Variance components, genetic parameters, and breeding values for birth weight in Brown Swiss cattle reared in Bahri Dagdas. International Agricultural Research Institute were estimated by REML-BLUP procedures using MTDFREML computer programme. Six different animal models were fitted for the trait ranging from a simple to the most comprehensive model. The most detailed model (model 6) provided the best fit to the used dataset. Heritability was higher in the model without maternal effect. Although maternal effect had a significant place for the data, environmental effect due to dam was not important. Heritability (h(2)), maternal heritability (m(2)), and the genetic correlation between these 2 parameters (r(AM)) were 0.15, 0.06 and 0.92, respectively, according best model (model 6). Breeding values were also calculated for the trait, but no positive or negative change has been observed between years. More detailed accurate data are needed to establish the applied method on the livestock sector in Turkey.