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Corn Silage Management Practices on California Dairies
The aim of this study was to describe current corn silage management practices on California′s Central Valley dairies. In spring 2013, a forage management survey was mailed to dairy producers in California’s San Joaquin Valley (n= 1,100). Producers received an envelope containing an invitation letter, a double sided two-page survey, and a pre-paid return envelope. Response rate was 14.5%. Median herd size was 1,200 cows. Harvest date was decided solely by the dairy producer (53.3%) or by the producer with the assistance of the forage grower, the chopper and/or the nutritionist (23.4%). When the dairy producer was not involved in setting a harvest date, the chopper (12.0%), the grower (7.3%), the nutritionist (0.7%), or the chopper and the grower (3.3%) were responsible for setting the harvest date. Most dairies (75.0%) estimated crop DM prior to harvest, mostly by visual analysis of the milk line. Only one dairy determined DM by shredding and drying plants prior to harvest. The number of choppers operating simultaneously was either one (35.9%), two (50.3%), three (11.1%) or four to five (2.7%). The most common chopper size was eight-row (67.3%), followed by six-row (17.7%), and ten-row (15.0%). One (68.8%), two (29.7%) or three (1.4%) tractors were used for packing the forage on the silage structure. Dairies (62%) weighed every load of fresh chopped corn delivered at the silage pit with a farm scale (58.9%), the custom harvester’s mobile scale (23.2%), other certified scale (16.6%) or other methods (1.3%). Most dairies completed filling their largest silage structure in less than three days (48.5%) or in four to seven days (30.9%). Thirty-two percent reported filling silage structures with more than five different fields of harvested forage, comprised of one (36.8%) or two (40.6%) varieties. Dairies (68.8%) reported covering silage within 24 hours, with all dairies covering silage structures within 72 hours of completion. Daily covering of silage structures was reported from 19.6% of dairies. Dairies (51.0%) used a temporary cover during filling, with duration of filling ranging from one to 60 days on their largest corn silage structure. Dairies that did not use a temporary cover reported pile completion duration up to 15 days on their largest structure. Results from this survey study help us to identify critical control points for education and outreach activities to improve silage management practices at harvest, packing and covering on California’s Central Valley dairies.
Keywords: Silage management, dairies, survey