Rojas, O. J. and H. H. Stein. 2015. Effects of replacing fish, chicken, or poultry by-product meal with fermented soybean meal in diets fed to weanling pigs. Rev. Colomb. Cienc. Pecu. 28:22-41. Link to full text (.pdf)

Pelleting and extrusion are technologies that have been used in livestock feeding to improve nutrient digestibility and feed conversion. Recent research concluded that reduced performance of pigs fed diets containing high concentrations of fiber was ameliorated if the diets were pelleted. Extrusion is also of benefit in high fiber diets, because it may increase the solubility of dietary fiber. It is possible that the benefits of extrusion and pelleting are greater in high fiber diets than in low fiber diets, but this hypothesis has not been investigated. Therefore, an experiment was conducted to determine effects of extrusion and pelleting on energy and nutrient digestibility in diets containing low, medium, or high concentrations of fiber.

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.

Rojas, O. J., Y. Liu, and H. H. Stein. 2014. Concentration of metabolizable energy and digestibility of energy, phosphorus, and amino acids in lemna protein concentrate fed to growing pigs. J. Anim. Sci. 92:5222-5229. Link to full text (.pdf)

Gutierrez, N. A., D. Y. Kil, Y. Liu, J. E. Pettigrew, and H. H. Stein. 2014. Effects of co-products from the corn-ethanol industry on body composition, retention of protein, lipids and energy, and on the net energy of diets fed to growing or finishing pigs. J. Sci. Food Agric. 94:3008-3016. Link to full text (.pdf)

Almeida, F. N., R. C. Sulabo, and H. H. Stein. 2014. Amino acid digestibility and concentration of digestible and metabolizable energy in a threonine biomass product fed to weanling pigs. J. Anim. Sci. 92:4540-4546. Link to full text (.pdf)

Liu, Y., M. Song, T. Maison, and H. H. Stein. 2014. Effects of protein concentration and heat treatment on concentration of digestible and metabolizable energy and on amino acid digestibility in four sources of canola meal fed to growing pigs. J. Anim. Sci. 92:4466-4477. Link to full text (.pdf)

Global production of rice is third in terms of total tonnage after corn and wheat. Rice is grown to produce polished white rice for human consumption. However, harvested rice, called paddy rice or rough rice, needs to be dehulled, which results in production of brown rice. The outer brown bran layer of brown rice, known as rice bran, also needs to be removed before polished white rice is produced. Approximately 20% of the paddy rice is hulls and the bran fraction is 8 to 10%, so only 70% of the paddy rice will become polished rice. 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. 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. Broken rice is high in starch and contains little fat, fiber, or protein.

Both rice bran and broken rice may be fed to pigs, but these ingredients are poorly characterized in terms of nutritional value. An experiment was, therefore, conducted to determine the standardized ileal digestibility (SID) of crude protein and amino acids in broken rice, two sources of full fat rice bran (FFRB), and defatted rice bran (DFRB) fed to growing pigs.

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.