Cold temps mean using more bedding for calves

THERE are several factors that affect the amount of bedding needed for preweaned calves, including the amount of milk or milk replacer fed, weather conditions and bedding material characteristics.

According to Dr. Kevin Janni, professor and extension engineer at the University of Minnesota, understanding these factors and how they interact helps producers manage bedding for preweaned calves to enhance their comfort, health and growth.

Janni said there are 13 bedding factors to consider when selecting organic bedding:

1. Absorbency;

2. Availability;

3. Cost;

4. Water retention and evaporation rate;

5. Structure;

6. Structural integrity;

7. Handling;

8. Carbon content;

9. Carbon availability;

10. Animal health impacts;

11. Animal comfort;

12. Air quality impacts, and

13. Pathogen presence.

Availability and cost are typically the two main considerations for bedding, but Janni suggested that producers need to start thinking about other factors as well.

For example, he explained that absorbency or water holding capacity and structure are important, too. Carbon content and availability were included in the list for those who compost used bedding. If an operation's preweaning calf performance is not meeting the Dairy Calf & Heifer Assn.'s gold standards of preweaned calf health (Table), a reassessment of the calf management program should be considered.

In cold weather, deep, clean and dry bedding is recommended to keep calves clean, dry and insulated from cold and wet manure, floors and air. Bedding absorbs water and feces and becomes wet and soiled over time. Janni pointed out that clean, deep bedding allows calves to nest, which helps reduce heat loss to the environment by preventing their hair coat from becoming wet and matted. Bedding that can be fluffed and still retain its structure allows for more nesting.

"Roughly 80% of the water consumed by calves is returned to the calves' environment as urine, respiration and sweat," Janni explained. "Increasing the amount of milk or milk replacer fed will result in more urine added to the calf pen, and if calves produce more urine, producers need to use more bedding to absorb the urine if they want to provide a clean, dry place for calves to lie down."

Urine and spilled water cannot drain away if the calf barn has a concrete floor or packed earth. Some producers have floor drains or ground limestone under the bedding, but Janni said while those are both good ideas, they are not as effective because the bedding has to be extremely wet for liquid water to drain out of the bedding.

"Think of wet bedding like a wet towel," he explained. "The towel has to be extremely wet — too wet for good calf comfort — for water to drain out of it. You can wring out a wet towel to get water to drain out, but you still have a damp towel that is too wet to prevent wetting your skin."

Janni said another way to remove moisture from bedding is to evaporate it and remove it with ventilation air. The recommended winter ventilation rate is based on moisture control, so increasing the ventilation rate will remove the extra water by ventilation. Unfortunately, for ventilation to remove water or urine, Janni said the water has to be converted by evaporation from a liquid to a vapor, and to evaporate water, it needs to absorb energy to go from being a liquid to a vapor.

In hot weather, heat can come from warm animals or warm air. In warm and hot weather, ventilation air can dry wet bedding. In cold calf barns, however, Janni pointed out that the only energy sources are the calves, and they do not generate enough energy to evaporate water.

Janni said a presentation on natural grain drying by Ken Hellevang at North Dakota State University demonstrated how difficult it can be to dry things in cold weather. In the presentation, Hellevang pointed out that grain farmers do not use natural air drying when the air temperature gets near freezing.

Because natural air drying cannot happen in cold temperatures, Janni noted that wet bedding in dairy barns cannot be dried without adding heat, either. For grain drying, temperatures have to get back to 40 degrees F, or else supplemental heat is needed. For dairy producers, providing supplemental heat in calf barns is generally too expensive.

Agricultural Research Service (ARS) researchers recently reported on the water holding capacity of seven organic bedding materials commonly used in livestock facilities. The materials included corn stover, soybean stover, wheat straw, switchgrass, paper, corn cobs and three wood materials: green cedar, dry cedar and kiln-dried pine. They also used three different particle sizes: fine, medium and coarse.

The ARS results indicated that fine bedding materials held more moisture than medium or coarse materials. Unfortunately, fine materials do not fluff as well to help with nesting. Wheat straw and corn stover had the highest water holding capacity, while switchgrass and corn cobs had the lowest.

Janni said during cold weather, be sure to provide adequate clean and fresh warm milk, starter and water, but also be prepared to increase bedding use to maintain deep, clean, dry bedding, too.


Hawaii dairy

The total amount of locally produced milk in Hawaii is less than 9% of the state's entire market, and the rest must be imported from the continental U.S.

As part of its mission to increase local food production, Ulupono Initiative, a for-profit impact investment firm, is investing $17.5 million to form Hawaii Dairy Farms, a grass-fed dairy that will be located on the island of Kauai.

Based on the New Zealand pastoral dairy model that uses grass as the primary feed source, this dairy will bring together suppliers with best-in-class capabilities to create an operation that will infuse more local, fresh milk into Hawaii's dairy supply. The building permit applications have been filed, and construction is anticipated to start in 2014.

Hawaii Dairy Farms' operations will more than double local milk production, contributing an additional 11% to the statewide milk market. By drawing upon and adapting best practices from farm systems in both New Zealand and the U.S., Ulupono Initiative hopes to revitalize the dairy sector in Hawaii, where local dairies once produced all of the state's milk needs until 1984.

"After several years of studying the benefits of the grass-fed model to offset the volatile cost of imported feed, we believe that forming Hawaii Dairy Farms is an important step toward revitalizing our local dairy industry," said Kyle Datta, general partner of Ulupono Initiative. "This is integral to our mission to increase affordable and sustainable local food production."

Hawaii Dairy Farms will be located in the Mahaulepu area of Kauai on a 582-acre pasture parcel of Important Agricultural Land leased from Grove Farm. The overall design and construction are being done in partnership with Dairy SolutioNZ Ltd., a consortium of New Zealand's top dairy industry companies, as well as local business partners.


Wisconsin milk income

Wisconsin farmers didn't have their best year ever in 2013, but they were close, according to a new report.

Ed Jesse, University of Wisconsin-Madison professor emeritus of agricultural and applied economics, reported that Wisconsin farmers earned about $3.75 billion in total net farm income, $600 million more than in 2012 and just short of the record of $3.8 billion set in 2011.

Dairy farmers in the state generated a record $5.6 billion in milk sales due to a 1.7% boost in production and the second-highest average milk price ever.

Wisconsin's estimated 2013 milk production of 27.7 billion lb. set a new record for the fifth year in a row. Wisconsin's milk production has shown remarkable improvement since 2004, when the state reversed a 16-year decline in cow numbers. During 2013, the state added 3,000 cows, which contributed to the increase in milk production.

Jesse, editor of the annual "Status of Wisconsin Agriculture" report, said the overall financial performance of the state's farm sector reflected that of the dairy industry, which generates roughly half of the state's farm revenues.

Jesse suggested that the state's farm revenues and profits may decrease a bit in the year to come. Milk production is expected to increase because of cheaper feed prices in the U.S. and improved weather in Europe and New Zealand, which supplies most of the world's dairy exports.

The report's authors said average milk prices paid to Wisconsin farmers could drop as much as 5%. Additionally, Jesse said last year's huge harvests will weigh heavily on the corn and soybean markets.


Dairy Calf & Heifer Assn. gold standards of preweaned calf health (2011)

Performance indicator


24 hours to 60 days old

Mortality rate

Less than 5%

Scours (percent treated)

Less than 25%

Pneumonia (percent treated)

Less than 10%

Growth rate

Double birth weight

Colostrum management


15% of bodyweight within first 2 hours

Bacteria count

Less than 100,000 CFU/mL

Other attributes

Free of disease, blood, debris and mastitis


Volume:86 Issue:06

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