A correct relationship among sires is essential for an efficient breeding program. Microsatellite markers were used in progeny tests, to assess the paternity of seventy-four probable offspring of nine Gir dairy sires. A 36% misidentification rate was observed; however, these errors had minimal effects on the ranking of the nine bulls with regard to their genetic values. The results suggest that paternity tests should be performed in breeding programs, in order to prevent inappropriate paternities from influencing the genetic value of bulls in the future.

Oitenta e oito vacas da raça Holandesa e 88 touros da raça Gir foram genotipados através da PCR para o gene CD18 da deficiência de adesão de leucócitos em bovinos (BLAD). As freqüências do alelo mutante BLAD e de vacas heterozigotas da raça Holandesa foram 2,8 e 5,7%, respectivamente. Por outro lado, todos animais Gir foram identificados como homozigotos normais, ou seja, nenhum alelo mutante BLAD foi encontrado. Estes resultados sugerem que a mutação no gene CD18 é prevalente em bovinos brasileiros da raça Holandesa e ausente ou presente numa freqüência muito baixa em animais Gir.

Bovine leukocyte adhesion deficiency (BLAD) is a disease known to affect the Holstein cattle breed throughout the world. Eighty-eight Holstein dairy cows and 88 Gir dairy bulls were genotyped by PCR for the CD18 BLAD alelle. The frequency of the BLAD mutant allele and the BLAD-carrier prevalence in Brazilian Holstein cows were 2.8 and 5.7%, respectively. No mutant allele was found in any of the 88 Gir animals. We conclude that the CD18 gene mutation is prevalent in Brazilian Holstein cattle and absent or present at a very low frequency in Gir cattle.