Milk yield and reproductive performances of lactating cows as affected by intakes of certain dietary macro minerals in Ethiopia

摘要

Thisstudywasconductedtoinvestigatetheinfluencesofdietaryintakesofcertainmineralsonmilkyieldandreproductiveperformancesoflactatingcowsfedonconcentratesupplementwith/withoutcottonseedcakeand/orbolesoil.Thirty-twopregnantHolsteinFriesiancowswithaveragebodyweightof524#177;54kgwereblockedbytheirexpectedduedateofcalvingasearly(B1)andlate(B2).Soonaftercalvinganimalswereassignedinarandomizedcompleteblockdesigntooneofthefollowingfourdietarytreatments:concentratealone(control)(C),45%oftheconcentratedietbyweightsubstitutedwithcottonseedcake(C+CSC),concentrateplus3%bole(lakesoil)(C+Bole)and45%oftheconcentratesubstitutedwithcottonseedcakeplus3%bole(C+CSC+Bole)for135daysofdatacollection.StatisticallydailymilkyieldandFCmilkyieldwerenotifferentamongtreatments.However,animalsfedonthetreatmentdietsofconcentrate+CSC,concentrate+Boleandconcentrate+CSC+Bole,produced7.4,16.3and18.2%respectivelyhigheractualmilkand14.3,24.2and25.7%respectivelyhigher4%fatcorrectedmilkthanthecontrolgroup.InclusionofbolesoilaloneasamineralsourceorincombinationwithCSCsupportedhigherdailyactualandFCmilkproductionthanfeedingconcentratedietwithCSCalone.Daysfromcalvingtofirstestrus,daysopenandnumberofservicesperconceptionwerenotdifferentamongtreatments.Nevertheless,Shorterintervalsofdaysfromcalvingtofirstestrus,daysopenandlowestnumberofservicesperconceptionwererecordedforanimalsfedonconcentratedietwithbolesoilalonefollowedbythosefedthecontroldiet.Inclusionof3%bolesoilaloneappearedtoimprovebothmilkyieldandreproductiveperformancesofdairycattle.