Sending heifers on “work experience” in the milking system before they calve and thinking about how they are introduced to the herd is vital to ensure they survive and thrive, according to veterinary nutrition consultant, Richard Cooper of Evidence Group.

Speaking at a recent AHDB Dairy Calf to Calving event, he said training and adaptation played a crucial role in helping to limit reductions in dry matter intakes around calving and reduced the likelihood of metabolic issues and dips in production.

“Cows and heifers naturally drop their dry matter intakes around calving and go into negative energy balance in early lactation where demand for energy exceeds supply, but it’s the extent of that gap that causes problems. If negative energy balance goes on for too long or is too deep, too much body fat is mobilised. This can lead to fatty liver, which results in poor immune function, reduced production and increased risk of issues like retained foetal membranes and poor fertility,” he said.

Around 25% of cows and heifers experienced fatty liver around calving. To avoid this, taking steps to maximise dry matter intakes was vital. Mr Cooper said one way to do this was to think about how heifers were mixed with the herd post calving.

He made reference to one herd which had housed heifers and cows separately at calving and then mixed them in accommodation at relatively high stocking densities. They had then witnessed a 40% drop in heifer yields - or 10 litres a day. This was due in part to reduced dry matter intakes as a result of competition at the feed barrier. In comparison, cows largely maintained yields, only drooping by about 1 litre a cow.

In an ideal world Mr Cooper advised running heifers in a separate group in their first lactation and introducing them to cows in their second lactation. This would give them time to understand the system and grow. However, where system set-up did not allow this, mixing pre-calved heifers with cows 6-8 weeks before they calved could be an option, or having a fresh-cow and heifer group.

A trial carried out by Hillsborough found that heifers that were mixed with dry cows three weeks before calving received lower levels of aggression when introduced into the milking group post calving, compared to heifers that weren’t pre-mixed.

When introducing heifers into the main herd, Mr Cooper advised moving them in groups, preferably in the evening when sheds were quieter. This fitted with AHDB Dairy research which showed heifers coped better with weaning when housed in pairs from day five of life, versus being housed alone.

Mr Cooper also emphasises the importance of not over-stocking sheds when introducing heifers into the main herd. “Aim to stock at 90-95% stocking rate or lower so there’s a few extra cubicles so heifers can get away from cows. And also provide more generous feed space - aspire to give heifers in the transition group and milking herd 80cm of trough space,” he said.

He also suggested training heifers to cubicles and locking yokes and running them through the parlour in advance.

“I think adaptation to adult life and going on work experience is important. Heifers should have seen the milking parlour before calving. Anything that can ease transition into adult life will pay itself back in terms of how they perform and last in the herd,” he said.

>> As part of AHDB Dairy’s Calf to Calving initiative, the growth, health and nutrition of 10 heifers on each of 13 farms across the country are being monitored every three months. Farmer meetings are also being run on the host farms with the aim of bringing the latest research and best practice to farmers, improving calf survival and increasing the number of heifers making it into first lactation.

Find out more at: http://www.dairy.ahdb.org.uk/c2c