Fibre factor critical right now in beef cattle diets in the south

Stalky hay and poor quality silage is now being fed out as a result of the inability to cut at the ideal time during prolonged wet periods last spring.

It's affecting producers across most regions of Victoria, into the Riverina and in some south eastern parts of South Australia, government extension officers report.

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Agriculture Victoria regional manager Brett Davidson, based at Tatura, said some very poor quality feed tests on conserved feed were now coming through.

"The feedback we are getting is cattle just aren't putting on weight like they normally would," Mr Davidson said.

"They can't physically eat enough of the hay this year because the neutral detergent fibre - or NDF - is too high. The feed is effectively too rank."

Mr Davidson and RSPCA Victoria's Rachael Laukart addressed the issue in a webinar on keeping cattle healthy held last week.

They explained an NDF content range of between 30 and 50 per cent of the feed was ideal but this year some feed tests were returning readings into the 60 per cent range.

"In a wet year, plants need to hold up a big seed head and so need a strong stem to do that, therefor all the energy goes into making a strong stem," Mr Davidson explained.

"That explains why hay quality is usually quite good in drought - there's just not enough of it."

To compensate, producers need to be adding energy and protein sources to diets.

For growing stock, the recommendations are 10pc metabolisable energy, 15pc protein and 30-50pc NDF.

Other factors to watch include ensuring the fibre length is muzzle width - this is where it's most effective.

"The key is to feed test, feed test, feed test - know what you are buying and what you are putting out," Mr Davidson said.

Ms Laukart said one way of considering feed quality was in terms of how much it allows an average cow to eat.

"So if we are in the position of not having a lot of grass ahead of us now and we're feeding out a poor quality hay due to the wet spring, with a feed test of 75pc NDF, a 500 kilogram cow can only eat up to 8kg a day," she said.

"The reality is that animal will be losing condition even though she is full as she is just not getting enough energy and protein.

"If we move into a hay with a 65pc NDF, the cow will eat another 1.2kg a day which means she should maintain her condition.

"But if we can get into the range of 45pc NDF, she can eat up to 13kg of dry matter per day and will be gaining weight. That's the difference it makes."

Another point is that research shows as much as 30pc of feed can be wasted by not feeding it out properly.

"If you are using a hay feeder, head spacing for cows must be adequate," Mr Davidson said.

"If there is not enough head space, the animals will drag hay out and half of it drops on the ground."

Introducing grain is a great source of energy and protein but it has to be done slowly, the advisors said.

"Introduce small amounts - little bits a couple of times a day to allow the rumen to set itself up," Mr Davidson said.

The grain change should ideally be around half to 1kg a day over one to two weeks.

"What that means is you have to be prepared for the fact that if you go down that track it takes time to build the animal up to reasonable intakes," Ms Laukart said.