González-Vega, J. C., C. L. Walk, and H. H. Stein. 2016. Requirements for digestible Ca by growing pigs. J. Anim. Sci. 94(Suppl. 2):101 (Abstr.) Link to abstract (.pdf)

Jaworski, N. W., M. C. Walsh, and H. H. Stein. 2016. Effects of fiber, a direct-fed microbial, and feeding duration on ileal and total tract digestibility of energy and nutrients by pigs. J. Anim. Sci. 94(Suppl. 2):73-74 (Abstr.) Link to abstract (.pdf)

An excess of calcium in swine diets may increase excretion of phosphorus due to formation of Ca-P complexes. Therefore, when formulating diets for pigs, it is important to consider the ratio of calcium to phosphorus. The proper ratio should ensure that both minerals are maximally utilized in the bodies of the pigs.

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.

Stein, H. H., G. A. Casas, J. J. Abelilla, Y. Liu, and R. C. Sulabo. 2015. Nutritional value of high fiber co-products from the copra, palm kernel, and rice industries in diets fed to pigs. J. Anim. Sci. Biotechnol. 6:56. Link to full text (.pdf)

Rojas, O. J. and H. H. Stein. 2015. Use of feed technology to improve the nutritional value of feed ingredients. Page 23 in Advances in Animal Nutrition in Australia, Armidale, New South Wales, Australia, October 26-28, 2015. (Abstr.) Link to abstract (.pdf)

Most swine diets must be supplemented with calcium because most plant ingredients commonly used in diets for pigs contain relatively little calcium. One way to add calcium is to include inorganic sources such as dicalcium phosphate or calcium carbonate; however, animal ingredients such as meat byproduct meals can also be used. These ingredients, often used as a protein source, are also a good source of calcium. To our knowledge, values for apparent (ATTD) and standardized (STTD) total tract digestibility of calcium in animal sources have not been reported. Therefore, an experiment was conducted to determine the ATTD and STTD of calcium in four calcium sources of animal origin.

The secondary objective of the study was to test the hypothesis that the addition of microbial phytase to diets containing calcium sources of animal origin would increase the digestibility of calcium. Although animal sources do not contain phytate, swine diets are composed primarily of plant ingredients, and the phytate in those ingredients might form complexes with the calcium in the animal sources.

Li, Z., X. Wang, P. Guo, L. Liu, X. Piao, H. H. Stein, D. Li, and C. Lai. 2015. Prediction of digestible and metabolisable energy in soybean meals produced from soybeans of different origins fed to growing pigs. Arch. Anim. Nutr. 69:473-486. Link to full text (.pdf)

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.