The Relationships between Plasma Progesterone and LH and the Numbers of Corpora Lutea and Embryos in Purebred and Crossbred Gilts

Abstract

SummaryRelationships between plasma progesterone and luteinizing hormone (LH) and the numbers of corpora lutea and embryos were determined in 133 8-month-old purebred Duroc, Hampshire and Yorkshire gilts and two-breed crosses among the three breeds. The numbers of corpora lutea and normal embryos were determined at slaughteronday 30.8 +-.2 of pregnancy, and progesterone and LH were quantified in plasma obtained the previous day. Progesterone concentrations in plasma were influenced by sire (P<.10), breed of dam (P<.05) and breed of sire • breed of dam (P<.05). Hampshire gilts had higher concentrations of progesterone in plasma than did Durocs (P<.05) and Yorkshires (P<.01). None of the effects in the model was significant for LH. Plasma progesterone and LH had heritability estimates of .48 + .41 and .29 + .40, respectively.Most genetic and phenotypic correlations of plasma progesterone and LH with other traits were small. These data indicate that progesterone concentrations in plasma at 30 days of pregnancy are not a satisfactory predictor of the numbers of corpora lutea and embryos. The differences in plasma progesterone between breeds illustrate the need to consider the breed of gilts when selecting animals for the I Journal Article 3590 of the Agr. Exp. Sta., Oklahoma State Univ., Stillwater. This research was conducted in cooperation with the USDA, SEA-AR. 2We thank Dr. G. D. Niswender (Colorado State University) for the progesterone-63-BSA and porcine LH antibodies, Dr. L. E. Reichert Jr. (Emory University) for the supply of porcine LH for iodination and the NIAMD for the supply of LH standard (NIH-LH-Sjs).3 Anita. Sci. Dept., Oklahoma State Univ., Stillwater 74078.4Present address: Dept. of Anlrn. Sci., Univ. of Nebraska, Lincoln 68500. study of luteal function or physiological factors that may influence progesterone concentrations in plasma.

Genetic Parameter Estimates for Reproductive Traits of Male and Female Littermate Swine

“…This agrees with the report of .68 for sperm concentration (Masek et al, 1979) and suggests that improvement should occur when selecting for increased testicular sperm concentration; however, ease of measurement of this trait could be a limiting factor. The heritability for LH0 was larger than that reported by Wettemann et al (1980; .61 + .46 vs .29 + .40) for basal levels of plasma luteinizing hormone in gilts. Heritability estimates for LH and TE were greatest at 3 h after GnRH treatment of boars.…”

Endocrine Fertility Parameters—Genomic Background and Their Genetic Relationship to Boar Taint in German Landrace and Large White

“…An explanation for the high number of animals under this threshold could be their age. Because PROG was earlier described as an endocrine indicator for the number of ovulations in prepubertal gilts [33], animals in our study may not have reached this hormonal status of puberty, as they were too young, with an average age of 126 days for females and 164 days for males. Additionally, studies dealing with the physiological background of PROG are often performed as a challenge study, during the estrous cycle or in pregnant or sows or gilts [34][35][36].…”