As autumn calving approaches, dairy farmers are being advised to plan ahead to avoid costly metabolic disorders and unfulfilled milk yield potential in early lactation.

Ensuring sufficient feed intakes, monitoring body condition score and maintaining rumen pH should be key priorities according to Dr Colin Byrne, ruminant technical and deployment manager for Lallemand Animal Nutrition.

“A sub-optimal transition period can lead to metabolic issues such as milk fever and ketosis, as well as compromised rumen function. This can increase the risk of sub-acute ruminal acidosis and leaky gut,” he says.

Warning signs include milk yields remaining static or even falling over several days, liquid faeces containing bubbles, and poor rumen fill. The latter may be indicated by a pronounced hollow in the triangle just behind the ribs and below the lumber region on the cow’s left side.

Dr Byrne says inadequate feed space is one common pitfall leading to reduced feed intake during transition.

“Ideally, a minimum of 0.6m of feeding space per cow is recommended during the dry phase, to ensure she gets sufficient intake,” Dr Byrne says.

As the UK and Ireland has seen another summer of record-breaking temperatures, it’s worth noting that heat stress is also known to reduce feed intake and exacerbate the risk of oxidative stress during the transition phase. This can lead to increased somatic cell counts and reduced fertility.

“A high-quality mineral containing organic selenium, vitamin E and other antioxidants should be given during the dry phase and into lactation to reduce the risk of oxidative stress,” he says.

Dr Byrne also advises careful monitoring of body condition score (BCS) and planning ahead to optimise the length of the dry period.

“BCS should be 3.0-3.5 at calving – anything less will increase the risk of negative energy balance, and anything more will increase the risk of ketosis.”

A dry period of at least eight weeks is often recommended, but in some cases six weeks may be more suitable.

“For example, if the cow is well below a BCS of three 100 days before drying off, she may need more time to get into condition first. Or if she’s already fat at that point, she may be able to milk for longer before drying off, as she can afford to lose some body condition,” Dr Byrne explains.

Meanwhile, maintaining a stable rumen pH is an often overlooked but important factor.

“Sudden changes in diet can cause the pH to drop to 5.8 or even further. That’s when we start to get damage to the rumen wall,” says Dr Byrne.

Trials have shown adding a rumen-specific live yeast to the diet, such as Levucell SC, can support rumen integrity and stabilise rumen pH during the transition period.

“It’s best used as a preventative as it takes time for the rumen to adjust, so it should be added to the ration at least three weeks pre-calving and fed daily into lactation.

“Depending on the level of issues expected, up to double the dose can be fed during the transition period.”

Nutritional interventions can help support rumen health and comfort, but this should form part of a wider transition strategy that includes adequate feed space, careful body condition monitoring and good dry cow management, he concludes.