preston39
Well-known member
Posted from Cow-calf-weekly.
"Develop Heifers To 50% Or 55% Of Mature Body Weight
For many years, it was recommended yearling heifers be developed to reach 60-65% of their projected mature body weight (MBW) prior to the start of their first breeding season. Recent research indicates this recommendation may be lowered to 55% of MBW without jeopardizing first- and second-calf conception rates.
In a three-year University of Nebraska study, a total of 261 March-born heifer calves were developed to reach either 55% of MBW prior to a 45-day breeding season, or 50% of MBW prior to a 60-day breeding season.
Extending the breeding season by 15 days for the heifers developed to 50% of MBW resulted in pregnancy, calving and weaning rates comparable to heifers developed to 55% of MBW. And reduced development costs in the 50% system more than offset reduced income from lighter weaning weights caused by later calving dates, resulting in lower costs to produce one pregnant yearling heifer or two-year-old cow.
The results suggest developing heifers to 50% of MBW prior to their first breeding season is a feasible alternative for some producers (Creighton et al. 2005. Univ. of Nebraska Beef Cattle Report MP 83-A).
-- Michigan State University "Beef Cattle Research Update," Spring, 2005 "
"Develop Heifers To 50% Or 55% Of Mature Body Weight
For many years, it was recommended yearling heifers be developed to reach 60-65% of their projected mature body weight (MBW) prior to the start of their first breeding season. Recent research indicates this recommendation may be lowered to 55% of MBW without jeopardizing first- and second-calf conception rates.
In a three-year University of Nebraska study, a total of 261 March-born heifer calves were developed to reach either 55% of MBW prior to a 45-day breeding season, or 50% of MBW prior to a 60-day breeding season.
Extending the breeding season by 15 days for the heifers developed to 50% of MBW resulted in pregnancy, calving and weaning rates comparable to heifers developed to 55% of MBW. And reduced development costs in the 50% system more than offset reduced income from lighter weaning weights caused by later calving dates, resulting in lower costs to produce one pregnant yearling heifer or two-year-old cow.
The results suggest developing heifers to 50% of MBW prior to their first breeding season is a feasible alternative for some producers (Creighton et al. 2005. Univ. of Nebraska Beef Cattle Report MP 83-A).
-- Michigan State University "Beef Cattle Research Update," Spring, 2005 "