Managing dairy replacement heifers

DAIRY farmers are mostly concerned with drying-off cows at this time of year as well as keeping grass in front of the remaining cows that are milking.

Replacement heifers and in-calf heifers on dairy farms can tend to be forgotten about.

However maiden heifers generally represent the best genetics available for future milk production and should be looked after.

Well-bred maiden heifers have the potential to substantially impact on herd profitability.

Light heifers at calving down will have reduced milk yield (400 LITRES) in their first lactation and a higher proportion of them will not go back in-calf.

Achieving target live weight gains is an integral part of the heifer rearing system.

The target live weights (Kg) for Holstein Friesian, British/ New Zealand Friesian and Jersey X Friesian replacement heifers at this time of year are 470kgs, 445kgs and 410kgs respectively.

If in calf heifers are under target weights in October they should be fed 1-2 kgs of meal at grass.

It might be a good idea to house in calf heifers early and put them on a programme to reach good weights when calving down.

Weanling replacements heifer target weights for the same breeds at this time of year are 220kgs, 210kgs and 195kgs respectively.

If your heifers are not making these weights now is the time to take action.

Ideally, heifers should be weighed to determine how many of the animals are below their target weight for the time of the year.

If underweight heifers are found, there really is only one option at this time of year and that is to feed meal to gain weight.

Separate out the heifers that are under target weight immediately and introduce concentrates.

Decide on how much meal is needed. Weanlings of 200 kg will eat about 2.3% of their bodyweight, which is about 4.5 kg of grass dry matter per day.

Where there is adequate grass no meals are required unless the heifers are underweight.

However where grass is scarce then 1-2 kg meal must be fed.

Close heifer grazing ground as you would dairy ground and aim to have yearlings at grass as early as possible in spring.

Silage fields in spring are ideal for grazing yearlings especially those away from the milking block.

Just a word on safety - when feeding meals to in-calf heifers or weanlings in the field be very careful to avoid getting trampled.