Reproductive efficiency and profitability of weaned lambs in hair sheep production systems in Northeast Mexico

摘要

Theeffectsofseasonoflambing(EP)andparity(NP)onproductivityinPelibuey(Pb)andBlackbelly(Bb)ewesweredeterminedundertwoproductionsystems,anintensive(Mirasol,Guemez,Tamps.,Mexico)andasemi-intensive(Cimarron,Llera,Tamps.,Mexico)productionsystem.Inaddition,theinformationonproductivityoftheintensivesystem(Mirasol)wasusedtodeterminetheequilibriumpointforthecostofthekgoflambweaned(PEk).ParturitiondatafromCimarr#243;n(1996to1998)andMirasol(1997)wereusedtodeterminetheeffectsofEPandNPonthenumberoflambsborn(NC)andlambing(Pnac)andweaningweights(Pdest)inthetwoproductionsystems.Theproductivityandtheproductioncosts(fixedandvariable)inMirasolwereusedtodeterminethePEk.TheNCwasnotaffectedbyEPorNP,themeanNCwas1.48lambs,themeansforEPandNPvariedfrom1.35to1.67andfrom1.39to1.55lambs.ThemeanPnacwas3.63kg,EPaffected(P0.05)thePnaconlyforthefirstandsecondparturitions;whereas,NPaffected(P0.05)onlythemeantotalsforPnac.TheresultsindicatedthattherewerenosignificanteffectsofEPorNPonPdest,however,therewasatendencyforPdesttodecreasefromthestarttotheendoftheyear;whichsuggestedpossibleseasonalvariations.TherewasaninverserelationshipbetweenPEkandtheNCandPdest,whentheproductioncostperewewas$701.67andthemarketpriceforthekgoffinishedlambwas$20.00(U.S.dollarexchangerateat10pesosperdollar),thePEkdecreasedasNCandPdestincreased.TheseresultsindicatedthattheNC,PnacandPdestvariedaccordingtotheEPandtheNPandpossiblywithotherenvironmentalandmanagementfactors;ontheotherhand,PEkindicatedthatproductioncostsarehighinrelationtothemarketpriceforslaughterlambs,forthisparticularsheepproductionsystem.