Irradiation of semen doses with LED‐based red light in a photo chamber does not improve in vitro quality of thermically stressed boar spermatozoa

Abstract

Recent reports indicate that stimulation of liquid-stored boar semen with red LED-based light improves sperm quality and reproductive performance in sow herds. So far, in vitro data after LED stimulation of whole semen doses are lacking. In this study, the effect of LED light exposure on the in vitro quality of boar spermatozoa after storage and thermic incubation was examined. Boar semen doses were stored at 17°C (n = 10) or 5°C (n = 6) in Beltsville Thawing Solution extender and then exposed to red LED light using a commercial photo chamber. During a subsequent long-term incubation at 38°C, neither sperm kinematic parameters nor mitochondria function or membrane integrity differed between control and treated samples (p > .05). It is concluded that stimulation of semen doses in the LED-photo chamber does not improve quality of thermically stressed boar sperm in vitro. Other than the sperm traits tested here might be involved in the previously reported improvement of in vivo fertility.

LED‐based red light photostimulation improves short‐term response of cooled boar semen exposed to thermal stress at 37°C

“…In dog spermatozoa irradiated with laser light (655 nm), total motility is maintained up to 45 min after exposure (Corral‐Baqués et al, ). On the other hand, using the same photostimulation system as in our study, a gradual decrease in the time for total motility was reported, which was significant after 90 min of incubation at 38°C, using semen doses of 95 ml stored in transparent plastic tubes, concluding that the photostimulation does not improve the in vitro quality of diluted boar semen (Luther et al, ). These differences can be explained by the sample volumes used during the procedure and also by the handle of the doses that were submitted to a stressed by hypothermic storage and/or thermic stress.…”

“…Regarding spermatozoa, Light irradiation it has been reported to have beneficial effects on motility and kinetic parameters in tilapia fish, ram, dog and buffalo spermatozoa (Abdel‐Salam et al, ; Corral‐Baqués, Rigau, et al, ; Zan‐Bar et al, ), and also, an increase in the long‐term storage longevity o turkey spermatozoa was reported (Iaffaldano, Meluzzi, Manchisi, & Passarella, ). With respect to boar spermatozoa, a study reported no differences in the photostimulation of 90 ml seminal doses (Luther, Thi, Schäfer, Schulze, & Waberski, ). However, another report indicated that the photostimulation of boar semen stored in commercial extender in refrigeration conditions increased the main “in vivo” fertility parameters when this semen was utilised for an “in‐farming” standard AI procedure (Yeste et al, ).…”

Photo Stimulation of Seminal Doses with Red LED Light from Duroc Boars and Resultant Fertility in Iberian Sows

“…In pigs, a red LED-based photostimulation procedure (10 min illumination, 10 darkness, and 10 illumination) is able to increase the whole boar sperm response to both the heat stress due to incubation at 37 • C for 90 min and the achievement of in vitro capacitation and subsequent progesterone-induced acrosome reaction [4]. However, in later studies, other groups did not find any improvement in motility, mitochondrial activity, nor viability after the same illumination procedure [19]. Finally, an increase in motility parameters after red LED stimulation was detected, but no alteration in viability, ROS production, or intracellular calcium [20].…”

Red‐light stimulation of boar semen prior to artificial insemination improves field fertility in farms: A worldwide survey

“…In the case of boar semen, a previous study found that LED‐based red‐light stimulation increased its in vivo fertilizing ability (Yeste et al, ). While this study was performed in one farm, further reports showed inconsistent effects of red‐light stimulation on sperm quality parameters evaluated in vitro (Luther, Thi, Schäfer, Schulze, & Waberski, ; Pezo et al, ).…”