After corn and wheat, rice is the third most widely grown cereal grain worldwide. Most rice is processed to produce polished white rice for human consumption, and several co-products result from this processing. First, the outer husk, or hull, of the grain is removed. The dehulled grain, consisting of the bran, germ, and endosperm, is brown rice. To produce white rice, the brown rice is milled further and the bran is removed. Rice bran is high in fiber, and also contains about 15% crude protein and 14 to 20% fat. Rice bran can be fed as full fat rice bran or defatted rice bran. Rice bran is sometimes combined with rice hulls to produce rice mill feed. During milling of the rice, some kernels may get broken and cannot be used for human consumption. These broken kernels are known as broken rice or brewers rice and may also be used in animal feeding.

The phosphorus content of rice is similar to that of corn. Most of the phosphorus in rice is in the bran fraction, and 80-85% of the phosphorus in rice bran is bound to phytate, which limits its digestibility by pigs. Microbial phytase can be used in swine diets to increase the digestibility of phytate-bound phosphorus. However, limited information exists about phosphorus digestibility in rice co-products and how it is affected by microbial phytase. Therefore, an experiment was conducted to determine the apparent (ATTD) and standardized (STTD) total tract digestibility of phosphorus in brown rice, broken rice, full fat rice bran (FFRB), defatted rice bran (DFRB), and rice mill feed fed to growing pigs. A second objective of the experiment was to determine the effect of microbial phytase on phosphorus digestibility in rice co-products.

Distillers dried grains with solubles (DDGS) is a co-product of the ethanol industry and is often used as an economical source of energy and protein in swine diets. Conventional DDGS contains approximately 27% crude protein, 10% fat, 9% acid detergent fiber (ADF), and 25% (NDF). The concentrations of digestible energy (DE) and metabolizable energy (ME) in conventional sources of DDGS are approximately 3,500 and 3,350 kcal/kg, respectively. However, there is significant variation in the way different plants produce DDGS. For example, in recent years ethanol plants have begun extracting oil from DDGS to sell to the biodiesel industry. This results in DDGS with its fat content reduced to approximately 6 to 9%, which may result in lower concentrations of DE and ME.

If pigs are fed diets containing decreased levels of DE and ME relative to conventional DDGS, a reduction in growth performance may result. This would make DDGS a less economical feedstuff. An experiment was conducted to determine the variability of DE and ME in DDGS produced in and around Illinois.

When evaluating the energy content of pig diets, producers and feed companies in the United States usually use the digestible energy (DE) and metabolizable energy (ME) systems. However, these systems do not take into account the heat produced by the animals during digestion, and thus the energy lost by pigs in the process of digesting and metabolizing the feed. Pigs fed diets high in fiber have greater feed intake, larger gastrointestinal tracts, and increased hindgut fermentation relative to pigs fed diets containing less fiber. Therefore, they might be expected to have greater heat production as well. As a result, the DE and ME systems may overestimate the energy value of fibrous feed ingredients. Net energy (NE) takes heat production into account, and thus may be a more accurate estimate of the energy available to the pig.

An experiment was conducted to test the hypothesis that increasing dietary fiber in diets fed to growing pigs will increase heat production and decrease net energy values.

Lysine is the first limiting amino acid in swine diets based on corn and soybean meal. Lysine requirements for pigs are affected by growth rate and lean deposition rate, which in turn are affected by sex, genetics, age, and other factors. An experiment was conducted to determine the requirement for standardized ileal digestible (SID) lysine in 25 to 50 kg growing gilts.

The presence of phytate in swine diets reduces the digestibility of calcium because phytate is able to bind calcium from organic sources and some inorganic sources, making it inaccessible to the pig. Microbial phytase breaks down phytate and increases the availability of calcium. An experiment was conducted to test the hypothesis that inclusion of microbial phytase increases the apparent (ATTD) and standardized (STTD) total tract digestibility of calcium in fish meal in diets containing phytate from corn and corn germ.

Besides phytate, corn and corn germ also add fiber and fat to diets, so it is important to know how fiber and fat affect calcium digestibility. Therefore, a second experiment was conducted to test the hypothesis that the values of ATTD and STTD of calcium obtained from cornstarch and corn based diets may differ, and to determine the effect of dietary fiber and fat on the ATTD and STTD of calcium in fish meal.

Recently, the Food and Drug Administration announced that the number of antibiotic growth promoters that are available to be used by pigs will be reduced to reduce the risk of transferring antibiotic resistance from animals to humans. Only antibiotics that are not used in human medicine may be used as antibiotic growth promoters by animals in the future. To accommodate this change, it may be necessary to re-evaluate the use of antibiotic growth promoters in diets fed to pigs. It is possible that antibiotic growth promoters may be eliminated from swine diets if the complexity of the diets is increased. To test this hypothesis, an experiment was conducted to determine the effects of using an antibiotic growth promoter in diets formulated to vary in complexity.

The carob tree (Ceratonia siliqua) is an evergreen native to the Mediterranean area. Its fruit, technically a legume, consists of leathery brown pods that contain hard brown seeds in a sweet pulp. The pods can be crushed, with or without the seeds, to produce a meal that is fed to animals. Because carob pod meal contains 40-45% sugars, it promotes feed intake and adds energy to the diet. Carob pods also contain tannins. As inclusion rates of carob pod meal increase, the tannins can inhibit nutrient digestibility, which limits carob inclusion in swine diets. However, at lower inclusion rates, carob pod meal can reduce the incidence of diarrhea in weanling pigs due to the tannins' effect on the intestinal mucosa.

Caromic 105 is a deseeded, toasted, micronized carob pod meal product. An experiment was conducted to determine the effect of Caromic 105 on growth performance of weanling pigs.

Soybean meal is the most common source of protein in swine diets in the United States. However, conventional soybean meal contains antinutritional factors such as antigenic proteins, oligosaccharides, lectins, and trypsin inhibitors that limit its use in diets fed to weanling pigs. Methods of processing soybean meal to remove antinutritional factors have been developed. These include enzyme treatment, fermentation, and the removal of soluble carbohydrates.

Like soybean meal, rapeseed products are usually not fed to weanling pigs due to the presence of glucosinolates and relatively high concentrations of fiber in these products. Previous research has shown that fermentation of soybean meal can reduce antinutritional factors and fiber concentrations. It is possible that fermentation can make 00-rapeseed meals and 00-rapeseed expellers suitable for feeding to weanling pigs, but no research has been conducted to confirm this hypothesis. An experiment was conducted to determine the standardized ileal digestibility (SID) by weanling pigs of crude protein and amino acids in four sources of processed soybean products, conventional soybean meal, conventional 00-rapeseed expellers, and in a fermented mixture of co-products including 00-rapeseed expellers, wheat bran, potato peel, and soy molasses.

Grinding of feedstuffs to small particle sizes is a low-cost way to increase their energy and nutrient digestibility. Currently, nutritionists recommend feeding corn ground to an average particle size of 650 to 700 µm. However, it may be advisable to formulate diets containing corn ground to smaller particle sizes due to the greater metabolizable energy (ME) values of these diets. A previous experiment conducted by Rojas and Stein at the University of Illinois demonstrated that when diets are formulated to contain the same amount of metabolizable energy, feeding diets containing corn ground to different sizes to weanling pigs did not have a negative effect on growth performance.

An experiment was conducted to test the hypothesis that when diets are not adjusted to contain equivalent amounts of metabolizable energy, weanling pigs fed diets containing corn ground to smaller particles sizes will have an improved gain to feed ratio relative to pigs fed corn containing corn ground to larger particle sizes.