Disease, production and culling in Holstein-Friesian ...
|Title||Disease, production and culling in Holstein-Friesian cows. VI. Effects of management on disease rates|
|Author(s)||I. Dohoo, S. Martin, A. Meek|
|Journal||Preventive veterinary medicine|
|Abstract||Thirty-two dairy herds within 50 miles of Guelph participated in the 2.5-year study (1979-81). Most herds were in the range of 30-45 milking cows. Three were in loose housing and 29 in tethered housing. All were turned out in summer, and 21 were let out for exercise in winter. The major roughage fed to milking cows was dry hay in 22 farms, maize silage in 5 and hay crop silage in 5. The dependent and independent variables and their regression coefficients are listed. The findings are discussed briefly and compared to those of other authors. There appeared to be a positive association between the frequency of roughage feeding and reproductive efficiency. Supplemental calcium injection of high risk cows appeared to be beneficial in reducing milk fever rate. Feeding maize silage to dry cows did reduce the milk fever risk. Placental retention rate was 6% in the 2 herds receiving vitamin E and selenium in the prepartum period and 8.7% in the other herds. Heavy grain feeding prior to parturition was associated with increased risk of both placental retention and genital infections. Abomasal displacement was more common in loose housing, and was not associated with any dietary factor. Cows in tethered housing had a greater risk of ketosis, and the only nutritional factor was a positive association with maize silage as the major roughage. The negative association between age and clinical mastitis would be explained by culling, and the regular use of products to control oedema seemed to be beneficial..|
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