Considerations for out-wintering the dairy herd
Quests for profitability and increased public interest in farm animal welfare have fostered a need to investigate winter housing options for low-input and organic dairy herds. Dairy cattle are commonly housed outdoors during the winter months in New Zealand and Ireland. Housing options in Minnesota, which has much colder winters, include tie-stall barns, free-stall barns, compost barns, and “out-wintering” on bedded packs with wind shelters.
We have long known that beef cows and older dairy heifers can thrive with minimal shelter during Minnesota winters. In contrast, milk cows have generally been kept indoors, in part because they were milked in tie-stall barns. More recently, curtain-sided free stall barns have become the standard housing of new construction for larger herds.
Out-wintering continues to increase in popularity, and our stakeholders identified the economics of housing systems as an important research topic. In particular, they asked if out-wintered dairy cattle could stay healthy and comfortable. If so, out-wintering could reduce winter housing costs.
We recently completed the first-two years of a three-year study to develop practical strategies for organic dairy producers to enhance the profitability of their farm by evaluating two winter housing systems and their effects on economics of organic dairy cows. The results presented are from the winter of 2013 and 2014.
Organic dairy cows at the University of Minnesota’s West Central Research and Outreach Center (WCROC), Morris, MN, that calved during fall and spring calving seasons were used to evaluate production, somatic cell score, dry matter intake, animal hygiene, and behavior of organic dairy cattle housed outdoors on a straw pack or indoors in a compost bedded pack barn.
During the two years, 165 lactating Holstein and crossbred organic dairy cattle were assigned to a winter housing system (straw pack or compost-bedded pack barn). Organic wheat straw was used as bedding for the outdoor straw packs, which were 40 feet wide by 80 feet long, and maintained to keep cows dry and absorb manure throughout the winter. The open-front compost-bedded pack barn (2 pens in the barn) was bedded with sawdust, and the bedding material was stirred twice per day with a small chisel plow. Cows were fed a TMR that included organic corn silage, alfalfa silage, corn, expelled soybean meal, vitamins and minerals.
The straw pack cows had similar milk, fat, and protein production than the compost bedded pack cows (see Table 1). Surprisingly, there were no differences in production between the two winter housing groups of organic cows for milk production or somatic cell score. The groups of cows also had similar dry matter intake, indicating that the cows that were housed on straw packs did not require more feed than cows housed in the compost bedded pack barn. However, cows consumed about 25% more dry matter intake during the winter of 2014 compared to the winter of 2013. The average temperature during the winter months was about 7 degrees colder during 2014 than 2013.
Across the two winter seasons, there were no differences for body weight or body condition score for organic cows. For animal cleanliness, the cows housed on straw packs had udders that were cleaner than cows housed in compost bedded packs (udder hygiene score of 1.45 versus 1.73). We saw no difference in rumination time for cows housed outdoors or indoors.
In future years, we will focus on the profitability of the two winter housing systems for organic dairy cattle. Economically, animals outdoors may require about 15 to 20% more feed for the season than animals kept in confinement housing, so improvements in animal health and welfare from out-wintering will need to exceed increased feed costs if out-wintering is to be a profitable option.
There are several obvious benefits to out-wintering; building costs are lower, diseases associated with close confinement and poor ventilation are avoided, animals are generally cleaner, bedding costs could be reduced, feeding may be simplified, and herd size may be adjusted if weather conditions change quickly. There are five key messages to consider when considering outwintering, 1) provide adequate wind protection, 2) additional feed may be required for cows and heifers, 3) lactating cow teats should be dry before they leave the milking facility during cold weather, 4) health problems tend to be fewer than cows housed indoors or in confinement facilities, and 5) housing under the stars may not be for everyone.
For more information, go to the eOrganic website to view Dr. Heins presentation on out-wintering cattle.
|Table 1: Means for cows housed in a compost bedded pack barn versus an outdoor straw pack|
|Measurment||Compost Bedded Pack||Outdoor Straw Pack|
|Energy-corrected milk (lb)||34.2||33.7|
|Somatic cell score||2.75||2.88|
|Dry matter intake (lb)||42.1||41.4|
|Body weight (lb)||1,157||1,232|
|Body condition score||3.28||3.28|
|*P<0.05 for contrast of difference from compost bedded pack cows|