Effects of different levels of dietary calcium on calcium and phosphorus kinetics in horses

Author(s)

Dorinha Miriam Silber Schmidt Vitti ^[1] ; Carlos Eduardo Furtado ^[2] ; João Batista da Silva Quadros ^[3] ; João Batista Lopes ^[4] ; Ives Cláudio da Silva Bueno ^[5] ; Eduardo Fernando Nozella ^[6] ; Patrícia Barboza de Godoy ^[7]

Affiliation

^[1] Centro de Energia Nuclear na Agricultura - Brasil

^[2] Universidade Estadual de Maringá

^[3] Universidade Estadual de Maringá

^[4] Universidade Federal do Piauí

^[5] Centro de Energia Nuclear na Agricultura - Brasil

^[6] Centro de Energia Nuclear na Agricultura - Brasil

^[7] Centro de Energia Nuclear na Agricultura - Brasil

• Document type: Journal article
• Source: REVISTA BRASILEIRA DE ZOOTECNIA-BRAZILIAN JOURNAL OF ANIMAL SCIENCE; v. 37, n. 3, p. 478-486, 2008-03-00.
• Field of knowledge: Agronomical Sciences - Animal Husbandry

Abstract

This experiment was carried out to study calcium (Ca) and phosphorus (P) kinetics of growing horses fed diets with different Ca levels: 0.15%, 0.45, and 0.75%, using a deterministic and compartmental model. The information on metabolism and kinetic of Ca and P in tissues was obtained by the isotopic dilution technique. Dietary Ca levels influenced Ca true absorption, showing lower value (4.97 g Ca/day) for the Ca level of 0.15%. The changes of Ca between the blood and digestive tract were lower for 0,15% Ca. The flows between the blood and bone and blood and soft tissues did not show differences between treatments, but bone and tissue balance was lower for the level of 0.15%. Dietary Ca levels influenced on P in urine and values were higher for 0.15% (2.49 g P/anim.day). The mean true P absorption was of 83%, with no differences among treatments. Bone deposition of 9.69g P/anim.day was observed, showing that the amount of P fed was adequate in relation to the allowed amplitude for Ca:P ratio for the specie in the studied animal category. No differences between the P flows in the diverse compartments, for interference of the metabolism model. The ingestion of increasing levels of Ca affected the metabolism and the kinetic of this element, however Ca:P ratio is the predominant factor to determine the excretion, retention and absorption of Ca. The Ca deposition in bone is influenced by the amount ingested of this mineral. The P metabolism in growing horses was not affected by Ca levels. The amount of 13.4 g P/anim.day in the diet was sufficient to maintain P metabolism at normal standard levels. (AU)

• FAPESP's process: 04/14532-5 - Environmental impact of phosphorus excretion in livestock: quantitative analysis of flow phosphorus using bio-mathematical models
• Grantee: Dorinha Miriam Silber Schmidt Vitti
• Support Opportunities: Research Projects - Thematic Grants