While there is a far higher understanding of the role of principal nutrients in transition cow diets, increasingly close focus must also be placed on micro-nutrients and energy sources to optimise the efficiency of transition, according to Mike Chown from UFAC-UK.

He says transition cows are expected to achieve an enormous amount in a very short time without falling sick.

“They've got to calve down safely and recover from the stresses of parturition. Then, within a short time frame we expect them to start eating significantly more to support the rapid increase in nutrient demand for milk production. We need them to do all of this without suffering any metabolic disorders along the way."

Mr Chown said poor transition cow management can result in significant economic losses to include udder oedema, milk fever, retained placenta, displaced abomasum, laminitis, metritis, ketosis and fatty liver syndrome which all result in reduced profitability.

The challenges for high yielders are just as great. Maintaining high production of quality milk, without losing body condition, getting back in calf and staying healthy all cause significant metabolic stress.

“The best we can do is make sure the diet is supplying all the nutrient requirements. Successful transition cow management is about minimising stress and providing a fine-tuned balance of nutrients,” he said.

Although farmers may know a lot more about the headline objectives of transition diets such as promoting dry matter intakes of around 12-14kgDM/day, maintaining good rumen fill and avoiding high calcium feeds, there is still scope to improve transition cow diets.

He also encouraged producers to look closely at the specific nutrient requirements around transition period, particularly with regard to energy, where there might be opportunities to boost the cow’s prospects.

“Early lactation cows have a high demand for glucose which accounts for around 70% of their energy needs. Glucose drives milk production but is also vital as the fuel for the immune system function in the event of a disease challenge.

"To optimise total glucose supply, consider feeding dry cows nearing parturition a source of rumen-inert glycerine which is the most efficient source for glucose production by the liver. Feeding glycerine together with rumen-inert choline will help maximise liver efficiency.”

Mr Chown said that it is important to maximise the availability of glucose for milk production and minimise partition to other unproductive uses. For example, the cow’s ability to fight infections quickly and efficiently during transition is vital. This can be achieved by ensuring the diet contains sufficient vitamin E and selenium to help reduce oxidative stress and lessen the consequence of infection.

“Omega 3 fatty acids in particular EPA and DHA from the most effective marine sources also strengthen the overall immune response. With a robust immune system glucose is spared from fighting infection to maintain milk production.”

To support glucose metabolism he advises feeding a balanced supply of highly digestible rumen-inert fatty acids to boost energy density of the diet and help reduce body condition loss.

“The Omega 3 fatty acids also play an important role in fertility, increasing the size and quality of eggs, leading to improved conception rates and reducing early embryonic deaths. They can make a big difference to how quickly cows get back in calf again and reduce the risk of culling.”

Finally he says cows need a supply of essential amino acids. If any essential amino acid is limiting the consequence is yield depression, reduced milk protein, compromised fertility and poor health. In most transition diets the supply of methionine is most critical. Mr Chown advises supplementing the diet with methionine in a highly effective rumen-inert form.

“Fine-tuning the diet will help cows transition effectively, doing all that is expected of them while making high yielding cows better equipped for the challenges they face.”