Dairy Advice - Spring

The importance of Peak Milk

Improving your herd’s peak milk production levels will go a long way to lift the potential production for the whole season. Find out why nutrition should be your first target.

Some eight to ten weeks after calving is arguably the most important time in a cow’s lactation. Up until then, her milk production will have steadily climbed to reach peak milk.

While the remaining lactation sees the actual volume taper off from this point, the relevance of the peak milk volume remains a defining factor. It is widely regarded as a benchmark indicator for her overall success for the season. In other words: higher peak milk production levels increase the total potential production for the season.

Lifting the peak and the season’s performance

So what’s involved in optimising the early season performance?

First of all, it’s important to consider the underlying physiological challenges: Remember that as the cow approaches peak milk, her body has undergone major changes that have put tremendous stress on her metabolism. After growing a foetus, she is launching into milk production which drives her tremendous energy demands. However, as her rumen is still expanding (while her uterus retracts post-calving) it’s physically impossible for her to consume enough to meet her elevated energy demands.

It’s a textbook case for targeted nutritional support in order to reduce liveweight losses and boost performance.

But to achieve a successful outcome, it’s necessary to adopt a dual objective, with a focus on quantity as well as quality of feed.

Ensuring adequate quantity

Herd feed intakes should aim towards the potential of 4% of liveweight; 18kg DM/cow/day for a typical 450kg LWT. However, this is a ‘down the throat’ target and should allow for utilisation problems, residuals and wastage of any supplementary feeds.

If using supplements, ensuring there is sufficient feeding area (700mm feedpad space per cow), bin space or trolley access will help all animals get their share of pasture and supplements.

For forages and crops, enforcing even feed distribution shouldn’t be overlooked. In terms of pasture it can be addressed by releasing the entire herd at once to ensure all animals graze the pasture evenly (rather than allowing the first cows to eat all the grass). Similarly it pays to look out for heifers or shy cows that may end up being underfed. They easily fall victim to bullies and become too weak to push for their share of the feed. They are particularly susceptible to energy deficits which invariably impacts on lactation and mating performance.

Nothing beats quality of nutrition

To lift production levels and reduce liveweight losses the diet should reflect two main quality hallmarks:

  • Increased energy density
  • Elimination of limiting nutrients

A feed option with a higher dry matter content and less fibrous matter (e.g. high quality pellet at 88%DM, grain or cereal silage at 33% DM) is vastly superior to pasture (at 10 – 12% DM) in its ability to increase herd intakes.

A herbage test will reliably identify any limiting nutrients which can then be effectively addressed with supplements.

As a general rule, spring pasture will typically deliver high available protein (30% compared to 18% required by the cow) with low soluble carbohydrates (5 – 15% compared to ideal levels of 30%, and a minimum of 10%).

Complementing the pasture with a soluble carbohydrate source is generally a good option to lift diet quality, and drive up herd production levels when dietary protein levels are high. 

Several minerals and trace elements typically also show up as being deficient in spring pasture, specifically magnesium and calcium. These should be addressed as a matter of priority as they have a dramatic impact on animal health, reproduction and production.

In essence: any nutritional efforts at this time will reward you throughout the season as every additional litre produced at peak milk is expected to generate 200 litres for the remainder of the season.