Milk records can be an untapped source of insight into the nutritional requirements of dairy cows, particularly during the first few weeks of lactation. Producers are therefore being encouraged to utilise milk lactose levels to help predict negative energy balance, manage nutrition, and optimise performance.
Energy deficits in lactating cows are often only identified once milk volume drops or noticeable changes in body condition are seen. Independent nutritionist, Andrew Jones, explains how milk producers can use records to prevent setbacks and inform decisions about ration composition.
“Dairy cows have varying nutritional requirements throughout lactation but undoubtedly they’re at the highest during the first few weeks after calving,” says Andrew.
“Meeting these demands can be difficult and if diets don’t contain enough energy, cows will have a negative energy balance. It’s at this this point that requirements for maintenance and lactation exceed dietary intake, altering the cow’s metabolic state, resulting in her not having sufficient nutrients to support both yield and metabolic health,” he adds.
Using milk records to assess lactose levels
For this reason, he advises that producers use their milk records to assess cow energy levels before physical changes are observed.
“Milk lactose levels indicate if a cow’s glucogenic energy requirements are being met sufficiently.
“Farmers with high yielding Holstein cows should be aiming for lactose levels above 4.55% (4.65% in Jerseys). If they’re below this level it is likely that cows could be under performing due to an energy deficit, and rations will then need balancing to raise overall energy levels,” says Andrew.
He advises that it is particularly important to check milk records four to six weeks after calving, as at this point in lactation milk production increases faster than energy intake.
Increasing dry matter intakes
Alongside monitoring lactose levels, Rob Fowkes, from Quality Liquid Feeds, explains it’s also essential to manage the dry matter intakes of transition cows, to enable optimum performance.
“Early lactation cows are especially prone to acidosis, due to depressed intakes around the time of calving, coupled with the rapid increase in diet fermentability as cows transition from dry to lactation diets,” says Rob.
Rob therefore advises that diets should focus on delivering correct energy requirements whilst maintaining a stable rumen pH to put cows in the best possible position to utilise energy to maintain production and their health status.
“Feeding an energy-rich feed, such as QLF’s molasses based liquid feed, at between 5-7% of a cow’s DMI can help to achieve optimal microbial protein production,” he says.
“The glucogenic supply from the six carbon sugars found in molasses help to condition the liver and increase milk production. And by providing sufficient levels of glucogenic energy in the ration, insulin levels are increased, and fat mobilisation decreased.
“This helps to maintain body condition and rumen pH, creating a more efficient rumen environment, resulting in increased fibre digestion and improved forage intakes.
“And, as well as offering a source of energy for efficient rumen processing, the addition of liquid sugar also increases the palatability of the ration which can reduce sorting and increase DMI,” says Rob.
Andrew reminds producers that when changing diets, it’s important to do so gradually to ensure the rumen environment remains stable which helps to improve DMI post calving and reduce risk of acidosis. Any changes in diet can take two to three weeks to change the rumen flora and fauna.
“Three-weeks prior to calving, rations should include an increased supply of energy to compensate for the lower DMI experienced immediately after calving,” says Andrew.
“Providing sufficient levels of glucogenic energy, in the form of molasses, will enable this and prevent excessive mobilisation of body fat, which can lead to conditions such as ketosis and fatty liver.”
He adds that producers can check lactose levels using milk records. Utilising these resources can be a vital tool in informing producers about necessary dietary changes to optimise performance and will provide them with invaluable insight into how cows are responding to both dry cow and lactation rations.
Top tips to avoid negative energy balance
- Analyse silage every four weeks and adjust ration accordingly
- Check body condition scores throughout lactation cycle
- Manage dry cow nutrition
- Check lactose levels to identify energy deficits