Serum Alkaline Phosphatase Activity in European and Brahman Breeds of Cattle and their Crossbred Types

Abstract

The alkaline phosphatase was determined in a total of 299 cattle using para-nitrophenyl phosphate as the substrate. The animals in this study included animals of the Bos taurus or European breeds, of the Bos indicus or Brahman breeds, and of some of their crosses. The following conclusions may be drawn: The average of serum alkaline phosphatase activities of immature Brahman cattle is approximately twice that of the European breeds of the same age. Crossbreds such as the offspring of crosses between the Brahman and the Hereford or Jersey, and the Santa Gertrudis breed have phosphatase levels which fall between the European and Brahman breeds. Although the alkaline phosphatase activity of bovine serum decreases with age, Brahman cattle continue to have the higher phosphatase levels. Selection for dairy type as opposed to selection for beef type has little or no significant effect on the serum alkaline phosphatase. Sex has no marked effect. Repeatability of the serum alkaline phosphatase within groups of Angus or Hereford bulls or Hereford steers is low, suggesting a considerable effect of environmental factors. In Hereford and Angus bulls, the phosphatase level appears to be negatively correlated with factors affecting rate of gain, efficiency of feed utilization and feed intake.