Effect Of Different DCAD Levels Of Diet In Perinatal Period On Physiological Indexes In Serum,Health And Performance In Dairy Cows

This experiment was conducted to evaluate the effects of dietary cation-anion difference(DCAD)level on postpartum health status and Physiological Indexes in Serum of peripartum dairy cows.The test was adopted single factor randomized block design.Twenty Holstein antepartum cows(28 d)with the same age and body weight were allocated into 4 groups and 5 cows per group.Cows were fed 4 experimental diets with DCAD levels at +262.31mEq/kg DM(Control group),+130.26mEq/kg DM(Trial groupⅠ),+78,51mEq/kg DM(Trial group Ⅱ)and +667mEq/kg DM(Trial groupⅢ),respectively.The experiment lasted for 49 days with 7 days adaptation and 42 days trial duration.The results showed as follows:(1)Decreasing the DCAD level of dietary in dairy cows can improve serum calcium concentration significantly(P<0.05),decreasing serum NEFA within a week after delivery significantly(P<0.05),decreasing urine pH significantly(P<0.05),improving the anti-oxidant capacity in serum of calves significantly(P<0.05)and improving postpartum serum level of vitamin D significantly(P<0.05)but there is no significant effect on serum parathyroid hormone and calcitonin concentration in dairy cows(P>0.05).Regulating the DCAD level of perinatal ration DCAD as ＋78.51mEq/kg DM can improve the level of calcium in serum in postpartum Holstein cows and reduce the incidence of ketosis effectively.(2)Decreasing the DCAD level of dietary in dairy cows can improve the trial group Ⅲ(DCAD=+6.67mEq/kg DM)level of postpartum serum TNF-α in dairy cows 7th day and the 14th day prenatal significantly(P<0.05),improve the level of the Serum IL-1(3 in postpartum Holstein cows of trial group Ⅱ(DCAD=+78.51 mEq/kg DM)the 7th Day and the 7th day prenatal Significantly(P<0.05).Regulating the DCAD level of perinatal ration DCAD as +78.51mEq/kg DM can improve the health of dairy cows effectively.(3)Decreasing the DCAD level of dietary in dairy cows can reduce the amount of dry matter intake significantly(P<0.05)in the early perinatal period,improve the milk fat rate significantly(P<0.05)in the 7th day postpartum,but there is no significant effect on average daily milk yield from first to eighth lactation month(P>0.05).The incidence of postpartum hoof disease decreased by 60%;Regulating the DCAD level of perinatal ration DCAD as +78.51mEq/kg DM can improve the health and production performance of postpartum Holstein cows.