Effect of restricted suckling on performance of Shorthorn and Sahiwal cows and calves in Pakistan

摘要

TwentycowsdrawnfromamixedpopulationofAustralianIllawarashorthorn(AIS),Sahiwal(S),theirfirstcrosses(F1)andbackcrossestoAIS(B1)wereallocatedtoeitherartificialrearing(AR)orrestrictedsuckling(RS)treatments.ThebreedmakeupofthetreatmentwasslightlyconfoundedwithARandRShavingS:2,6;F1:1,1;B1:6,2andAIS:1,1.Feedingofthecowswasbasedongreenfodderandconcentrates.Thecalvesreceivedwholecows'milkbynipplepail(AR)orrestrictedsucklingfora30minuteperiodfollowingmilking(RS);bothgroups(ARandRS)werehousedtogetherandhadfreeaccesstogreenforageandconcentrates.Milkingwasbymachinetwicedaily.Experimentaldatawerecollectedforthefirst92daysoflactation/calfgrowth,thenmilkfeeding/sucklingwasstoppedforbothtreatments.Calvesrearedbyrestrictedsucklinggainedweightfaster(552quot;32vs370quot;32g/d)andagreaterproportionofweightwasintheformoftissue(betterconditionscore)ascomparedwithartificialrearing.Theyconsumedlessmilk(2.67vs3.04kg/d)andhadamuchbetterconversion(4.97vs8.98)ofmilkintoliveweight.Sahiwalcowsgavemorethandoublethequantityofmilkwhentheysuckledtheircalvesaftermilkingascomparedtotheartificialrearingsystem.ThemilkyieldofAIScowsandtheircrosseswasnotaffectedbythecalfrearingmethod.