MORRIS, Minn. - Armed with his trowel in hand, Roger Moon looked forward to digging into some pies - cow pies, that is - at the Morris-based West Central Research and Outreach Center's recent organic dairy day.
The University of Minnesota entomologist was on the lookout for cow dung maggots in the center's pastures. As more than 70 organic dairy farmers, researchers and industry leaders looked on, Moon talked about fly management for organic dairy systems.
Moon was one of several speakers at the center's first day-long organic dairy day. Grazing, nutrition, pasture management and the center's studies on once-a-day group feeding of organic dairy calves and organic dairy steer production were among the topics.
Moon pointed to cows bunching at the end of a paddock in the afternoon heat. The cows had their heads toward the center and swished their tails and stomped their legs to keep flies at bay. It's a scene repeated at many farms and can be costly, he said. Stable flies, for example, can reduce a milk output by 2 percent per fly per day.
Keep feed and feed residues dry, spread out or composted. Use sawdust or sand for bedding, he said, and avoid straw.
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Manure should be spread, composted or immersed in water.
Keep on the lookout for active fly breeding sites, he said.
Sticky traps are a source of control, although they don't catch horn flies that ride on cattle, he said. The Bruce walk-thru trap does. The walk-thru is a box-like structure that cows walk through. Fabric dislodges flies, which are then drawn by light to the sides through baffles and then trapped and die. The Bruce Walk-Thru can be placed near the parlor.
Walk-thru traps can be constructed at home, Moon said. Plan designs are available from the North Dakota State University, University of Missouri and University of Arkansas.
Before putting herds on pasture, producers need to consider if it's the right fit for his farm. U of M dairy scientist Jim Paulson offered a flow chart with numerous options. Questions to consider include the farm's ability to produce pasture, adjusting the dairy ration based on current pasture conditions and pasture availability to cows coming from the parlor.
Producers should also consider water availability within 1,000 feet of the paddocks plus a mud-free lane for cows to move from the parlor to the paddocks.
Stocking density is important. High stock density usually means shorter grazing periods, he said. Shorter grazing periods mean more days the paddocks can rest and allows for management of residual forage heights.
Rotational grazing results in increased pasture yield, persistence and vigor of grass species, better forage quality, uniformity of manure distribution and greater animal output per acre. Weeds, erosion, hay feeding and the cost of production are reduced.
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Perennial cool season grasses to consider are Kentucky bluegrass, smooth bromegrass, quackgrass, reed canarygrass and meadow fescue. Bunch-type grasses include orchard grass, timothy and tall fescue.
Perennial legumes like red clover, white clover, birdsfood trefoil, alfalfa and kura clover are others to consider in the grass mix.
From the pasture, the group learned about two of several research projects focusing on the organic herd. The center's dairy scientist Brad Heins and graduate student Elizabeth Bjorklund are researching group feeding of organic dairy calves.
The milk feeders, a New Zealand-style feeder, look like larger pails with multiple well-spaced nipples. The advantages of group feeding include reduction in labor, calf socialization and group learning. It's also easier to bed and clean super hutches than individual hutches.
They've also found some challenges in the system. Grouped calves must be aggressive drinkers. Weak calves must be separated. The calf attendant must be good observer. If the age spread in the calves is large, the older calves will have delayed weaning or the youngest will be weaned too soon. It is also more difficult to provide individual attention.
The calves are fed milk, at a 90-degree temperature, once a day around 8 a.m. The whole milk isn't pasteurized, said Heins.
Calves in the study were assigned to groups of 10 by their birth order in "super hutches." The calves were moved to the hutches on their fourth day.
Groups were fed 1.5 percent of their weight of 13 percent total solids organic milk.
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Heins offered a few tips for group management systems. He suggests separating newborns from fresh cows as soon as possible and hand feed colostrum. Train the calves to drink from a firm nipple in an individual pen during the colostrum feeding period.
New calves should not be added to a group until the calf is a fast, aggressive sucker. Most are ready by the third day, he said.
