Heifer growth targets: feeding, weight and breeding

What weight should heifers reach before breeding?

Aim for about 55% of mature weight at breeding and about 82% at first calving. These commonly used NRC 2001 targets relate heifer growth to the size of adult cows in your herd. For example, at a mature weight of 650 kg, the targets are about 358 kg at breeding and about 533 kg after calving. Use the herd’s mature weight, or an estimate, to set your targets. Weigh heifers regularly and compare each group’s progress with its target.

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How much dry matter does a growing heifer need?

A growing heifer’s dry matter intake depends on her current weight and expected mature weight. NASEM 2021 Equation 2-3 estimates daily intake as 0.022 × mature weight × (1 − e^(−1.54 × body weight ÷ mature weight)), with weights in kg. For example, at a mature weight of 650 kg, estimated daily dry matter intake is 4.28 kg at 150 kg body weight, 6.39 kg at 250 kg, 8.06 kg at 350 kg and 9.38 kg at 450 kg. Use measured intake when available. The feeding plan must also cover energy for maintenance, body growth and pregnancy.

How do you plan a ration for growing heifers?

Group heifers by weight and plan a ration for each group. Choose your forage, concentrate and mineral mix in HerdMobile to calculate daily quantities and cost per head. Forage-based rations with enough fibre suit growing heifers. Weigh a sample from each group every month, note the gain and adjust the ration as animals reach the next weight range. Keep birth, breeding and weight notes for each heifer so you can follow her progress. Provide enough trough space for every animal, with clean water always within reach.