Effect of boar ejaculate fraction, extender type and time of storage on quality of spermatozoa

Abstract

The aim of this study was to investigate the effect the sperm-rich fraction (F1) and the post-F1 fraction (F2) on the quality of boar spermatozoa stored in a liquid state. Ejaculates were collected from three Polish Landrace boars. Each ejaculate fraction was diluted with BTS short-term extender and Safe-Cell Plus (SCP) long-term extender and stored for seven days (D1-D7) at 17 o C. Analyses included sperm motility parameters, normal apical ridge (NAR) acrosomes and plasma membrane integrity (PMI). Prior to the dilution of fractions, marked changes (p<0.05) were noted between F1 and F2 in progressive motility (PMOT), velocity average pathway (VAP) and velocity straight line (VCL). After the ejaculate was diluted, the type of fraction and type of extender significantly affected (p<0.05) PMOT, being markedly higher (p<0.05) for F1 extended in BTS. No marked changes (p<0.05) were observed between F1 and F2 extended in SCP for any of the analyzed sperm quality parameters during seven days of storage. Significantly higher (p<0.05) values of sperm quality parameters were noted in F1 compared with F2 for BTS on D7 of storage. The results of the four-way ANOVA analysis indicate that boar, fraction of ejaculate, extender type and day of storage had significant effects on the quality of boar stored spermatozoa. The F1 was characterised by higher quality of spermatozoa during storage in comparison with F2 in the short-term extender. Using the long-term extender containing the proteins allowed for a better application of F2, which could be important for the pig industry.

Preservation of boar semen: An update

“…There are commercial extenders (Beltsville TS [BTS], Modified Modena [MM] and MR‐A) that are effective for the extension and storage of boar semen, reaching on average 80% in gestation rates and 11 live births if the AI is done on the first day, whereas fertility is preserved if the number of sperm extended in BTS and MR‐A is doubled to 4 days (Johnson, Aalbers, & Grooten, ). The interaction of such factors as the ejaculate fraction, the extender, the boar and storage days significantly influences the quality of liquid‐stored sperm (Dziekońska, Świąder, et al, ), affecting mainly DNA integrity (Bielas, Niżański, Partyka, Rząsa, & Mordak, ); however, the main factors that affect cell functionality are the collection and storage temperature after dilution and the extender used (Johnson et al, ). The lipid composition of the sperm membrane in pigs is associated with cryotolerance (Yeste et al, ), since the cholesterol–phospholipid and protein–phospholipid ratios, 0.26 and 1.26 respectively (Parks & Lynch, ), increase sperm susceptibility to thermal shock, which occurs when the fresh semen cools off quickly from body temperature to 15°C (Johnson et al, ).…”

“…The effect of the sperm‐rich fraction (F1) and post‐F1 fraction (F2) was evaluated on the quality of boar sperm stored in liquid for 7 days at 17°C using a short‐term (BTS) and long‐term extender (Safe Cell‐Plus) for sperm motility, viability and acrosomal integrity, concluding that F1 maintains better sperm quality using BTS. The fraction of the ejaculate, the type of extender and the storage time affect sperm quality (Dziekońska, Świąder, et al, ). In addition, the serum protein effect (Porex) has been evaluated in a long‐term extender (TRIXcell+), determining that it maintains an acceptable sperm motility for 10 days compared to the short‐term extender, BTS, which contains bovine serum albumin (BSA) and maintains motility for 3–5 days; however, the pregnancy rate and the birth of live young is better using semen diluted in TRIXcell+ stored for 3–5 days than semen diluted in BTS stored for 1–2 days (90.4 ± 4.0 and 87.9 ± 3.6; 14.2 ± 0.7 and 13.6 ± 0.6, respectively; van den Berg et al, ).…”

Rest days and storage of boar semen at 17°C: Effect on motility and sperm concentration

“…The total motility diminished significantly over the storage days, while the progressive motility remained constant. The maintenance of progressive motility explains why doses kept for 5 days can still be used for artificial insemination (Dziekońska et al, 2017; Vyt, Maes, Dejonckheere, Castryck, & Soom, 2004). Another investigation describes a diminution in progressive motility over the storage days.…”

Detection and characterization of Lactobacillus spp. in the porcine seminal plasma and their influence on boar semen quality

“…In pig production, artificial insemination is widely carried out and the use of fresh diluted semen is predominant. For this reason, there are increasing interests in developing new extenders and in establishing the optimal storage conditions for diluted spermatozoa [ 46 , 47 ]. For short- and long-term co-cultivation of spermatozoa with LAB, a commercial BTS extender was chosen because it warrants preservation during storage for three days [ 5 ].…”