Skip to main content
ARS Home » Research » Publications at this Location » Publication #65735
Title: NEGATIVE RELATIONSHIP BETWEEN BLOOD CONCENTRATIONS OF FOLLICLE-STIMULATING HORMONE (FSH) AND TESTICULAR SIZE IN MATURE BOARS

Author
item Ford, Johny
item Wise, Thomas
item Lunstra, Donald

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Relationships between blood FSH and testicular size along with daily sperm production were evaluated retrospectively with data from 5 previous studies of pituitary-testicular endocrinology in Meishan (MS), White composite (WC) and crossbreds of these. In a random sample of boars, FSH was sixfold greater (P<.01) in MS than in WC boars (N=22/group). Daily sperm production/g of testis (estimated by counting elongated spermatid nuclei i testicular homogenates) was similar in these 2 groups, but testicular weight (TWT), adjusted for body weight, was less (P<.01) in MS than in WC yielding lower total daily sperm production (TDSP; P<.05) in MS boars. In 4 other studies (1 with MS, 1 with WC and 2 with crossbreds; N=51 males) boars were selected for extremes in FSH concentrations from a larger population. Differences in FSH of 2.6-, 3.0-, 2.8-, and 3.8-fold were associated with differences (P<.05) in TWT of 1.5-, 1.8-, 1.8-, and 1.5-fold, respectively. Coincident with FSH differences, TDSP differed by 1.4-, 2.2-, 2.8-, and 1.5-fold, respectively and attained significance (P<.05) in 2 of these 4 groups. In the last group described above, fertility was estimated by mating a minimum of 13 estrous females/boar and calculating conception rate on basis of females that farrowed. Conception rate ranged from 28-93% and was greater (P<.05) in the 6 boars with low FSH than in the 7 with high FSH. These studies document a negative relationship in mature boars between FSH secretion and testicular size accompanied with decreased TDSP; basis for this relationship remains unknown. If the positive correlation (r=.7; P<.01) between testicular size and conception rate is substantiated in larger studies, this would provide a convenient method to enhance fertility by culling mature boars with small testicles.