[The morphology and function of the liver in high performance cows 2 weeks post partum]

Liver biopsies taken 2 weeks post partum from 213 high-yielding cows (6000-8000 kg FCM per 305 days lactation) were investigated biochemically to liver lipid content (GL) and histologically to degree of lipid infiltration (GdL). Additional in 27 cases electron microscopic studies to liver cell morphology and clinico-chemical investigations (beta-OH-butyrate and acetate in blood; quantity of bilirubin, albumin, protein, activity of ASAT and GLDH in blood plasma) were carried out. 22.5% of liver biopsies were histologically free of lipid infiltration (GL: 2.34%; GdL: 0). 77.5% of liver biopsies showed different lipid quantities (GL: 5.1-24%; GdL: 0.3-5.7%). 27 cases additionally investigated electron-microscopically and clinico-chemically can be summarized in 3 groups (with regard to lipid contents): 1. < 5%, n = 7; 2.5-10%, n = 10; 3. 10-24%, n = 10. Electron microscopic changes concerned occasional nucleus alterations, frequent RER dilation, mitochondria condensation or swelling, occurrence of secondary lysosomes and glycogen decrease. RER dilation and mitochondria swelling showed a statistical relation to liver lipid content. Ketone body (beta-OH-butyrate, acetate) and bilirubin concentration climbed with increasing quantity of liver lipid. Activities of GLDH and ASAT failed any dependence to lipid quantity. The results are discussed under the aspect of pathogenesis and dignity of fatty degeneration of the liver post partum.