[Diagnosis of fatty liver in dairy cows]. / Diagnostik der Leberverfettung bei der Milchkuh.

From 27 dairy cows with a mean milk yield of 6900 kg FCM (4% milk fat) per 305 day lactation period liver bioptates 2 weeks post partum (p.p.), milk samples 2, 4 weeks p.p., blood samples 0 (partus), 2, 4 week p.p., measurement of backfat thickness 2 weeks prior to calving, 0, 6, 17 weeks p.p. were taken and body weight and milk yield were determined. Fertility results and disorders appearance were recorded too. Total lipid and triglyceride content were analysed in liver tissue. Acetone concentration was determined in milk and 15 clinical-chemical parameters were elucidated in blood samples. Liver fat concentration shows a great variability from 3.9% to 24%. There is no strong reference value for the distinction between physiological and pathological liver fat concentration. Assessment as to whether increased liver fat levels in dairy cow are indicative of liver damage due to a pathological process should include detection of liver cell damage on the basis of plasma enzymes with closest possible specificity of liver. Glutamate-dehydrogenase (GLDH) is recommended. Liver fat content clearly could be defined exclusively from investigation of liver tissue rather than from analysis of blood or milk parameters. Measurement of backfat thickness provided useful information on the post partum lipolysis rate with a good correlation to liver fat (r to -0.72).

[Experimental studies of the evaluation of the energy balance of dairy cows. 1. Milk production and milk composition]. / Experimentelle Untersuchungen zur Beurteilung der Energie-bilanz der Milchkuh. 1. Mitteilung: Milchleistung und Milchinhaltsstoffe.

Proper assessment of the risk to animal health in early lactation has proved to depend decisively on knowledge of intensity of mobilisation processes as well as of the onset and general pronunciation of subsequent regeneration of endogenic energy reserves. Mere calculation of the difference between estimated energy uptake via feed ration and energy output to sustain milk production would not provide a realistic picture of energy mobilisation and deposition in the organism of a dairy cow. Milk fat levels and quantities but also high milk protein levels and quantities were the milk substances which more clearly than others indicated mobilisation of endogenic fat and protein reserves during the first three weeks of lactation. No information could be derived from milk yield and milk substances as to the onset or level of positive energy balance, following redepositing of energy.