Improved disease resistance in dairy cattle: Correlation of health disorders with measures of immune status; and Genetic improvement for disease resistance by identifying sires whose daughters have fewer disease problems

In Iowa, dairy cattle are most commonly raised on land having rolling topography. Because the nitrogen contributions of alfalfa, their typical forage, and manure reduce the need for commercial fertilizer application, dairy cattle make a strong contribution to a more sustainable agricultural system. The high productivity of the dairy cattle, combined with the significant savings in purchased inputs, offers some producers a financially stable, environmentally preferable alternative to more traditional row-cropping approaches