Blood Studies of Breeding Dairy Bulls. I. Hematocrit, Hemoglobin, Plasma Calcium, Plasma Inorganic Phosphorus, Alkaline Phosphatase Values, Erythrocyte Count, and Leucocyte Count

Abstract

Blood analyses of 15 mature dairy bulls (Jersey, Guernsey and Holstein breeds) being used in a bull stud were detd. monthly over a period of 1 yr. Mean values and their standard errors for the Jerseys, Guernseys, and Holsteins, respectively, were: hematocrit value (%) 42.3 + 0.9, 46.3 [plus or minus] 1.2, and 39.5 [plus or minus] 1.8; hemoglobin (Hb) 11.6 [plus or minus] 0.2, 12.2 [plus or minus] 0.2, and 11.6 [plus or minus] 0.15; Ca (mg. % plasma) 10.47 [plus or minus] 0.24, 10.21 [plus or minus] 0.20, and 10.26 + 0.22; inorganic P (mg. % plasma) 4.55 [plus or minus] 0.11, 4.86 [plus or minus] 0.14, and 4.51 [plus or minus] 0.09; alkaline phosphatase (units/100 ml.) 2.1.1 [plus or minus] 0.18, 2.95 [plus or minus] 0.21, and 1.49 [plus or minus] 0.10; erythrocytes (million/ cu. mm.) 6.55 [plus or minus] 0.35, 7.49 [plus or minus] 0.39, and 7.84 [plus or minus] 0.25; leukocytes (per cu. mm.) 8580 [plus or minus] 398, 6444 [plus or minus] 139, and 7416 [plus or minus] 184. Significant breed differences were found for packed red cell vol., alkaline phosphatase values, and leukocyte counts. Packed red cell vol., Hb values, and leukocyte counts increased during the summer mos. when environmental temps. increased over 80[degree]F, while plasma alkaline phosphatase values decreased. Plasma Ca and inorganic P values and erythrocyte counts were not affected by environmental conditions.