Studies on Ketosis in Dairy Cattle. XIII. Lipids and Ascorbic Acid in the Liver and Adrenals of Cows with Spontaneous and Fasting Ketosis

The few reports available (1,2,3,6,9) relative to the condition of the liver of cows and ewes with ketosis deal primarily with the pathology of this organ.In these reports a fatty liver always has been observed to be a part of the ketotic syndrome so that it has been assumed rather generally that the livers of ketotic ruminants always are fatty.It also has been shown by Groenewald et al. ,(1) with ewes and by Shaw et al. (8) on cows, that the adrenals tend to be fatty.The adrenal also was implicated when an extract from it was found to promote recovery of cows with ketosis (Shaw, 7).It was deemed advisable to conduct further studies to determine whether these abnormalities are associated with the early development of ketosis or are secondary to the inanition associated with ketosis. EXPERIMENTAL PROCEDUREStudies were conducted on cows exhibiting spontaneous ketosis and on cows which had been fed at either a medium or low plane of nutrition postpartum.The feeding and management of the experimental cows was discussed rather briefly in a previous report (5).The blood glucose and acetone bodies were determined in all cases but will be reported elsewhere in connection with other studies.The methods used were similar to those discussed in a previous communication with the exception that the lipids were extracted from the ground tissue by repeated extraction with a warm alcohol-ether mixture (2: 1) and purified by resolving in petroleum ether.Ascorbic acid was extracted from macerated tissue with 2.5 per cent metaphosphoric acid.Liver samples were obtained by biopsy and also after slaughter. RESULTSLiver lipid and aseorbic acid values of cows with both uncomplicated and complicated ketosis are presented in table 1.When compared with normal cows in mid-lactation, the total liver fat values will be observed to be high in most cases.The total cholesterol of the liver of the ketotic cows was much higher than that of normal cows in mid-lactation, the increase being due mainly to the ester cholesterol fraction.The free cholesterol fraction which represents the main form of cholesterol in the liver of normal cows is proportionally low in cows with ketosis.The ascorbic acid values vary widely, with some of the values being relatively low.