The effect of age and weight upon the blood volume of farm animals

The need for a knowledge of the amount of circulating blood in man and animal has stimulated investigators in many fields of research to study and apply various methods and techniques for the quantitative determination of blood volume. This has resulted in the controversies and in conflicting reports in the literature. Through these efforts to perfect methods and establish constant values for the different species much information has been acquired from which our present concepts have been formulated.

The increasing popularity and adaptability of farm animals for nutritional, radiation and therapeutic studies using labeled elements and compounds require that acceptable blood volume figures be established for use in experimental interpretations of these results. Aside from the limited early results summarized by Dukes (1947) these for the growing bovine reported by Missouri workers (1931) and the studies with swine by Hansard et. al.(1951), few values have been reported on blood volume determination with farm animals.

In the view of the limited information in the literature concerning the blood volume of the various species of farm animals, this study was initiated with the following objectives; (1) to determine an adaptable procedure for blood volume for the various species; (3) to establish an acceptable value for the blood volume of the various species at definite ages and weights; (4) to determine the limitations of the accepted procedure as affected by in vitro and in vivo studies that make for variations in values reported; and, (5) to correlate the results of this study with values and methods reported in the literature.