Rolling, Cracking & Chopping.

Is it worth the effort?

A common question is - how much will I lose if I don’t process the cereal grain that I’m going to feed to my stock?

That’s a tricky question to answer!

It could vary from not much (if you’re feeding low amounts of cereal grain combined with lots of hay) to plenty (if you’re feeding high volumes of cereat grain with little roughage).

Rolling, crimping and grinding are all methods used to break the outer tissues of the grain and allow access of the rumen microorganisms and digestive enzymes.  Heating grain in addition to rolling or crushing causes gelatinisation of starch and increases susceptibility to microbial attack in the rumen and enzymatic action on the intestine.  This is why most professional feedlotters steam flake barley, for example.

Many reports exist on the use of grains in mixed diets containing about 50% forage. Rolling barley has usually led to an increase in digestibility and almost doubled starch digestibility to 99% (Toland, 1976; Morgan and Campling, 1978a).

In another study, the digestibility of the unprocessed barley was as low as 27% (Nordin and Campling, 1976).   Rolling the barley improved starch digestibility for cows (71.4% vs. 23.3% for rolled vs. whole, respectively).

There was no significant increase in starch digestibility however for calves with only a 14% increase (whole grain: 74% digestibility, rolled 87% digestibility). This means that processing grains is far more economically viable for cows than for calves. 

In a 1996 study, by Mathison et al, the digestibility of whole barley grain was 16% lower than that of processed grain.  Rates of live weight gain were reduced by 5-50% when barley was unprocessed, and feed required for gain was increased by 15% to 100%.

Whole wheat is a small, hard grain that is typically of low digestibility in mixed diets eaten by beef cattle.  Digestibility of around 60% was reported by Toland (1978a) and Kimberley (1976) and after rolling or crushing digestibility improved to 86% (Toland, 1978a), giving us again an overall increase in digestibility of 26%.

So in summary, yes it’s a good idea to process cereal and pulse grains, for cattle.

There is no advantage to processing cereal or pulse grains for sheep, in terms of digestibility, however there is a major advantage in matching the mixed grains particle sizes in order to stop sheep sorting the grain.  

Practically, this might mean that you feed whole barley and a cracked/rolled lupin to sheep.

A roller mill will give you a grain that has had it’s outside seed coating cracked and is available to the rumen microbes yet is still intact enough to pose a low acidosis risk.

A hammer mill on the other hand can crush the grains to powder making them a higher acidosis risk. It can also result in varied grain particle sizes which won’t worry cattle but can increase the sorting ability of sheep.

While you’re considering upgrading your livestock feeding equipment, consider a mixer.  Feeding a total mixed ration including hay and grains allows you to completely control intakes and minimise the risk of acidosis. You can typically achieve better weight gains with a TMR than with grain and hay separate.  Additionally, it can save you money because cows sure do like to overindulge on hay in racks, costing you money, and sheep sure do like to indulge in far too much grain on any random day, causing deaths!  Feeding a total mixed ration usually has to occur once or twice daily though, so it is worth considering this constant daily labour input.

Of course, feeding livestock is not for everyone and you might instead choose to sell rather than feed.  Whatever course of action you decide upon, it’s a good idea to make a plan and act early.

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This information is the intellectual property of Animal Health & Nutrition Pty Ltd. No part of this work may otherwise be reproduced or copied in any form without the written permission of Animal Health & Nutrition Pty Ltd. The information is intended to be general in nature and you should seek information tailored to your situation and enterprise before making decisions.