02039naa a2200253 a 450000100080000000500110000800800410001910000160006024501100007626000090018630000170019549000090021252013480022165000190156965000170158865000170160565000200162265000170164265300180165970000190167770000200169670000180171677300510173410799391999-08-27       1985    bl ---       0--  u    #d1 aBADINGA, L.  aEffects of climatic and management factors on conception rate of dairy cattle in subtropical environment.  c1985  ap.78-85 v.68  vv.68  aBreeding records, representing 12,038 inseminations at Bassett's Dairy Farm (Monticello, FL), were analyzed to document effects of environnmental and management factors on fertility of dairy cattle from January 1, 1975 to December 31, 1977. Conception rates of lactating cows decreased sharply when maximum air temperature on day after insemination exceeded 30 graus C. In contrast, conception rates for heifers did not decline until 35 graus C. Virgin heifers had higher conception rates for all services (50%) than lactating cows (34%) and suffered only slight depression on fertility during summer months. Heifers required 1.5 services per conception compared with 2.3 for lactating cows. Relationship between conception rate and rainfall on day after insemination was negative and curvilinear. Jerseys had higher conception rates (45%) than Holstein (39%) and Brown Swiss (41%). Services per conception were 1.7, 2.0, and 1.9. Substantial decreases of fertility were associated with advancing service number. Estrous status (standing; positive heat detection patch; mounting activity), inseminator, and year of service were related to variation of conception rate. Seasonal effects on fertility of lactating cows were marked. Thus, environmental management of the postpartum cow during hot summer months is warranted to maximize fertility.  abioclimatology  adairy cattle  areproduction  aBioclimatologia  aReprodução  aGado de leite1 aCOLLIER, R. J.1 aTHATCHER, W. W.1 aWILCOX, C. J.  tJournal of Dairy Sciencegv.68, p.78-85, 1985.