01091nam a2200205 a 450000100080000000500110000800800410001910000280006024500840008826000390017230000100021150000180022152005280023965000160076765000160078365000180079965300200081765300210083765300270085814014412024-09-19       1968    bl uuuu  m   00u1 u    #d1 aNASCIMENTO, C. N. B. do  aHeterotic and environmental effects in rotational crossbreeding of beef cattle.  a[S.l.]: Texas A&M Universityc1968  a84 p.  aM.Sc. Thesis.  aTo determine the productivity of Brahman, Hereford, and crossbred cattle measured by pregnancy, calving and weaning percentages of cows and weaning weight of calves. To estimate the yield of milk produced by crossbred, Brahman and Hereford cows. To determine the relationship of yield of milk produced by Brahman, Hereford and crossbred cows to growth rates and weaning weights of their calves. To evaluate the effect of sex, year and month of birth as well as breed or cross of calf, and age of dam on calf weaning weight.  abeef cattle  aweight gain  aGanho de Peso  aBovino de corte  aGenetic breeding  aMelhoramento genético