Masters Theses

Date of Award

12-1981

Degree Type

Thesis

Degree Name

Master of Science

Major

Animal Science

Major Professor

Gerald R. Bratton

Committee Members

Michael Sims, Robert Schaub

Abstract

Normal whole blood values of aminolevullnic acid dehydratase (ALAD) activity and zinc protoporphyrin (ZPP) concentrations were described in four groups of cattle according to age; C-I) 1 to 16 weeks of age (n=69); C-II) 9 months of age (n=10); C-III) 2 years of age (n=30); C-IV) 10 years of age (n=12). Group C-I was further subdivided by weekly age. All 121 animals had whole blood lead con-centrations less than 10 μg Pb/dl. Hemoglobin, total erythrocytes and leukocytes, MCH, MCHC, MCV, and PCV were measured to assess any possible influence on ALAD activity and ZPP concentrations. Twenty-nine calves from Group C-I were selected to measure the effect of lead on ALAD activity, and 12 animals to measure the effect of lead on ZPP concentration. Four treatment groups were established: L-I) control calves receiving no lead (n=8); L-II) calves receiving 2.7 mg Pb/Kg body wt. for 20 days (n=5); L-III) calves receiving 5.0 mg Pb/Kg body wt. for 4 days and followed for additional 10 days. Treatment Group L-II was not included in the measurement of ZPP concentrations. The lead was given per os in the acetate form dissolved in water daily as a single bolus, with lead dose calculated only as the lead portion. In Group C-I ALAD activity was shown to increase with age through nine weeks (851 nM PBG/ml RBC/hr) at which time the level of activity began to decrease through 16 weeks of age. Calves in C-I (548 nM PBG/ml RBC/hr) had a significantly higher (P < .05) activity than the calves 3 weeks of age or less. The range within Group C-I was 113-1873 nM PBG/ml RBC/hr. Mean ZPP concentrations measured by the hematofluorometer were significantly greater (p < .05) in Group C-IV (3.2 μg ZPP/g Hb) than Groups C-I, C-II, or C-III. The mean ZPP concentration of the com-bined Groups C-I, C-II, and C-III was 2.2 μg ZPP/g Hb. No signifi cant difference was observed between Groups C-I, C-II, or C-III. The effects of lead on ALAD activity and ZPP concentrations were quite evident in all groups. The ALAD activity of Treatment Group L-2 was significantly higher (p < .05) than Treatment Groups L-3 or L-4 but significantly less (p < .05) than the initial measurement of ALAD activity in Group L-2. A negative correlation coefficient of -0.80 was observed between the log ALAD and log blood lead in Treatment Groups L-3 and L-4. In these two treatment groups ALAD activity had dropped from a mean of 548 to 110 nM PBC/ml RBC/hr within 6 hours after the initial dose. By 24 hours, ALAD activity had dropped below 60 nM PBC/ml RBC/hr. During the same time interval, whole blood lead con-centration had increased to a mean of 80 μg Pb/dl. ALAD activity continued to drop after daily doses of lead; however, the blood lead concentrations stayed relatively the same. No significant dif-ference in blood lead concentration or ALAD activity was observed between Treatment Groups L-3 and L-4. Mean ZPP concentration increased from 2.2 μg/g Hb to 7.3 μg/g Hb in Treatment Groups L-3 and L-4. No differences were observed between Treatment Groups L-3 and L-4. No significant correlation between ZPP and blood lead concentrations or between ZPP concentrations and ALAD activity was observed in Treatment Groups L-3 and L-4. Normal hematological parameters were noted during the measure-ment of ALAD activity and ZPP concentrations. Lead did not effect total erythrocyte and leukoctye counts, hemoglobin, MCH, MCHC, MCV, and PCV.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS