Beyond the Barn: Have a Plan When Growing Heifers
Heifer weight at calving is an important determinant of first lactation performance. Our goal is to achieve 82 percent of mature size to achieve 80 percent of mature cow milk yield. Having a plan and setting benchmarks for heifer growth and development is key to successful replacement heifer development. The list below summarizes phases of growth and target weight at the end of each growth phase, as well as important highlights and factors that affect growth in each phase.
Growth phase: Nursery
Target weight at phase end: 190 pounds (at least double bodyweight from birth to weaning)
- Set the slope of the growth curve; take advantage of feed efficiency; health is the priority.
- Balance nutrient intake from milk and starter to grow calves from the inside out.
Growth phase: Transition
Target weight at phase end: 250 pounds
- Maintain the growth rate; health is the priority; develop social feeding behavior.
- Rumen health and functionality drive energy and protein digestion and, therefore, growth and health.
Growth phase: Puberty
Target weight at phase end: 650 pounds (reach 45 percent mature bodyweight)
- Early puberty at 9 to 10 months old indicates physiological maturity, and reproductive hormones impact mammary gland maturation.
- Early puberty results in increased number and strength of estrus cycles, which appear to alter mammary gland physiology and increase reproductive efficiency.Achieving puberty earlier, but waiting to breed at 12 to 13 months of age, allows for adequately mature heifers to calve at 23 to 24 months of age.
Growth phase: Breeding
Target weight at phase end: 900 pounds (reach 55 to 60 percent mature bodyweight)
- Maximize reproductive efficiency by targeting calving age at 22 to 24 months of age.
- Minimizing variation in age at conception allows the downstream heifer nutrition and management programs to function much more efficiently.
Growth phase: Calving
Target weight at phase end: 1,400 pounds (calve in heifers at 80 to 85 percent mature bodyweight)
- Heifers need to gain at 2.2 pounds per day from three to 20 months of age to hit the target weight of 1,400 pounds at calving. Heifer weight gain during the last trimester is mostly calf and fetal membranes and does not accurately reflect heifer growth.
- Heifers that do not achieve growth goals by 21 months of age will have decreased ability to consume adequate amounts of lactation TMR to milk at 80 percent of mature cow levels.
Business and economics
Calf and heifer nutrition
Starting Strong - Calf Care
Transition and reproduction