Survival, growth and reproductive performance in F1 crossbred cattle produced and managed on station in the Gambia

摘要

Inatrialwherebyalargenumberofcowswereneededtocalveatapproximatelythesametime,opportunitywastakentoestablishacrossbredcowpopulationattheInternationalTrypanotoleranceCentre(ITC).Aslightimprovementinthetraditionalhusbandrysystemrevealedagreatproductivitypotentialofthesecrossbreds.Theirsurvivalratetooneyear(i.e.,90.0%fortheJerseyxN'Dama(JxN)and71.2%fortheFriesianxN'Dama(FxN))wasprovedsatisfactoryinthelocalenvironment,thoughconclusionsarethatmoreattentionisneededforrearingFriesiantypeF1calvesinthetropicalenvironment.Withanoverallmeanbirthweightof17.7±4.1kgandanoverallmeandailyweightgain(DWG)of0.220±0.104kgtheyattainedanaverageweightof100.6±29.9kgatoneyear.Theirrelativelyretardedgrowthrecommendedabettermanagement.Pubertywasattainedat478.2±13.9days,ageatfirstcalving970.5±94.1daysandtheoverallmeancalvingintervalandopenperiodwere400±82.5and117#177;83.2days,respectively.ThesereproductiondatashowedthatthecrossbredsmatureearlierandhaveshortercalvingintervalsthantheN'Damabreed.