Dry cow diet, management, and energy balance as risk factors for displaced abomasum in high producing dairy herds.

The objective of this study was to determine prepartum risk factors for displaced abomasum. The design was a prospective study of 1170 multiparous Holstein cows from 67 high producing dairy herds in Michigan. Each farm was visited four times within a 6-wk period. At each visit, data on nutrition and management were collected. All multiparous cows within 35 d of projected calving were assigned a body condition score, and blood was sampled to determine the concentration of nonesterified fatty acids in plasma. A multivariable linear regression model was used to determine risk factors associated with the incidence of displaced abomasum during lactation on a herd basis. A multivariable logistic regression model with random effect was used to determine risk factors for displaced abomasum on an individual cow basis. Significant risk factors for displaced abomasum included a negative energy balance prepartum (as estimated from plasma nonesterified fatty acids), a high body condition score, suboptimal feed bunk management prepartum, prepartum diets containing > 1.65 Mcal of net energy for lactation/kg of dry matter, winter and summer seasons, high genetic merit, and low parity.