Merriman, L. A. and H. H. Stein. 2016. Particle size of calcium carbonate does not affect apparent and standardized total tract digestibility of calcium, retention of calcium, or growth performance of growing pigs. J. Anim. Sci. 94:3844-3850. Link to full text (.pdf)

She, Y., H. H. Salgado, D. Li, and H. H. Stein. 2016. Effects of high protein canola meal on digestibility of phosphorus and growth performance of weanling pigs. J. Anim. Sci. 94(E-Suppl. 5):457 (Abstr.) Link to abstract (.pdf)

Because of the presence of antinutritional factors, the use of soybean meal in weanling pig diets is limited. Animal protein sources can be used, but their cost is high relative to plant protein sources. Therefore, it is economically advantageous to find high quality plant protein sources that weanling pigs can tolerate.

Soybean meal can be processed in various ways to remove or reduce antinutritional factors. One way is to use an alcohol extraction process to remove water-soluble carbohydrates, followed by heat treatment. This process produces soy protein concentrate. An experiment was conducted to determine effects of feeding a soy protein concentrate product called X-SOY 200 on growth performance and blood parameters in 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.

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.

Boler, D. D., M. F. Overholt, J. E. Lowell, A. C. Dilger, and H. H. Stein. 2015. Effects of pelleting growing-finishing swine diets on growth, carcass, and bacon characteristics. Pages 23-30 in Proc. Midwest Swine Nutr. Conf. Indianapolis, IN, Sep. 10, 2015. Link to full text (.pdf)

It is important to include calcium and phosphorus in the diets in the proper proportions because the excess or deficiency of one mineral may affect the utilization of the other. Calcium requirements in the 2012 NRC are based on a model, which used a 2.15 ratio of total calcium to standardized total tract digestible (STTD) phosphorus. An optimal ratio of STTD calcium to STTD phosphorus has not been reported because not enough data exist on the standardized total tract digestibility of calcium. However, recent studies conducted by the Stein Monogastric Nutrition Lab have determined values for STTD calcium for several calcium sources. With these data, it is possible to determine the requirement for STTD calcium. Therefore, an experiment was conducted to determine the requirement of STTD calcium to maximize growth performance and bone ash in 11 to 25 kg pigs.

Jaworski, N. W., A. Owusu-Asiedu, A. Awati, A. Thomas, and H. H. Stein. 2015. Effect of a 3-strain Bacillus-based direct-fed microbial on growth performance, volatile fatty acid production, carcass characteristics, and gastrointestinal tract weights in growing-finishing pigs fed low or high fiber diets. J. Anim. Sci. 93(Suppl. s3):856 (Abstr.) Link to abstract (.pdf)