Tucker W B, Harrison G A, Hemken R W
Department of Animal Science, University of Kentucky, Lexington 40546.
J Dairy Sci. 1988 Feb;71(2):346-54. doi: 10.3168/jds.S0022-0302(88)79563-6.
Twelve lactating Holstein cows were blocked according to age and milk production into groups of three cows and assigned to three 4 x 4 Latin squares in a split-plot design with subtreatments. Treatments on each square were four diets formulated to provide -10, 0, +10, or +20 meq/Na + K) -Cl/100 g diet DM. The four balances were achieved on squares 1, 2, and 3 by manipulating Na, K, and Cl, respectively. Actual milk yield was 8.6% higher on +20 than -10 averaged across the three squares. Blood pH and bicarbonate increased linearly with dietary cation-anion balance. Rumen pH increased linearly with dietary cation-anion balance, but fermentation patterns were largely unaffected. Urine pH increased linearly and quadratically with increasing dietary cation-anion balance. Square times balance response differences proved nonsignificant for all parameters except blood bicarbonate and rumen isovalerate, indicating responses could be attributed to the dietary cation-anion balance itself rather than to the effects of a single ion. Regulation of dietary cation-anion balance may become a useful tool for improving the performance of lactating dairy cattle.
12头泌乳期荷斯坦奶牛按年龄和产奶量进行分组，每组3头，采用裂区设计和亚处理方式，分配到3个4×4拉丁方试验中。每个拉丁方的处理为4种日粮，分别提供-10、0、+10或+20 meq/（Na+K）-Cl/100 g日粮干物质。在第1、2和3个拉丁方中，分别通过调整钠、钾和氯的含量来实现这四种平衡。在三个拉丁方中，+20组的实际产奶量比-10组平均高出8.6%。血液pH值和碳酸氢盐含量随日粮阴阳离子平衡呈线性增加。瘤胃pH值随日粮阴阳离子平衡呈线性增加，但发酵模式基本不受影响。尿液pH值随日粮阴阳离子平衡的增加呈线性和二次方增加。除血液碳酸氢盐和瘤胃异戊酸外，拉丁方与平衡反应差异对所有参数均无显著影响，这表明反应可能归因于日粮阴阳离子平衡本身，而非单个离子的作用。调节日粮阴阳离子平衡可能成为提高泌乳奶牛生产性能的一种有用工具。
