The content and composition of lipids in the digital cushion of the bovine claw with respect to age and location--a preliminary report.

The pads of the bovine digital cushion, which serves as a shock absorber, have specific anatomical structures to cope with the substantial forces acting within the claw. To gain more information on the lipid composition and content of the pads, horn shoes from 12 slaughtered heifers and cows were removed and different samples of the pads excised with a scalpel. Pad lipids were extracted and the fatty acid composition determined by gas chromatography. Fat from perirenal and subcutaneous adipose tissues served as a comparison. Overall, this fat contained a higher quantity of extracted lipids than that of the claw pads and did not differ between heifers and cows. In contrast, lipid content in the pads was significantly higher in the cows than in the heifers. In both groups, the lipid content of the middle and abaxial pads, which are situated directly under the distal phalanx, was lower than in the pads of the other locations. The lipids in all pads contained >77% monounsaturated fatty acids (MUFA), differing sharply from the adipose tissue with values <51%. Among the polyunsaturated fatty acids (PUFA) a significantly higher proportion of arachidonic acid (AA) was found in the heifer pads than in those of the cows, whereas the proportion of AA was similar in the adipose tissue of all animals. The proportion of AA in the pad lipids also varied between the defined locations with the highest proportion found in locations that showed the lowest lipid content and was related to the age of the animal.