Reproductive performance of Tswana and Simmental x Tswana crosses in smallholderfarms in Botswana

摘要

nbsp;DatafromtheSmall-scaleDairyProjectwereanalyzedtocomparethereproductiveperformanceofSimmental×TswanacrossesandpurebredTswanamilkingcowsfromsmallholderfarms.Theeffectsofseason(dryandwet),breedgroup(TswanaandSimmentalcrosses)andtheirinteractiononcalvingintervalanddaysopenweredetermined.Theeffectsofbreedandyearandtheirinteractiononcalvingrateweredetermined.Correlationofmonthlycalvingandmonthlyrainfallwascomputed.nbsp;TherewasnodifferenceincalvingintervalanddaysopenbetweenTswana(576±11.3and296±11.3days)andSimmentalcrosses(584±22.3and303±22.3days)cows.Therewerenoeffectsofseasononthecalvingintervalanddaysopen.Therewasalsonobreedxseasoninteraction.PeakcalvingoccurredbetweenOctoberandJanuary(52.3%)whilebetweenMayandJune15.3%ofcowscalved.ThemeancalvingrateofTswanacows(68.2%)tendedtobehigherthanthatof.Simmentalcrosses(62.5%)cows.Therewasasignificanteffectofyearoncalvingrate.Theimplicationsoftheresultsarediscussedinrelationtotheeffectsofbreedandseasononthereproductiveperformanceofthesebreeds.nbsp;