title: Improving reproductive efficiency in range cattle: An application of the O'Connor Management System.
abstract: One group of 125 Hereford cows from a range herd served as a control, while five management techniques were utilized to determine if reproductive performance could be maximized in another similar group from the same ranch. These five techniques were 60-d calving season, cows in moderate body condition at calving time, calf removal for 48 h at the start of breeding season, cows gaining weight near breeding time, and cows bred by bulls predicted to have high fertility (O'Connor Management System). Under the O'Connor Management System, 6% more cows became pregnant, 14% more weaned calves and calves were born 24 d earlier in the calving season. Consequently, calves weighed 14 kg more at weaning and net profit was increased approximately $39 per cow for cows in the O'Connor system.
authors.affiliation: Animal Science Department Brigham Young University Provo, Utah 84602 USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Anderson
authors.forename: H L
authors.initials: HL
authors.lastname: Fillmore
authors.forename: J N
authors.initials: JN
authors.lastname: Wiltbank