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But getting high-quality bedding in May when it was 106ºF in places like Arizona proved difficult. It’s now August, and the summer heat is stuck on high – that means bacterial, fly and tick issues both in and out of the barn. But not everyone has a sand pit (inorganic bedding) to dig into, and quality straw (organic bedding) has been hard to find. What locally sourced vegetation can we use as alternative bedding?
What makes good bedding material for cows?
Key attributions for any bedding material are (a) suitability for udder and respiratory health, (b) durability after eight to 16 hours of cow naps a day, seven days a week and (c) heating resiliency as moisture accumulates and biological activity fluctuates in seasonal temperatures (Figure 1).
In June, researchers at the department of agricultural engineering, Federal University of Lavras in Minas Gerais, Brazil, published a timely article in the Journal of Dairy Science on, “Properties of conventional and alternative bedding materials for dairy cattle.” Their study compares analyses of water-holding capacity, moisture content, porosity, bulk density, bacterial composition and carbon-to-nitrogen ratio of 17 bedding materials in use in Italy, Slovenia and the Netherlands. In a nut shell (they did not test peanuts), they compared traditional grain husks and grain crop straw (barley, triticale, wheat) to conifer and hardwood sawdust, bark and woodchips; and locally available alternatives like hemp, flax, miscanthus, spelt and an underwater grass Posidonia oceanica. Each was ranked for suitability in compost-bedding packs or freestall stanchions. The study is a good example of what to look for when considering bedding materials for cattle.
In this article, we look at three alternative bedding options: the old standby “hay barn chaff,” hemp straw and one hardwood that is locally abundant.
Alternative bedding questions to ask:
- Is it nontoxic to cattle?
- Can it absorb moisture while keeping cattle dry and not irritate skin or mucous membranes; if ingested, will it not cause harm (respiratory, circulatory, gastrointestinal and ambulatory)?
- What is its:
o Water-holding capacity
o Moisture content
o Porosity
o Bulk density
o Bacterial composition
o Nitrogen
o Organic matter analysis
o Carbon-to-nitrogen ratio
Husks: Hulled grains and peanuts have desirable bedding qualities, but total coliform counts in husks and seasonal molds can be 700,000 times higher than for wood shavings and straw, even before manure accumulates. Mike Maroney, DVM, Wisconsin, talks about coliform mastitis in his “Milk money fact sheet #4.” “Coliform bacteria are normal inhabitants of soil, digestive tract and manure. They accumulate and multiply in contaminated bedding. Coliform numbers of 1,000,000 or more per gram of bedding increase the likelihood of an udder infection and clinical mastitis.”
Hay chaff: In a fact sheet on moldy hay, forage experts from University of Wisconsin, Penn State, Michigan State, University of Idaho, North Carolina State and Kemin AgriFoods North America highlight seven molds commonly found in windrows that find their way into barn chaff. “Molds commonly found in hay include alternaria, aspergillus, cladosporum, fusarium, mucor, penicillium and rhizopus. These molds can produce spores that cause respiratory problems, especially in horses or other animals fed in poorly ventilated areas and, under some conditions, will produce mycotoxins.” While hay chaff has a lot of attributions that make it structurally useful as bedding material and a carbon-to-nitrogen ratio of around 25-1, the reality is this: Hay chaff has been chewed on and deficated on by microorganisms, molds, birds, rodents and vermin which can be a significant source of mastitis-causing bacteria.
Hemp: The fiber from this 12,000-year-old plant has gone from around 9,000 acres in the U.S. in 2016 to over 400,000 acres in 2020. Hemp fiber has a lot of positives as a bedding alternative. Hemp’s carbon-to-nitrogen ratio (98-1) is lower than other straw sources but not statistically different. Hemp is nontoxic to cattle, and baled hemp in storage is field-dried or dryer-cured to moistures below 10%. However, state regulators under the federal research permit may not have considered bedding as a viable method of “destruction” of the crop or legal transport of the crop. But it could be. Just remember to differentiate between clean hemp and hemp left lying in the windrow. When hemp or any straw begins to rot, dark flecks of fungal colonies will begin to appear in the stalks. The most frequently occurring fungi found in hemp residue are “alternaria, hormodendrum, fusarium, cephalosporium, phoma and Trichothecium roseum.”
White ash: The U.S. forest composition of 8 billion ash trees mixed in with other hardwoods is not much different than when Grandpa cut his own timber and used the shavings for bedding his “mulch cows.” The sheer volume of dying ash still standing along roadsides and in hedgerows from emerald ash borer creates a locally sources supply of an alternative bedding. However, carbon-to-nitrogen ratios are quite high in hardwood materials: over 100 for bark mulch to over 500 for fresh sawdust. Wood products with a carbon-to-nitrogen ratio over 25-1 to 30-1 will result in free ammonia escaping the bedding pack, so ideally, we want a bedding material closer to but not below this value so the microbes can work in a stress-free environment. Wood shavings have a higher water-holding capacity than say, dried sawdust and bark mulch, and are comparable to barley straw. Chipped hardwoods range from 25% to 50% moisture with a typical analysis of 42% before air (12% to 20%) or kiln (7%) drying.
And, ash bore is not toxic to cattle. In fact, most hardwood products except cherry and walnut can be made into bedding materials and are comparable to straws for low levels of E. coli and klebsiella spp. growths. Ash wood could even have insecticidal repellent qualities according to a mention in a USDA 1991 forestry publication.
Harvesting trees that are damaged or dying for bedding material quality is not a priority for the timber industry nor is harvesting small pockets of dead ash on roadsides, right of ways and hedgerows. But it could be. Municipalities in high-urban-density areas continue to look for an alternative market for ash wood chips and shavings coming from residential areas as power plants shift away from biomass fuels to lower priced petroleum. In the wake of an unprecedented amount of stimulus money and rainy day gas industry funds set aside for economic development, cleaning up these road and utility corridor hazards might be a win-win for stimulating the local workforce to work in an outdoor environment.
Lastly, the dual value of hardwood ash as a liming material is well known. University of California evaluated the agriculture use of wood ash in a 1999 publication. “Wood ash is an effective liming material because the calcium magnesium and potassium oxides in ash can neutralize the acidity in soils.”
