Data cleaningconsisted of the following procedures to ensure that heifersand cows that aborted, or that became pregnant during thebull breeding season did not contribute any further data tothe study: animals with GL < 266 days were either changedfrom “calved” to “aborted” if the birth weight of the calfwas below 25 kg and the calf did not survive, otherwise an (Denham et al., 1991; Engelken et al., 1991)