12 October 2021

Indoor management of weanling replacement heifers

Over winter management of replacement heifers is crucial to achieve the target weight gain required for successful rearing. George Ramsbottom, Dairy Specialist, outlines the actions that must be taken to achieve adequate gains.

Target live weight and thus the required gain depends on the heifer’s maintenance sub index – see Table 1 for target weights around housing and pre-breeding for various maintenance sub indices. A live weight gain of at least 0.5kg/day and 0.7 kg/day are required for on-target and lighter heifers over the winter period. The aim is firstly to ensure that all heifers are at planned pre-breeding target liveweight at the start of the breeding season; and secondly to ensure that variation in liveweight is minimised. 

To achieve such gains the following actions need to take place now:

1. Treat heifers for parasites at or shortly after housing.
2. Segregate light from on-target/above target heifers.
3. Feed heifers according to the quality of the silage and liveweight.
1. On 67% DMD well preserved grass silage underweight heifers will require 1.5-2.0 kg concentrate/day.
2. Reduce allowance by 1kg/day if silage is 5% higher DMD / heifers are at or above target weight.
4. Ensure that there is 0.3m (1ft) of feeding space per heifer – particularly the lighter heifers available at all times while they are indoors or performance will be reduced.
5. Plan to turn the lighter heifers out to grass in early February – heifers will gain 1kg /day on spring grass alone or on a combination of grass and meals if grass is scarce.

Table 1: Target 1^st November 2021 and 1^st May 2022 live weights for replacement heifers of different maintenance sub indices

If you liked this you might also be interested in Managing Body Condition Score in Late Lactation.
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