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ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Livestock Bio-Systems » Research » Publications at this Location » Publication #135723
Title: EFFECT OF PHOTOPERIOD ON PLATELET-ACTIVATING FACTOR CONCENTRATION IN BOAR SPERMATOZOA

Author
item GADDAM, D - CLEMSON UNIVERSITY, SC
item DIEHL, JOHN - CLEMSON UNIVERSITY, SC
item Ford, Johny
item RATHJE, T - DANBRED USA, LLC, NE

Submitted to: Biology of Reproduction Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2002
Publication Date: 7/1/2002
Citation: Gaddam, D.R., Diehl, J.R., Ford, J.J., Rathje, T.A. 2002. Effect of photoperiod on platelet-activating factor concentration in boar spermatozoa [abstract]. Biology of Reproduction Abstracts. 66 (Supplement 1):312-313.

Interpretive Summary:

Technical Abstract: Platelet-activating factor (PAF, 1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is an important phospholipid mediator shown to be involved in fertilization. We recently reported that boars with a 70% or higher fertility history have a higher concentration of PAF in their spermatozoa. In addition, we reported that PAF content of bull sperm was correlated with motility parameters. It is well established that photoperiod and fertility are positively correlated. The objective of this study was to investigate the effect of photoperiod on PAF levels in boar spermatozoa. Sperm samples were collected from each of 14 boars (Large White x Yorkshire) of similar age and experience in May, June and July from a commercial boar stud. Boar semen was collected by the gloved hand method. Two ml of semen, sperm rich fraction, was centrifuged and reconstituted in 0.5 ml of 20% glacial acetic acid. The PAF was extracted by a modified Bligh and Dyer technique and analyzed by Scintillation Proximity Assay (Amersham Pharmacia Biotech, Inc., Piscataway, NJ). A total of 42 samples were examined. The PAF concentrations (mean ± S.D.) were 10.58 ± 9.47, 5.75 ± 4.73 and 5.19 ± 3.21 in May, June and July, respectively. The average fertility rate (pregnant sows/sows inseminated) of each of 14 boars was obtained. A significant difference was found in PAF content between May and June/July (P<0.05), but not between June and July (P>0.05). There was no significant correlation between the PAF concentrations and the fertility rates (r2=0.14, P>0.05). The lack of significance in PAF levels between the June and July sampling period may be due to individual variation among the boars in their ability to resist the effects of decreasing photoperiod. The fertility rates available to us were calculated on an annual basis, so they did not directly reflect fertility alterations during our study period. Based on these results, it appears that the photoperiod is correlated with PAF concentrations in boar sperm. This means that as photoperiod length decreases, the PAF concentrations also decrease. Further studies are required to establish a true relationship among PAF, photoperiod and fertility.