Evaluation of cation-anion diets in calcium metabolism in ruminants

The objective of this study was to evaluate the use of the dietary cation-anion balance (DCAB) on the calcium metabolism in male Nellore steers with a mean age of 10 months. Three experimental diets were tested: a cationic diet, a diet consisting of Tifton hay only, and an anionic diet with +15.2, +23.9 and −10.0 mEq/100 g DM of DCAB values in the diet. The anionic diet was calculated as the addition of salts of ammonium chloride and magnesium sulfate. Based on the isotope dilution technique, the negative DCAB value used in this study (−10.0 mEq/100 g DM) does not affect calcium metabolism, especially endogenous losses and true absorption.

本研究旨在评估饲粮阴阳离子平衡（dietary cation-anion balance, DCAB）对平均月龄为10个月的内洛尔阉牛钙代谢的影响。本试验共设置3种试验饲粮进行测试：阳离子饲粮、仅含提夫顿干草（Tifton hay）的饲粮，以及阴离子饲粮，三者的DCAB值分别为+15.2、+23.9和−10.0 mEq/100 g 干物质（dry matter, DM）。该阴离子饲粮通过添加氯化铵与硫酸镁盐配制而成。基于同位素稀释技术（isotope dilution technique），本研究中使用的−10.0 mEq/100 g 干物质的负向DCAB值不会对钙代谢产生影响，尤其不会影响内源损失与真吸收。