Concentration of soybean lecithin affects short-term storage success of goat semen related with seminal plasma removal

Abstract

The objective of this study was to investigate the need of seminal plasma removal for short-term cooling of buck semen in soybean lecithin (SL) based extender. Each pool was divided equally, and one half was subjected to centrifugation to remove seminal plasma (SP-), while the other half remained with seminal plasma (SP+). Then, both SP+ and SP-samples were diluted in two SL extenders (extender A = 1% SL; extender B = 2% SL), cooled to 5ºC and stored for 48 hours. The sperm kinetics, evaluated by CASA, and plasma membrane integrity (PMI), acrosomal integrity (ACI) and high mitochondrial membrane potential (HMMP), evaluated by epifluorescence microscopy, were determined within five minutes after reaching 5°C (T0), as well as after 24 (T24) and 48 (T48) hours of storage. Interactions (seminal plasma vs. extender vs. time;) were observed for all variables assessed. Total and progressive motility and other variables of sperm kinetics decreased after 24 hours of cooling in the SP+ group, and after 48 hours of storage, these same variables were lower in SP+/B compared to SP-/B groups. Furthermore, SP+ reduced PMI (extender B, T48), HMMP (A and B extenders, T48) and ACI (extender A, T0) compared to SP-samples. The interactions between seminal plasma and soybean lecithin phospholipids seemed to occur in a time-dependent manner. It was concluded that the removal of seminal plasma improves the quality of goat semen that was cooled in a soybean lecithin-based extender, especially when using 2% soybean lecithin.

Chemically defined diluent based on Tris-casein in freezing goat semen

“…The evaluation of plasma membrane integrity (iPM) was determined by the double staining method, using the combination of carboxyfluorescein diacetate (CFDA; 0.46 mg/ml in DMSO) and propidium iodide (PI; 0.5 mg/ml in PBS), as described by Araújo Silva et al (2019). For each group, an aliquot of the sample (30 μl) was stained with 5.0 μl of CFDA and 5.0 μl of PI and incubated for 10 min (25 °C).…”

“…Acrosome integrity (iAC) was assessed using Peanut Agglutinin-conjugated fluorescein isothiocyanate dye (FITC-PNA; 100 μg/ml in PBS) (Araújo Silva et al, 2019). Aliquots (10 μl) of the sample were used to make a smear, which was airdried, stained with 30 μl of FITC-PNA and incubated in a humid chamber (4 °C for 15 minutes) in the dark.…”

“…Mitochondrial membrane potential (MMP) was evaluated using lipophilic cationic fluorochrome (JC-1; 0.15 mM in DMSO) (Araújo Silva et al, 2019). To this end, 30 μl aliquots of the sample were stained with 5.0 μl of JC-1 and incubated for 10 min (25 °C).…”

“…In order to solve the obstacles described above and allow a more adequate and safe processing of semen, some alternatives for the substitution of skimmed milk and egg yolk have been reported, among which soy lecithin can be highlighted (Alcay et al, 2017;Mehdipour et al, 2017;Najafi et al, 2017;Araújo Silva et al, 2019), caseinate (Da silva et al, 2020) and low-density lipoproteins (Luna-Orozco et al, 2019). Diluent based on these components have demonstrated a protective effect on sperm cells, a fact that makes them important alternatives for the formulation of seminal extenders (Alcay et al, 2017;Araújo Silva et al, 2019;Da silva et al, 2020).…”

Effect of insulin-like growth factor-1 complex of Simmental bull seminal plasma on post-thawed Kacang buck semen fertility

“…Available at www.veterinaryworld.org/Vol.14/August-2021/12.pdf Goat sperm is cryosensitive [5] due to the seminal plasma of goat semen itself [11]. In the freezethaw process, the lipase in the seminal plasma of goat semen reacts to phospholipids [12], weakening the interaction between the seminal plasma proteins and the sperm surface, decreasing seminal quality [13]. Meanwhile, bull seminal plasma contains the Insulin-Like Growth Factor-1 (IGF-1) complex.…”