Increasing Cow/Calf Profitability Using Chaff and Chaff/Straw Feedstuffs

Over the years, many cost-conscious cow/calf producers across western Canada have recognized the potential for chaff residues to help reduce the winter feeding costs in mixed farm operations.

Chaff that has often been considered a nuisance on the grain side of a mixed farm can prove to be a valuable low cost feed alternative on the cattle side. In fact, chaff may prove to work as a win-win solution for both operations, if some basic steps are followed. And nothing is more important than to first recognize that chaff is a low quality feed, suitable only for mature beef cows.

What is Chaff?

Chaff is made up of glumes, hulls, unthreshed heads, short straw, leaf material, weed seeds and whole or cracked kernels from the harvested crop. As a result, chaff has a higher nutritive value than straw.

Background

Collection, handling and feeding
Chaff can be handled and collected in either of two ways. It can be collected and dropped on top of the straw swath, where it can then be baled using a cyclone type of attachment, or it can be collected and blown into a chaff wagon using a chaff collector. The wagon then dumps piles of chaff in the field for later collection or field feeding.

The first method of collection and handling is easy and requires a minimum of equipment purchases or modifications. Once baled, the chaff can be fed in round bale feeders, rolled out in the field, or tub ground and mixed with other feeds.

Chaff piles left in the field may be grazed or moved to a central feed pile and fed. Field grazing of chaff is relatively inexpensive, efficient and effective. Electric fencing may be used to limit access to chaff piles.

Field feeding is preferable to corral feeding because little if any yardage is taken up with the field-feeding scenario. Corral feeding may also prove more expensive simply because there is a transportation cost associated with removing the chaff from the field. One issue with field feeding is the potential for the development of small thick mats of straw around field feeding sites. These areas may suffer from poor germination and weed infestations in the following year.

If yard feeding is preferred, most chaff piles can be collected using a forage harvester or a hay sweep on a front end loader. (This feeding method also removes weed seeds from the field.) Once in the feed yard, the chaff can be mixed with other feeds, or it can be piled and fed free-choice. An electric wire may be used to limit access to the chaff pile.

The advantages of mixing chaff with silage are that producers are better able to stretch their feed resources and better match the feed to animal requirements. Transportation is the biggest issue concerning the economics of chaff. Chaff is very light but very bulky, which makes it costly to move long distances.

Feed Testing

Why feed test?
As shown in Table 1, chaff quality can vary. The major factors that influence quality are crop type, stage of maturity, weed content, method of harvest, combine settings and crop and field variability. Chaff from oats and barley generally has a higher nutritive value than wheat, pea or canola chaff. As a result, it is important to use feed testing to determine feed value.

Feed sampling procedures
Use a core sampler to get samples from baled straw with chaff. For round bales, take about 20 samples from different bales. Sample from the round surfaces of the bales at a variety of locations. For rectangular bales, take 1 sample per bale from at least 20 bales. Take the samples from the middle of each bale end. Place the samples directly into a plastic sample bag.

Chaff piles can most easily be sampled by hand (Figure 1). Take at least 20 samples from a variety of different piles at different locations and depths to obtain a representative sample. Place these samples on a smooth surface and mix. Divide the sample to obtain a sub-sample sufficient to fill a standard forage sample bag (about 2 liters).


Figure 1. Chaff pile

Special care should be taken to ensure the sample is representative; heavier and lighter chaff components must be adequately represented. Ask that the feed testing laboratory grind the entire sample to ensure that the sample is representative of the original chaff.

What to test for
Feed laboratories offer many different analysis packages. The test or tests you choose will depend on your own needs and budget. Most packages of analyses include levels of crude protein, acid detergent fibre (ADF), neutral detergent fibre (NDF), calcium and phosphorus. The laboratory will use this information to estimate energy levels for you. You may also wish to test for trace minerals levels at least once every two or three years to assess the adequacy of your trace mineral supplement program.

