By Debbie James

Dedicated housing for managing cows during the transition period has improved post-calving cow health at a Welsh dairy farm.

John and Anna Booth invested in the new facility at Rhual Dairy, an AHDB Strategic Dairy Farm, near Mold, in 2018, replacing a system had that only had sufficient space for managing cows on a transition ration for up to two weeks.

“We were getting everything else right but we couldn’t get the cow transition right, we were always short of space,’’ John told farmers attending an AHDB open day at Rhual Dairy.

The new shed has capacity to house dry cows for four weeks.

“It is still early days to see the full results of the benefits, we won’t get that until the end of the lactation, but the early signs are looking really good,’’ John reported.

“Cows are calving down a lot easier, they are cleaner and we are getting more or less no cases of milk fever.’’

The Booths, who run an all-year round (AYR) calving herd of 336 Holstein Friesians, have also invested in a new diet mixer which chops straw to the short length required in the transition ration.

“That is doing a much better job than our old wagon so, although the base of the ration is much the same, it’s the processing of it that has changed. The diet is more consistent and we are seeing higher intakes on that,’’ John said.

The dry cow ration at Rhual, formulated to deliver 120 megajoules (MJ) of energy is made up of 18kg third cut silage, 6kg haylage bales, 6kg maize silage, 3.5kg chopped straw, 2kg protein blend and 0.150kg dry cow minerals.

Since the changes were put in place, cases of retained foetal membranes are down to 2 per cent, left displaced abomasums to 1 per cent and milk fever to less than 1 per cent.

Careful management of the transition period is crucial to secure milk yields, fertility and profitability in the following lactation.

At the open day, facilitated by Samantha Alexander, AHDB knowledge exchange manager (dairy), farmers were advised to consider the dry period as the start of the next lactation, not the end of the last one.

Phil Clarke of P&L Agri Consulting Ltd, described the dry period as the single most important phase of production.

He recommends a dry period no shorter than six weeks – briefer than this and profits will decrease, he warned.

Cows need to develop a good appetite and rumen capacity in the close-to-calving period.

Maximise trough space – ideally 90cm/cow.

Target 40-45 per cent dry matter (DM) in the diet – add liquid to the ration if it is higher than this. Aim for a DM intake of 12-14kg, Mr Clarke advised.

He recommends an energy intake of 115/120MJ/cow/day and 13-5-15.5 protein.

Mr Clarke described potassium as a “killer’’ in dry cow diets. “Keep it as low as possible, make specific dry cow silage that hasn’t had slurry applied to it.’’

Magnesium to potassium ratio should be at a maximum of one to four – if the ratio is greater then add more magnesium to the ration.

Dry cow management extends beyond ration alone – these cows need plenty of room to move around to exercise and to build muscle strength; cow comfort must be exceptional and a good supply of clean water will encourage the cow to eat more.

Dr Mo Kemp, of Wern Vets, the farm vet at Rhual Dairy, who was also a speaker at the open day, advised farmers to monitor the energy levels of cows pre-calving by checking urine pH and ketone levels.

Maintain body condition score (BCS) at 2.5-3 – it should be the same at drying off as at calving.

Drying off should be a specific task, not a job done at the end of milking, and an exceptional level of cleanliness is vital.

“Use surgical spirit and cotton wool, not the wipes that come with the tubes, and allow the cows to stand for 30 minutes after drying off,’’ said Dr Kemp.

Inspect cows daily in the first week after drying off, she added.