Dale A. Wade

Document Type

Dissertation - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)


Animal Science

First Advisor

Robert N. Swanson


Excessive dietary manganese in young mammals has depressed hemoglobin levels, red blood cell synthesis and growth in some investigations, while in other research these were increased. Toxic levels, mode of action and specific physiological effects are unknown although manganese, cobalt and iron appear to compete for absorption mechanisms. Manganese functions in enzyme systems and in carbohydrate and lipid metabolism, is present in red cells and plasma and may be incorporated into the hemoglobin molecule. Gravid gilts were utilized in these investigations since piglet anemia is an economic problem and manganese effects in swine have not been fully defined. Gilt rations were formulated to meet swine requirements as suggested by the N.R.C. Gestation rations contained 310.9 ± 22.2 ppn iron and 115.3 ± 7.1 ppm manganese. Lactation rations contained 251.2 ± 25.8 ppm iron and 94.3 ± 5.4 ppm manganese. Water contained trace amounts of each element. Two levels of manganese chloride were injected intraperitoneally into purebred Duroc and Hampshire gilts during the last month of gestation to evaluate effects on plasma and red cell iron and manganese levels, hemogram responses and toxicity in gilts and newborn pigs. Treatments were 1, 2 or 3 weekly doses of 1.0 mg Mn+2 /kg or 1 or 2 weekly doses of 0.5 mg Mn+2/kg gilt body weight, respectively. Pre-partum gilt blood samples were drawn prior to treatment and weekly thereafter for a minimum of 5 weeks post-partum. Pig blood samples were drawn on day 1 and weekly to 35 days of age. Red blood cell (RBC), white blood cell (WBC), packed cell volume (PCV), hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) values were determined for each sample. Red cells and plasma were analyzed for iron and manganese concentrations. Statistical analysis of gilt data indicated highly significant (P<.01) differences in treatment RBC, PCV and Hb; breed RBC, MCV and plasma iron; treatment x breed plasma iron; weekly WBC; weekly plasma iron and gilts within treatment x breed RBC iron. Significant (P<.05) differences were present in treatment WBC, MCV, MCHC, RBC iron and RBC manganese; breed Hb; treatment x breed WBC and MCHC; treatment x week Hb; breed x week WBC, PCV and Hb; treatment x breed x week MCHC and plasma iron and in gilts within treatment x breed RBC, WBC, and PCV. Statistical analysis of pig data indicated no significant difference in breed MCV and plasma manganese, treatment x breed MCV and MCH and breed x age MCHC. Breed x age PCV and Hb, treatment x breed x age plasma iron and age x gilts within treatment x breed MCHC were significantly (P<.05) different. All other values due to treatment, breed, age and all interactions were highly significant (P<.01). Critical daily observations of gilts and pigs indicated that real treatment and breed differences were present since Duroc gilts exhibited much greater toxic responses than Hampshire gilts. Crossbreed (Spotted x Duroc) pigs differed from Hampshire pigs in all parameters measured when composite treatment and breed treatment data were compared to composite controls and breed controls. Hampshire pigs from treated gilts, as compared to crossbreed pigs, demonstrated depressed activity and appeared less alert throughout the experimental period and rough hair coats appeared during week 2. Percent live births, 35-day survival and 35-day pig weights were lower in pigs from treated gilts than control gilts.

Library of Congress Subject Headings

Manganese -- Physiological effect
Swine -- Feeding and feeds



Number of Pages



South Dakota State University