Interrelations of Number, Average Weight and Progesterone Content of Corpora Lutea in Swine

Abstract

Gilts were slaughtered at 25, 70 and 105 days of gestation and numbers and weights of corpora lutea determined. Chemical analyses of progesterone were made on the corpora lutea from the 70-day stage. The correlation of number and average weight of corpora lutea was −0.34, P<0.01, as calculated between gilts, and −0.04 between ovaries within gilts. The correlation of average weight in the right ovary and in the left ovary was 0.79, P<0.01, and of number of corpora lutea in the right ovary and in the left ovary was −0.44, P<0.01. The standard partial regression of total luteal tissue on average weight of corpora lutea on the linear scale was 0.78, and on number was 0.93. Correlations of 0.44, P = 0.09, were calculated between gilts for average weight of corpora lutea and progesterone concentration, and of −0.41, P = 0.09, between number and concentration. Between ovaries within gilts these correlations were 0.01 and −0.03, respectively. The correlation of progesterone concentration in the right ovary and in the left ovary was 0.78, P<0.01. Standard partial regressions of total amount of progesterone on total luteal tissue on the linear scale was 0.41 and on progesterone concentration 0.90. A correlation of 0.00 was found between amount of luteal tissue and progesterone concentration. Copyright © . .