This study was conducted to investigate the different levels of dietary cation-anion difference of anionic close-up diet on rumen fermentation and ruminal digestion characteristics in a dual-flow continuous culture system.

The effects of dietary cation-anion difference on sow calcium metabolism and relative indexes;

Ten mid-lactation Holstein cows were assigned randomly to A or B,and administration time-dependent influence of dietary cation-anion difference on performance,acid-base balance under summer condition in dairy cows were studied with the same ion salt.

This thesis studies the influence of dietary cation-anion difference and its administration time on lactation performance, the effect of season on milk production, and the relation of thermal environment and physiological reaction, hoping that it can provide a theoretical basis for dairy cow management at hot summer in Wuhu and other southern areas.

15 cows in early lactation were selected respectively in a replicated 3×3 Latin square design,and were assigned randomly into 3 groups, each with 5 replicates to study the effects of dietary cation-anion balance(DCAB) on performance and blood biochemical parameters of them in hot enviroment.

In the condition of heat stress, dietary cation-anion balance had a significantly effects on production and health of dairy cow.