Correction factors for weight productive traits up to weaning in the Bruna dels Pirineus beef cattle breed

Correction factors for sex of the calf, birth type and age of dam have been calculated regarding birth weight (BW), weaning weight (WW) and average daily weight gain (DWG) in the Bruna dels Pirineus breed. Standard deviations were heterogeneous for the two levels of sex and homogeneous for the two levels of birth type. Therefore, multiplicative correction factors were better for the sex of the calf, whereas additive correction factors were better for birth type. An age of dam correction resulted in either homogeneous (WW and DWG) or heterogeneous (BW) standard deviations depending upon the trait considered. It was observed that in general the additive correction was better, although this correction failed to completely homogenise the standard deviations within the levels of age of the dam for the respective variables.