Document Type

Dissertation - Open Access

Award Date


Degree Name

Doctor of Philosophy (PhD)


Animal Science

First Advisor

Richard C. Wahlstrom


Seventy-six primiparous, crossbred gilts averaging approximately 125 to 135 kg were used in a series of two experiments to determine the effects of chlorpropamide upon reproductive and blood criteria. The drug, fed at the rate of 1000 ppm (1816 mg per day) and 3000 ppm (5448 mg per day), was included in a 14% protein basal diet from the day following breeding until gilts were sacrificed after 60 or 95 days of gestation. The 515 fetuses collected from these gilts were used to obtain information about the effects of chlorpropamide on individual weights and blood glucose and fructose levels. Data obtained from both gilts and fetal pigs were subjected to multiple regression to study their effects upon litter size, fetal weight and fetal glucose content. Gestation weight gain of gilts was significantly reduced with the addition of chlorpropamide to the diet. Average litter size and percent embryo survival were not significantly affected, although there was a trend toward better embryo survival with the addition of chlorpropmide, particularly at the higher level. Maternal blood glucose and fructose levelers were not significantly affected by the addition of chlorpropamide to the diet but were significantly reduced by increased gestation length. Applying multiple regression to the gilt variables, blood glucose and fructose levels, did not produce any significant effects upon litter size but blood glucose level did produce a significant negative effect upon average fetal weight. Fetal weights were significantly reduced in those pigs from gilts fed chlorpropamide and this reduction was related to level of the drug fed. Blood glucose levels of fetal pigs from gilts fed chlorpropamide were higher than those in pigs from gilts fed chlorpropamide were higher than those in pigs from gilts fed the basal diet. Feed chlorpropamide to gilts at the 3000 ppm level did not affect blood fructose level of fetal pigs. However, the 1000 ppm level of chlorpropamide in diets of gilts resulted in considerably higher fetal blood fructose than was present in fetuses from gilts fed the basal diet in Experiment 2 but not in Experiment 1. Increased fetal age cause fetal glucose levels to increase and fetal fructose levels to decrease. When the fetal variables, blood glucose and fructose levels, were subjected to multiple regression, significant effects on fetal weight were produced. Fetal glucose level produced a positive effect while fetal fructose level produced a negative effect on fetal weight. Combining fetal and gilt variables and subjecting them to multiple regression with fetal weight being the dependent variable produced significant effects. Fetal blood glucose level and maternal blood fructose level produced positive effects, while fetal blood fructose levels, maternal blood glucose level and litter size produced negative effects on fetal weight.

Library of Congress Subject Headings

Swine -- Breeding
Swine -- Feeding and feeds



Number of Pages



South Dakota State University