Walk

Requirement for digestible calcium by 25 to 50 kg pigs at different dietary concentrations of phosphorus as indicated by growth performance, bone ash concentration, and calcium and phosphorus balances

González-Vega, J. C., C. L. Walk, M. R. Murphy, and H. H. Stein. 2016. Requirement for digestible calcium by 25 to 50 kg pigs at different dietary concentrations of phosphorus as indicated by growth performance, bone ash concentration, and calcium and phosphorus balances. J. Anim. Sci. 94:5272-5285. Link to abstract

Effects of tallow, choice white grease, palm oil, corn oil, or soybean oil on apparent total tract digestibility of minerals in diets fed to growing pigs

Merriman, L. A., C. L. Walk, C. M. Parsons, and H. H. Stein. 2016. Effects of tallow, choice white grease, palm oil, corn oil, or soybean oil on apparent total tract digestibility of minerals in diets fed to growing pigs. J. Anim. Sci. 94:4231-4238. Link to full text (.pdf)

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Requirement for digestible calcium by eleven- to twenty-five–kg pigs as determined by growth performance, bone ash concentration, calcium and phosphorus balances, and expression of genes involved in transport of calcium in intestinal and kidney cells

González-Vega, J. C., Y. Liu, J. C. McCann, C. L. Walk, J. J. Loor, and H. H. Stein. 2016. Requirement for digestible calcium by eleven- to twenty-five–kilogram pigs as determined by growth performance, bone ash concentration, calcium and phosphorus balances, and expression of genes involved in transport of calcium in intestinal and kidney cells. J. Anim. Sci. 94:3321-3334. Link to full text (.pdf)

Effect of increasing concentrations of digestible calcium and digestible phosphorus on apparent total tract digestibility of calcium and phosphorus by pigs

González-Vega, J. C., C. L. Walk, M. R. Murphy, and H. H. Stein. 2016. Effect of increasing concentrations of digestible calcium and digestible phosphorus on apparent total tract digestibility of calcium and phosphorus by pigs. J. Anim. Sci. 94(E-Suppl. 5):459 (Abstr.) Link to abstract (.pdf)

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Digestible calcium requirement for 100 to 130 kg pigs

Merriman, L. A., C. L. Walk, C. M. Parsons, and H. H. Stein. 2016. Digestible calcium requirement for 100 to 130 kg pigs. J. Anim. Sci. 94(E-Suppl. 5):458 (Abstr.) Link to abstract (.pdf)

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The effect of microbial phytase on the apparent and standardized total tract digestibility of calcium in feed ingredients of animal origin

Merriman, L. A., C. L. Walk, and H. H. Stein. 2016. The effect of microbial phytase on the apparent and standardized total tract digestibility of calcium in feed ingredients of animal origin. J. Anim. Sci. 94(Suppl. 2):110 (Abstr.) Link to abstract (.pdf)

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Effect of fat sources on ATTD of minerals

Merriman, L. A., C. L. Walk, and H. H. Stein. 2016. Effect of fat sources on ATTD of minerals. J. Anim. Sci. 94(Suppl. 2):104 (Abstr.) Link to abstract (.pdf)

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Digestible calcium requirements for 25 to 50 kg pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2016. Digestible calcium requirements for 25 to 50 kg pigs. J. Anim. Sci. 94(Suppl. 2):101 (Abstr.) Link to abstract (.pdf)

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Requirements for digestible Ca by growing pigs

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)

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Requirement for digestible calcium by 25 to 50 kg pigs at different dietary concentration of phosphorus by growth performance and bone ash concentration

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.

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Digestible calcium requirements for 25 to 50 kg pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2015. Digestible calcium requirements for 25 to 50 kg pigs. Memorias XVII Congreso Bienal AMENA. Puerto Vallarta, Jal. Mexico. Link to full text (.pdf)

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Effect of phytate, microbial phytase, fiber, and soybean oil on calculated values for apparent and standardized total tract digestibility of calcium and apparent total tract digestibility of phosphorus in fish meal fed to growing pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2015. Effect of phytate, microbial phytase, fiber, and soybean oil on calculated values for apparent and standardized total tract digestibility of calcium and apparent total tract digestibility of phosphorus in fish meal fed to growing pigs. J. Anim. Sci. 93:4808-4818. Link to full text (.pdf)

Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2015. Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs. J. Anim. Sci. 93:2255-2264. Link to full text (.pdf)

Digestible calcium requirements and calcium and phosphorus balance for weanling pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2015. Digestible calcium requirements and calcium and phosphorus balance for weanling pigs. J. Anim. Sci. 93(Suppl. 2):51-52 (Abstr.) Link to abstract (.pdf)

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Effect of fiber and fat on calculated values for standardized total tract digestibility of calcium in fish meal

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2014. Effect of fiber and fat on calculated values for standardized total tract digestibility of calcium in fish meal. J. Anim. Sci 92(E-Suppl. 2):231-232 (Abstr.) Link to abstract (.pdf)

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Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs

Calcium supplementation is important for swine diets because most commonly used feed ingredients have low concentrations of calcium. In a typical corn-soybean meal diet for a growing pig, the corn and soybean meal contribute only about 16% of the total calcium, with the rest coming from supplements. Apparent total tract digestibility (ATTD) values for calcium have not been reported for many common ingredients, and no values for the standardized total tract digestibility (STTD) of calcium have been reported. Therefore, an experiment was conducted to determine the ATTD and STTD of calcium in five calcium supplements.

An additional objective was to test the hypothesis that inclusion of microbial phytase in the diets increases the ATTD and STTD of calcium. Results of previous research has indicated that inclusion of microbial phytase in swine diets often increases the digestibility of calcium, but the effect of phytase on the STTD of calcium in individual ingredients has not been reported.

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Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2014. Effects of microbial phytase on apparent and standardized total tract digestibility of calcium in calcium supplements fed to growing pigs. J. Anim. Sci. 92(Suppl. 2):36 (Abstr.) Link to abstract (.pdf)

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The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility

González-Vega, J. C., C. L. Walk, Y. Liu, and H. H. Stein. 2014. The site of net absorption of Ca from the intestinal tract of growing pigs and effect of phytic acid, Ca level and Ca source on Ca digestibility. Arch. Anim. Nutr. 68:126-142. Link to full text (.pdf)

Determination of endogenous intestinal losses of calcium and true total tract digestibility of calcium in canola meal fed to growing pigs

González-Vega, J. C., C. L. Walk, Y. Liu, and H. H. Stein. 2013. Determination of endogenous intestinal losses of calcium and true total tract digestibility of calcium in canola meal fed to growing pigs. J. Anim. Sci. 91:4807-4816. Link to full text (.pdf)

The site of absorption of calcium from the intestinal tract of growing pigs

González-Vega, J. C., C. L. Walk, and H. H. Stein. 2013. The site of absorption of calcium from the intestinal tract of growing pigs. J. Anim. Sci. 91(Suppl. 2):74 (Abstr.) Link to abstract (.pdf)

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