Effect of storage temperature, nitrogen gassing and sperm concentration on the in vitro semen quality and in vivo fertility of liquid bull semen stored in INRA96

Abstract

The aim of this study was to assess the effect of storage temperature, nitrogen (N) gassing and sperm concentration on in vitro characteristics and calving rate (CR) following artificial insemination (AI) of liquid bull semen stored in INRA96. In Experiment 1 the effect of liquid bull semen diluted in either N bubbled or non-bubbled INRA96 at a concentration of 5 × 10 sperm per 0.25 mL insemination dose and stored at 5 or 15 °C was assessed subjectively for total and progressive motility on Days 0, 1, 2, 3 and 4 post collection. In Experiment 2a, the effect of stored liquid semen at three sperm concentrations (3, 4 or 5 × 10 sperm per 0.25 mL insemination dose) on total and progressive motility was assessed subjectively on Days 0, 1 and 2 post collection. In Experiment 2b, the field fertility of liquid semen stored at ambient temperature at a concentration of 3, 4 or 5 × 10 sperm per 0.25 mL dose and inseminated on Days 1 or 2 post collection was assessed in comparison to frozen-thawed semen (total of n = 5742). In Experiment 1, total and progressive motility decreased with increased duration of storage (P < 0.01); however, there was no effect of N bubbling on motility on Days 0, 1, 2, 3 and 4 of storage. There was an effect of temperature on total and progressive motility, regardless of treatment, as semen stored at 15°C recorded higher motility values than semen stored at 5°C (P < 0.01). In Experiment 2a, there was no effect of sperm concentration on total or progressive motility on Days 0, 1 or 2 of storage. There was a linear decrease in motility with increased duration of storage (P < 0.01); however, there was no sperm concentration by day interaction. In Experiment 2b, there was an effect of sperm concentration on CR (P < 0.01); semen diluted to 3 and 4 × 10 sperm per dose resulted in a lower CR after 2 days of storage (41.1 and 44.7%, respectively) in comparison to frozen-thawed semen (55.2%) but did not differ to CR of semen diluted to 5 × 10 sperm per dose on Day 2 of storage. There was an effect of parity, fertility sub-index and days in milk (DIM) at AI on CR (P < 0.01). In conclusion, N bubbling and sperm concentration had no effect on in vitro sperm motility of liquid semen, but this study demonstrated a reduction in CR on Day 2 of storage at lower sperm concentrations in comparison to frozen-thawed semen.

Effect of Sperm Concentration and Storage Temperature on Goat Spermatozoa during Liquid Storage

“…With regard to sperm concentration, the beneficial effect of storing goat sperm doses at low sperm concentration on sperm motility and kinetics was not evident, as observed by other research groups [ 4 , 9 , 11 ]. Different results of sperm motility were obtained in the different experiments of the present study.…”

“…In contrast, Murphy et al [ 4 ] found that bovine spermatozoa stored at lower concentrations showed greater viability and reduced glucose consumption. However, no effect of sperm concentration on sperm PM and hMMP was found [ 4 , 11 ]. This disagreement could be attributed to the use of different species and methodology, and that the fact that they did not use any CASA system for sperm motility assessment.…”

“…Conversely, the reduction of sperm concentration in chilled insemination doses, as well as its combination with different storage temperatures, has recently been studied in cattle [ 4 , 9 , 11 ]. The reduction of bull sperm concentration seems to be beneficial for the fertilisation potential of sperm in vitro, reducing its oxidative stress [ 4 ].…”

Effects of Extender Type, Storage Time, and Temperature on Bull Semen Parameters

“…Although extenders preserve sperm motility even up to three days after collection [23,43], insemination with fresh semen kept longer than 48 h is associated with lower conception rates than insemination with previously frozen semen [44]. The ability of sperm to migrate through artificial mucus in vitro is weakened after 48 h [45], and the causes may relate to motility, time window, extender, viability, the individual bull, and other factors.…”

Review: Understanding the causes of variation in reproductive wastage among bulls

“…Optimum fertility can be achieved with a much lower sperm number when fresh (liquid) rather than frozen-thawed semen is used (2 to 5 million v. 15 to 20 million sperm, respectively; Murphy et al, 2017), maximising the utilisation of genetically superior sires. The higher sperm numbers in cryopreserved semen compensate for the damage during the freeze-thaw process compared with fresh semen and, on average, the same level of fertility is achieved with both types of semen (Murphy et al, 2015).…”