, very limited research has been reported on the use of these ingredients in swine diets. No values are listed in the NRC (1998) for copra expellers, palm kernel expellers, or palm kernel meal.

Rising costs of traditional swine feeds are causing many producers to look for alternative feedstuffs to deliver nutritional value at a lower cost. The corn milling and fermentation industries, and the human food industry, create co-products which can be fed to livestock.  One of these, distillers dried grains with solubles (DDGS), has been found to be suitable for inclusion in swine diets up to 30%. Other co-products have not been as extensively studied. This experiment was performed to measure the apparent (AID) and standardized (SID) ileal digestibility of crude protein and amino acids in corn gluten meal, corn gluten feed, corn germ meal, hominy feed, and bakery meal in growing pigs and to compare these values to the values observed for DDGS and corn.

To determine true digestibility of nutrients, endogenous losses from the digestive tract must be measured. Because consistent values for endogenous losses of fat (ELF) in pigs have yet to be determined, the calculation of fat digestibility has mostly been limited to apparent digestibility.

Endogenous losses of fat may be influenced by the form of fat – extracted or intact – and by the concentration of fiber in the diet. The objective of this experiment was to determine the effect of the form of dietary fat on ileal and total tract digestibility of fat in growing pigs. To do so, it was necessary to measure endogenous losses of fat and to correct for the difference in amounts of dietary fiber in diets containing extracted fat and diets containing intact fat.

Dried blood meal is commonly used as a high-quality protein source in nursery pig diets. Growth studies have indicated that blood meal can be a better protein source than dried skim milk, fish meal, and soy protein concentrate.  However, the growth effects of blood meal vary across studies; this may be due to differences in protein quality.

Limited data exist on digestibility of crude protein and amino acids in blood meal produced from different species and with different drying methods.  Therefore, an experiment was conducted to measure apparent (AID) and standardized (SID) ileal digestibility of crude protein and amino acids in two sources of blood meal.