01738naa a2200301 a 450000100080000000500110000800800410001910000170006024501100007726000090018750000110019652009010020765000160110865000170112465000120114165000160115365000180116965000180118765000240120565300200122965300120124965300130126165300130127465300220128765300110130970000200132077300960134013233382007-09-11       2002    bl uuuu     u00u1 u    #d1 aBIANCHIN, I.  aMosca-dos-chifre, Haematobia irritansbcomportamento e danos em vacas e bezerros Nelore antes da desmama.  c2002  aCNPGC.  aThe hornfly and losses caused by it in Nellore cows and pre-weaning calves where studied, using two groups of 60 animals each, one group with a natural infestation and the other without hornfly, during four consecutive years. It was seen that the number of flies on the cows did not exceed an average of 80 flies/animal in all years of observation. The majority of the cows (83%) had few flies, whereas 17% had larger numbers. The calves were infested with few flies. Rainfall in excess of 100 mm during short periods diminished fly infestation. Weight gain in the cows without flies (treated with insecticides) as well as their calves was greater than in the control cows, but not statistically significant (P&gt0.05). Mean percentage pregnancy during the four years was 15% more in treated cows than the non-treated animals, and this difference was probably due to the infestation of the bulls.  abeef cattle  aepidemiology  aNellore  aweight gain  aEpidemiologia  aGanho de Peso  aHaematobia Irritans  aBovino de corte  aControl  aControle  aHorn fly  aMosca-dos-chifres  aNelore1 aALVES, R. G. O.  tPesquisa Veterinária Brasileira, Rio de Janeirogv. 22, n. 3, p. 109-113, jul./set.. 2002.