This is a final project report submitted to The Ceres Trust.
Investigator: Lucas S. Sjostrom ·Department of Animal Science 205 Haecker Hall, 1364 Eckles Avenue University of Minnesota St. Paul, MN 55108-6118. Telephone 920 691 2154, FAX 612 625 5789 [email protected]
Collaborators: Bradley Heins, Ph.D., University of Minnesota – WCROC, Morris
Project Period: 2013-2014
Organic dairy cows at the University of Minnesota’s West Central Research and Outreach Center, 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 (2013 and 2014), 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. 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.