Increase in inbreeding leads to loss in fitness and reduction in production traits. Although its effects are clear, measuring inbreeding is often complicated by the lack of complete and error free pedigrees. Availability of high-density marker panels provide an alternative tool to assess inbreeding. Additionally, inbreeding depression seems to be affected not only by the animal level of inbreeding but also by its parent’s inbreeding. The aim of this study was to determine the effects of the animal and its parent level of inbreeding on growth and female fertility in a small population of Hereford cattle. Inbreeding levels were assessed based on pedigree (Fped), genomic relationship matrix (FGRM), and runs of homozygosity (FROH). The pedigree consisted of 10,476 animals spanning over 48 generations. Genomic-based inbreeding was evaluated using 788 animals genotyped for 30,810 single nucleotide polymorphisms (SNPs). Traits analyzed included growth (birth weight, weaning weight, yearling weight, and average daily gain (ADG, kg/day) and female fertility traits (age at first calving and heifer pregnancy status). The phenotypic data consisted of records on growth and fertility traits on 3,995 animals. Linear regression analyses were used to assess the effects of inbreeding. The percentage average inbreeding was 29.01 (SD = 5.75), 14.80 (SD = 10.53) and 22.91 (SD = 5.14) for Fped, FGRM, and FROH, respectively. This high inbreeding was expected given the small size and the level of isolation of the population used in this study. An increase of 1% in animal inbreeding resulted in a decrease of 107, 36, and 110 kg in yearling weight for Fped, FGRM, and FROH, respectively. Similarly, ADG was reduced by 0.19 to 0.60 kg. Inbreeding increased significantly the age at first calving but not the pregnancy status. Joint estimates of animal (FA) and its sire’s (FS) or dam’s (FD) inbreeding effects showed a clear effect of FD on the progeny performance. The sire inbreeding has limited to no effects. The high inbreeding level of the studied population seems to have affected both production and fertility traits.