Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Animal Science


Two feeding trials were conducted to examine the effect of type of dietary fat and protein on cholesterol metabolism of young pigs. Pigs in both trials were fed diets containing either soybean oil or beef tallow and soy protein isolate or ground beef. Type of dietary protein did not have a significant effect on any parameter measured in either trial. Significant effects of type of dietary fat, however, included greater plasma cholesterol and lipoprotein cholesterol concentration in pigs fed tallow compared with pigs fed soybean oil. Tissue cholesterol (heart and skeletal muscle) was greater in pigs fed soybean oil, and total lipids were greater in livers of pigs fed tallow. Fatty acid synthesis was increased in subcutaneous and perirenal adipose tissue of pigs fed tallow. Tallow-fed pigs also had greater number of very small and very large adipocytes than did pigs fed soybean oil;In vivo kinetic parameters of plasma and lipoprotein cholesterol and measurements of dietary cholesterol absorption were examined in the second trial. As in the first trial, pigs fed diets containing tallow had greater plasma and lipoprotein cholesterol concentration than did pigs fed soy diets. Tissue cholesterol concentrations (liver, skeletal muscle, aorta, and viscera) were greater in pigs fed soy diets than in beef-fed pigs. Kinetic analyses indicated greater turnover of lipoprotein cholesterol in VLDL and HDL fractions of soy-fed pigs. Diet did not affect percent of dietary cholesterol absorbed as measured by two methods. Turnover of plasma cholesterol was unchanged by dietary treatment;Results from the two trials suggest that dietary fats and not dietary protein have significant effects on cholesterol metabolism in pigs; that is, unsaturated fats cause a redistribution of cholesterol within body pools such that changes in concentrations occur in metabolic subcompartments, but not in overall kinetics of metabolism of cholesterol.



Digital Repository @ Iowa State University,

Copyright Owner

Glenace Baldner Shank



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229 pages