Dairy Farmers

George Simms Hammond (1921-2005) was bom on Hardscrabble Road m Auburn, Maine, the son of a dairy farmer. He received his Ph.D. at Harvard Universitv in 1947 and served as professor of chemistry at Iowa State University, California Institute of Technology (1958-1972), and the University of California at Santa Cruz (1972-1978). He was known for his exploratory work on organic photochemistry—the use of light to bring about organic reactions. 

Similar findings on dairy farms in Canada were reported by Stonehouse, et al. (2001). The superior economic performance on organic dairy farms was attributed to lower costs of production for almost all material inputs, including dairy herd replacements and livestock feeds. The organic dairy farmers used more land for feed crop production for the dairy cows in order to be as self-sufficient as possible. The conventional dairy farmers imported crop seeds, synthetic chemical fertilisers and pesticides, feedstuffs and herd replacements, with more of their land being devoted to cash crops. 

The date for cutting silage, haylage or hay will vary between lowland and upland farms and between years. The dairy farmer is more likely to cut early for higher quality silage than the beef and sheep farmer, who is more likely to want more dry matter with less emphasis on quality. 

Adequate levels of lime, phosphate and potash in the soil are especially important for organic dairy farmers, because these nutrients are essential for healthy white clover. The supply of these nutrients and general manure strategy is covered fully by Newton (1993). 

Autumn calving should occur in the three months of September, October and November, although from survey evidence it is clear that most dairy farmers calve their cows over a longer period, calving occurring from August to May, with only 51% of the herd calving between September and November (Taylor, 1982). 

Poultry manure has frequently been found to increase yields of pastures and crops and is a valued organic fertiliser used by horticulturalists and dairy farmers. However, when this has been applied at high rates (more than about 18t/ha), there are reports of damage to crops and pasture. 

Acknowledgements A Canadian Institutes of Health Research/EpUepsy Canada postdoctoral research fellowship (M.D.T.) provided support for this work. This work was supported in part by grants from the National Science and Engineering Research Council (NSERC) and the Dairy Farmers of Canada (DEC). We thank Dr. Craig Behnke for permission to adapt the image presented in Fig. 6.1. 

Anderson HS, Lilis R, Selikoff IJ, et al Unanticipated prevalence of symptoms among dairy farmers in Michigan and Wisconsin. Environ Health Perspect2ir.2 l-226, 1978... 

Anderson HA, Holstein EC, Daum SM, et al Liver function tests among Michigan and Wisconsin dairy farmers. Environ Health Perspect 23 333-339, 1978... 

Polybrominated Biphenyls. No epidemiological studies were located that provided evidence for an association between exposure to PBBs and the occurrence of cancer in humans, although one case report is available concerning gastrointestinal cancer in a Michigan dairy farmer with known exposure to PBBs and other chemicals. 

Bekesi JG. Anderson HA, Roboz JP, et al. 1979. Immunologic dysfunction among PBB-exposed Michigan dairy farmers. Ann N Y Acad Sci 717-728. 

Bekesi JG, Holland JF, Anderson HA, et al. 1978. Lymphocyte function of Michigan dairy farmers exposed to polybrominated biphenyls. Science 199 1207-1209. 

Wolff MS, Aubrey B. 1978. PBB homologs in sera of Michigan dairy farmers and Michigan chemical workers. Environ Health Perspect 23 211-215. 

Cephapirin, a first-generation cephalosporin, is used in form of benzathine or sodium salts for intramammary treatment of mastitis in dry and lactating cows. In the United States, the benzathine intramammary formulations are sold for use by dairy farmers without a prescription. The benzathine salts are further used for intrauterine treatment of endometritis, whereas the sodium salts for parenteral... 

Sometimes farmers may be victims of sabotage by a disgruntled employee who adds drugs to the milk. In the case of coccidiostats, the relatively short withdrawal periods may tempt the farmer to leave out the required switch to a coccidiostat-free final feed. There have been also cases in which farmers have bought cows that supposedly had not been treated, but were. Dairy farmers should always test milk from newly purchased animals before adding it to the tank. An additional problem is that the withdrawal period will probably never be obeyed in case of emergency-slaughtered animals. 

Vaarst, M., Thamsborg, S.M., Bennedsgaard, T.W., Houe, H., Enevoldsen, C., Aarestrup, F. and De Snoo, A. 2003. Organic dairy farmers decision making in the first two years after conversion in relation to mastitis. Livestock Production Science 80 109-120. 

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