Better rumen a beef opportunity

“Setting up the rumen in an animal is the cheapest influence you can have on feed efficiency,” Jack Tarrant of local ruminant nutrition business Animal Logic told the field day hosted by Focus Genetics on Rissington Station.

“The feed wedge and other things pay for themselves, but the fact that you have an animal with a rumen environment that is capable of being 25-30% more efficient for the lifetime of that animal is a really big thing.”

The rumen is part of a ruminant’s four-chambered stomach. It’s sometimes referred to as the animal’s ‘fermentation vat’ but when a calf is born, it’s only the size of a walnut, explains Tarrant.

Yet later in life, 80% of the animal’s protein and energy will be derived from the by-products of fermentation in the rumen and the better developed the rumen is, the more efficient the animal will be.

During a calf’s first few months the rumen starts to develop as it starts to try feeds other than milk. Up to about six months old management of the calf can influence that development, but after that the window of opportunity closes.

Tarrant says research shows milk suppresses rumen development and that early weaning, within reason, is beneficial.

“If you’ve still got calves on cows at five-and-a-half months, you are actually limiting the development of the rumen,” he points out.

“Weaning time is the best opportunity to fire up the rumen because you can influence the size, wall thickness, vascular development, surface area and how active it is for its whole life.”

A diet higher in starch rather than protein is beneficial.

“How well you wean calves… is going to dictate what that animal will do for the rest of its life. If it’s done poorly, you set the ceiling for how effectively that animal will convert feed into production for [ever].”

The catch is high starch feeds can be dangerous to calf health if introduced suddenly or in excess. Tarrant says Animal Logic’s products, such as Weanermax Pellet and ReplenX, allow safe feeding of starch and help maximise rumen development. 

But do such feeds stack up financially?

“What we’ve found in New Zealand and especially on the dry east coast, is we’ve been able to take calves off the cows 2-3 months earlier than usual. It means farmers can go back to using their cow as a cow again.

“On properties with high sheep stocking rates they can get those cows in to tidy up pasture. If you still have calves on cows, then there is a cost to doing that in terms of calf growth rate.  You can also prioritise feeding your calves on some of your better pasture.”

In Australia, Tarrant says they’ve increased stocking rates across whole farms “just using this one protocol”.