EFFECT OF PROTEIN AND FAT-CONTENT IN FEED ON PLASMA ALANINE-AMINOTRANSFERASE AND HEPATIC FATTY INFILTRATION IN MINK

The effect of the content of protein and fat in the feed on the develo pment of fatty infiltration of the liver in the period from weaning un til pelting was measured in two groups of male scanblack mink (Mustela vison) fed 20 % and 45 %, respectively, of metabolizable energy (ME) from protein. Furthermore, plasma activity of alanine-aminotransferase and the content of specifically chosen clinical-chemical variables in the blood were measured. At pelting time in December, the liver weigh ts were absolutely and relatively heavier to body weight and had a con siderably higher fat-content at 20 % of ME from protein than at 45 % o f ME from protein. From August to pelting time, the activity of alanin e-aminotransferase in plasma was higher at a low protein level than at a higher protein level in the feed. It is concluded that the content of protein and fat in the feed affects the incidence of hepatic fatty infiltration in mink. In the growth period, it is possible, based on p lasma activity of alanine-aminotransferase, to select animals with his tological fatty infiltration of the liver.