By Debbie James

Calving heifers 60 days earlier is allowing a Pembrokeshire dairy farm to capture an additional £5,300 of profit.

Dylan and Hannah Harries had been calving heifer replacements at 23½ months but experimented with earlier breeding in the spring calving New Zealand Friesian x Jersey herd in 2017, serving 100 heifers at the end of January, at 20.9 months, instead of May.

The couple, who run Tyddyn y Eglwys, near Llanfyrnach, in a joint venture with the farm owners, Kim and Bryony Petty, are in their third year of using this approach and are reporting multiple benefits.

It generates additional milk income – with the butterfat and protein averages at 5.20 per cent and 3.72 per cent respectively, they calculate an additional income of £500/heifer in the first lactation based on a milk price of 30 pence per litre (ppl).

“Calving 100 heifers 60 days earlier equates to £5,300 extra profit after all costs,’’ Dylan calculates.

It also eases the spring workload and provides cashflow in January and February.

Dylan admits that the change of approach was initially the result of curiosity.

“We were wintering heifers on kale to stop them getting too fat and I started to question why we were going to great lengths to stop them getting over-conditioned when they could be putting milk in the tank.

“That seemed insane to me so we decided that instead of restricting their feed for the last three months of pregnancy we would calve them early and winter them indoors.’’

In February 2017, 96 heifers were served for one cycle at an average weight of 258kg and 51 of those held to service.

Those 51 calved in autumn 2018 at an average of 21.7 months and predicted to produced 7,136 litres of milk in their first lactation at 5.20 per cent butterfat and 3.72 per cent protein.

In comparison, heifers that were served to calve in spring 2019 calved at an average of 22.9 months and are predicted to produce 5,716 litres at a 4.91 per cent butterfat average and 3.60 per cent protein.

There was little difference in the fertility rate – the six week in-calf rate for the autumn calvers was slightly lower at 72 per cent compared to 76 per cent in the spring group but the 12 week in-calf rate for both groups was 92 per cent.

In autumn 2019 the average age of calving is even lower, at an average of 20.9 months, but this has had no detrimental effect on heifer health and performance.

“We haven’t used the calf puller once,’’ says Dylan, who uses Aberdeen Angus genetics on all the heifers.

Calves are weaned when they reach a target weight of 100kg at 10-12 weeks – daily liveweight gain target from birth to weaning is 0.75kg but weight gain is mostly nearer to 1kg/day.

Calves are turned out to grass from the end of March so are weaned at grass and graze until housing in November and early December.

An additional cost from calving earlier is a higher concentrate input in the first summer – concentrates at 1kg/day/head are delivered through a snacker during that first summer.

Dylan calculates this additional cost to be around £15 head.

Heifers are averaging 257.5kg at serving at 11.5 months/330 days.

This is 55 per cent of their mature weight compared to the recommended 60 per cent but the heifers that calved in autumn 2018 averaged 433.5kg, which is 90 per cent of their mature weight.

One of the difficulties that earlier calving presents is the logistical challenge of running the heifers as a separate group.

“Where it gets tricky is on a farm of this scale we are set up for running a mob of 500-600 cows and all of a sudden we have a mob of 100 heifers to deal with and the farm isn’t set up for that,’’ Dylan admits.

Their approach is to split the herd in half with the heifers in a group of 250 over the winter, a group which includes thinner cows and cows calving at the end of the spring calving block.

One of the drawbacks of earlier calving is that it does complicate the system.

“In the autumn we need an extra person because someone has to scrape the yard for the cows to come straight back onto the yard instead of turning them out as we would in the spring and bringing them back in again,’’ says Dylan.

But this is balanced out by the benefits, he adds.

“The workload for us and our staff is so much smaller in the spring. It goes without saying that calving 500 cows in the spring compared to calving 500 cows and 120 heifers makes the job easier.’’