Wheat middlings and red dog are coproducts of the wheat milling process that are used as a source of energy and protein in animal feed. Wheat middlings are granular particles of the wheat endosperm, bran and germ. Red dog consists mainly of the aleurone layer that lies between the bran and the endosperm, along with small particles of bran, germ, and flour. It is often used in extrusion mixtures and as a pellet binder.

The digestibility of crude protein and amino acids in wheat coproducts produced in China has been reported, but there is limited information about the nutritional value of wheat middlings and red dog produced in the United States. In addition, because wheat coproducts vary in terms of the conditions under which they are produced, their nutritional value may vary as well. Therefore, the objective of this experiment was to determine the concentration and digestibility of crude protein and amino acids in ten sources of wheat middlings and in one source of red dog.

Zinc oxide, when added to weanling pig diets in pharmacological quantities of up to 2,500 mg/kg, can help prevent diarrhea during the post-weaning period. However, adding large quantities of zinc to diets has drawbacks. Zinc can interfere with calcium digestibility because it competes for the same transport pathway in cells lining the small intestine. Zinc may also reduce calcium digestibility by forming complexes with calcium and phytate.

The standardized total tract digestibility (STTD) of calcium in various ingredients has only recently been determined, and possible interactions between zinc and phytase on the STTD of calcium have not yet been reported. Therefore, an experiment was conducted to determine the effects of addition of zinc oxide and microbial phytase on STTD of calcium in diets fed to weanling pigs.

Milk co-products are used in pig diets to provide lactose and, in some cases, high quality protein. In addition, milk co-products also provide calcium to the diets. However, this calcium can potentially bind to the phytate contained in the plant ingredients in the diets, which would reduce its digestibility.

Soy protein concentrate is produced by aqueous ethanol extraction of water-soluble carbohydrates from soybean meal, followed by heat treatment. The ethanol extraction process removes soluble carbohydrates, leaving a product that contains at least 65% crude protein (dry matter basis). Because soy protein concentrate contains reduced levels of oligosaccharides, trypsin inhibitors, and lectins compared with conventional soybean meal, it can be used in diets for weanling pigs.

Rice bran is the brown outer layer of brown rice, which is removed from brown rice to produce white polished rice for human consumption. Rice bran may be full fat, containing 14 to 25% fat, or defatted, which reduces the concentration of fat to less than 5%.

Rice bran has a high concentration of non-starch polysaccharides (NSP), primarily arabinoxylan and cellulose. NSPs decrease nutrient digestibility and thus limit the inclusion of rice bran in weanling pig diets. Recent data from our laboratory indicate that adding exogenous xylanase to diets containing full fat rice bran (FFRB) or defatted rice bran (DFRB) increases the concentrations of digestible and metabolizable energy. The objective of this experiment was to determine the effects of increased inclusion levels of FFRB or DFRB to diets without or with exogenous xylanase on growth performance.

Increasing the inclusion of dietary fiber in nursery pig diets may stimulate beneficial gut microbiota and reduce post-weaning diarrhea. However, the digestibility of nutrients and energy is decreased in high fiber diets. Nursery pigs fed diets high in fiber have been shown to have reduced ADFI and G:F.

Bacillus-based direct-fed microbials (DFM) secrete a large amount and a wide variety of fiber degrading enzymes. It is thought that feeding DFM may offset some of the negative effects of  a high fiber diet. Therefore, an experiment was conducted to test the hypothesis that addition of a Bacillus-based DFM will increase fermentation of dietary fiber and improve growth performance when fed to nursery pigs.

Soybean meal is the main protein source used in diets for pigs in the United States, as well as most countries of the world, due to the high quality of the protein it provides. However, soybean meal also contains antinutritional factors that limit its use in weanling pig diets. Pigs do not secrete the enzyme needed for the hydrolysis of raffinose and stachyose, α-galactosidase, in the small intestine. Therefore, these oligosaccharides are not enzymatically digested, but are instead fermented in the small and large intestines. This results in decreased growth performance and increased incidence of diarrhea when fed to weanling pigs.

Oligosaccharides can be removed from soybean meal using an alcohol extraction process, creating soy protein concentrate. Soy protein concentrate has greater digestibility of most amino acids and greater concentrations of digestible energy (DE) and metabolizable energy (ME) than soybean meal. A new source of soy protein concentrate called Nutrivance (Midwest Ag Enterprises Inc., Marshall, MN) has recently been introduced, which is produced using a process combining non-alcohol extraction and enzymatic treatment of soybean meal. The nutritional value of soy protein concentrate produced using this method has not been determined. Therefore, an experiment was conducted to determine the concentrations of DE and ME in soy protein concentrate and to compare these values to DE and ME in soybean meal.

Soybean meal is a high quality source of protein in diets fed to pigs. However, soybean meal contains anti-nutritional factors such as trypsin inhibitors and oligosaccharides, which decrease nutrient availability and limit the amount of soybean meal that can be fed in weanling pig diets.

Soy protein concentrate is produced by processing soybean meal to remove some nonprotein components, including the soluble carbohydrates. This leaves soy protein concentrate with a greater concentration of crude protein and amino acids than soybean meal. The presence of oligosaccharides in soybean meal has been shown to reduce the tolerance of young pigs to conventional soybean meal, and therefore, animal proteins rather than soybean meal is often used in diets for young pigs. However, if the oligosaccharides and other antinutritional factors can be removed from soybean meal, it is possible to use soybean meal in diets for young pigs instead of animal proteins.

Typically, an alcohol extraction process has been used to remove soluble carbohydrates from soybean meal to create soy protein concentrate. However, a new source of soy protein concentrate called Nutrivance (Midwest Ag Enterprises Inc., Marshall, MN) has recently been introduced. Nutrivance is produced using a process combining non-alcohol extraction and enzymatic treatment of soybean meal. The nutritional value of soy protein concentrate produced using this method has not been determined. Therefore, an experiment was conducted to determine the digestibility of amino acids in this new source of soy protein concentrate.