Comparison of circulating concentrations of reproductive hormones in boars of lines selected for size of testes or number of ovulations and embryonal survival to concentrations in respective control lines.

Abstract

The objectives of this study were to determine whether circulating concentrations of genadotropins and gonadal hormones of boars were altered as a result of selection of pigs for size of testes or for embryonal survival and(or) number of ovulations. Included in Exp. 1 and 2 were boars with the greatest estimated paired weight of testes (TS) and boars from a control (C) line. Concentrations of FSH were similar (P > .10) in boars from the TS and C lines. In Exp. 3, 4, and 5, circulating concentrations of FSH and 17 beta-estradiol (E2) were evaluated in neonates, during pubertal development, and in mature boars of lines selected for an index of number of ovulations and embryonal survival (I), and data were compared to those for boars from a respective C line. Concentrations of E2 were not different in boars from the I line and those from the C line during the early neonatal period but were greater (P < .05) in boars of the C line than in those from the I line during pubertal development. Concentrations of FSH were greater (P < .05) in mature boars from the I line than in those from the C line. In summary, selection for size of testes did not influence circulating concentrations of FSH in mature boars. The secretory pattern of E2 in boars before puberty changed as a result of selection for embryonal survival and number of ovulations in females of the I line, and the different patterns of circulating E2 early in life may result in enhanced circulating concentrations of FSH in adult boars of the I line compared with boars of the C line.

Comparison of plasma FSH concentration in boars and gilts from lines selected for ovulation rate and embryonal survival, and litter size and estimation of (co)variance components for FSH and ovulation rate.

“…Results of the present study differ from those of a previous comparison of pigs of lines I and C. Mariscal et al (1996) sampled pigs from these lines at between 1 wk and 6 mo of age. No significant differences between lines in plasma concentration of FSH were found.…”

“…No significant differences between lines in plasma concentration of FSH were found. Mariscal et al (1996) used the index of ovulation rate and embryonal survival to select six sons of the five highest-indexing and six sons of the five lowest-indexing females in both Lines I and C. In the present study, 60 boars were randomly selected from both Lines I and C. Thus, differences in sampling criteria and(or) sample size may explain the fact that differences between lines for concentration of FSH at 90 d were found in the present study but not in the previous study.…”

Haplotype analysis of β‐actin gene for its association with sperm quality and boar fertility

“…A significant association of the plasma FSH concentration was found with testis weight as well as its closely related traits, testis size and volume (Borg et al 1993;Zanella et al 1999). In addition, a positive correlation was found between ovulation rate and FSH concentration in boars (Mariscal et al 1996;Cassady et al 2000). These studies indicated that plasma FSH, testis characteristics and ovulation rate can be controlled by a similar set of genes.…”

“…1999). In addition, a positive correlation was found between ovulation rate and FSH concentration in boars (Mariscal et al. 1996; Cassady et al.…”

An Approach for Investigating Sexual Maturity in Wild Boar Males: Testosterone and 17β-Estradiol Analysis

“…In addition to seasonal fluctuations, daily fluctuations in testosterone secretion are also mentioned in the literature, although these are more pronounced in animals before puberty or are individual-related [ 29 , 30 , 31 ]. A peak in hormone concentrations is also reported during puberty [ 18 , 32 , 33 ], being the stimulus for Sertoli cells to complete spermatogenesis.…”