Performance of Hereford and two-breed rotational crosses of Hereford with Angus and Simmental cattle: II. Carcass traits of steers.

Calf carcass traits were evaluated for Simmental (S) x Hereford (H) and Angus (A) x H crosses in two-breed rotations and for straightbred H. Data were grouped into seven dam breed categories: straightbred Hereford (H), F1 S x H cows (SH), S x H cows of low percentage H (SHS), S x H cows of high percentage H (HSH), F1 A x H cows (AH), A x H cows of low percentage H (AHA) and A x H cows of high percentage H (HAH). Straightbred H and crossbred SH, AH, SHS and AHA cows were mated to H bulls, HSH cows were mated to S bulls and HAH cows were mated to A bulls. Calves from the S x H rotation produced heavier carcasses with less fat, lower quality grade, larger longissimus area and increased estimated cutability compared to A x H calves. Some significant intergenerational differences were observed within rotations, particularly within S x H. Calves from HSH cows mated to S bulls produced carcasses with less fat cover, lower quality grade, larger longissimus muscle area and higher estimated cutability compared to calves from SHS dams mated to H bulls. Within both rotations, evaluation of carcass weight per day of age indicated that postweaning ADG was lower for generations for which H was the sire breed. Carcass traits of calves from SHS, HSH, AHA and HAH dam breed groups from the last 3 yr of the study when calves were fed under two different postweaning management systems were evaluated in a separate analysis.(ABSTRACT TRUNCATED AT 250 WORDS)