Two methods of feed testing are available to beef producers. The wet chemistry test consists of simple chemical analysis. Near Infrared Spectrometry or NIRA method uses light wave analysis. Unfortunately, the NIRA test uses localized databases (different growing conditions than your own). In addition, most of the feeds tested are of high quality, so feed quality estimations of low quality feeds are often inaccurate. Although the wet chemistry analysis is more costly, it is considered to be the more accurate method of testing chaff.

Using feed test results
To meet livestock nutrient requirements, chaff/straw rations will generally require some supplementation for protein, energy, minerals and vitamins. Software such as Cowbytes provides a quick method to properly balance nutrients in chaff/straw feeding systems. Further information on Cowbytes can be located on Alberta Agriculture’s website Ropin’ the Web.

Feeding Chaff

Quality variability in chaff
Several variables can affect chaff feed quality:

• Combine settings: The more grain in the chaff, the better its feeding quality. If there are a large number of small kernels in the sample, the combine can be set to throw the light kernels over to the chaff, thereby improving the quality of the chaff. If the sample contains more broken straw than bits of grain and leaf material, it will have a lower feed value.
• Combine efficiency: The poorer the efficiency, the more cracked grain and unthreshed heads that will pass over the sieves and into the chaff.
• Underseeding: Underseeded crops such as alfalfa add green leaf material to the chaff, increasing crude protein levels.
• Stubble height: Higher cutting heights such as with direct combining can produce straw with higher nutritive values than when cut at ground level. Although this approach will reduce total straw yield, it will help in improving the overall quality of the chaff sample.

• Use protein supplements in chaff/straw combinations when chaff crude contains less than 6 per cent crude protein. Protein supplementation will enhance the digestion of low quality roughage.
• Adjust ration supplementation during winter feeding. For mature pregnant animals both protein and energy requirements increase during the second and third trimester.
• Protein sources such as lick tanks that contain high quantities of non-protein nitrogen are not as effective as natural protein sources when supplementing low quality forages.
• Plant-based supplements such as canola meal or alfalfa hay are a more effective form of protein supplementation. However, supplements such as canola meal require mixing with other feeds to achieve adequate feed intake.
• Concentrate supplements can be used to supply protein (15% crude protein or greater) and energy (75% TDN or greater). Mixing with other feeds may be required to achieve required feed intake.
• Supplemental minerals, salt and vitamins need to be provided when chaff/straw rations are fed.

	Ration #1 lbs	Ration #2 lbs	Ration #3 lbs	Ration #4 lbs
Barley chaff (In field)	25	22	25	25
Alfalfa hay	8	–	–	–
Barley silage	–	–	20	–
Barley grain	–	9	–	–
20% protein pellet **	–	–	–	5
Mineral/vitamin/salt	0.1	0.1	0.1	0.05

Acres/Cow/Month	=	30 lbs chaff/day x 30 days
		600lbs chaff x 80% (20% waste)
	=	1.9 acres/cow

Crop	Soil zone	Pounds of straw per bushel of grain*	Pounds of chaff per bushel of grain**
HRS Wheat	Brown	50	20 - 25
	Dark Brown	65
	Black	80
CPS Wheat	Brown	40	20 - 25
	Dark Brown	50
	Black	60
Barley	Brown	30	5 - 10
	Dark Brown	35
	Black	45
Oats	Brown	30	5 - 10
	Dark Brown	35
	Black	45
Canola	Brown	40	15 - 20
	Dark Brown	50
	Black	60
Peas	Brown	40	20 - 25
	Dark Brown	50
	Black	60

	$/cow/day
	In-field chaff	Drylot
Chaff ($5.70/ton)	0.09	–
Grass/legume hay ($60/ton)	–	0.9
20 % protein pellet ($170/ton)	0.42	–
Feed delivery/yardage *	0.1	0.67
Feeding management (electric fence/labor)	0.15	–
Total	0.76	1.57
Net advantage	0.81