Effect of Gamma-Oryzanol-Enriched Rice Bran Oil on Quality of Cryopreserved Boar Semen

108

ContentsWhile sperm cryopreservation is the best technology to store boar semen for long-term periods, only 1% of all artificial inseminations (AI) conducted worldwide are made using frozen-thawed boar sperm. With the emergence of long-term extenders for liquid storage, the use of cryopreserved sperm in routine AI is less required. However, banks of boar semen contain cryopreserved sperm and planning inseminations in AI centres may benefit from the use of frozen-thawed semen. Therefore, there is an interest in the use of this technology to preserve boar sperm. In this regard, although the first attempts to cryopreserve boar semen date back to the seventies and this technology is still considered as optimal, some relevant improvements have been made in the last decade. After giving a general picture about boar sperm cryodamage, the present review seeks to shed light on these recent cryopreservation advances. These contributions regard to protein markers for predicting ejaculate freezability, sperm selection prior to start cryopreservation procedures, additives to freezing and thawing extenders, relevance of the AI-technique and insemination-toovulation interval. In conclusion, most of these progresses have allowed counteracting better boar sperm cryodamage and are thus considered as forward steps for this storage method. It is also worth noting that, despite being lower than fresh/ extended semen, reproductive performance outcomes following AI with frozen-thawed boar sperm are currently acceptable.

Section: Cryopreservation Extendersmentioning

confidence: 99%

Recent Advances in Boar Sperm Cryopreservation: State of the Art and Current Perspectives

Yeste

2015

108

“…Several studies have shown moderate to quite dramatic effects of a variety of antioxidants on in vitro sperm quality. Antioxidants such as BHT (Roca et al 2004), polysaccharides (Hu et al 2013), rice bran oil (Kaeoket et al 2012), rosemary extract (Malo et al 2010) and fennel extract (Malo et al 2012) were able to improve most measures of post-thaw sperm fertility. Others have added the target molecules of the ROS and certain PUFAs in the freezing extenders to improve post-thaw sperm quality (Kaeoket et al 2010b).…”

Section: Cryopreserved Sperm Additivesmentioning

confidence: 99%

The Fertility of Frozen Boar Sperm When used for Artificial Insemination

Knox

2015

Contents One of the limits to practical use of frozen boar sperm involves the lowered fertility when used for artificial insemination. Years of studies have shown that 5–6 billion sperm (approximately 3 billion viable) used in single or multiple inseminations results in pregnancy rates most often between 60 and 70% and with litter sizes between nine and 10 pigs. Yet today, it is not uncommon for studies to report pregnancy rates from 70 to 85% and litter sizes with 11–12 pigs. While global statements about the incidence and reasons for higher fertility are not conclusive, incremental fertility improvements appear independently associated with use of a minimum number of viable sperm (1–2 billion), insemination timing that increases the probability that sperm will be present close to ovulation for groups of females, selection for boar sperm survival following cryopreservation, and modification of the freeze and thaw conditions using additives to protect sperm from oxidative damage. Studies show that techniques such as intrauterine and deep uterine insemination can provide an opportunity to reduce sperm numbers and that control of time of ovulation in groups of females can reduce the need for multiple inseminations and improve the chance for AI close to ovulation. However, optimal and consistent fertility with cryopreserved boar sperm may require a multifaceted approach that includes boar selection and screening, strategic use of additives during the freezing and thawing process, post‐thaw evaluation of sperm and adjustments in sperm numbers for AI, assessment of female fertility and ovulation induction for single insemination. These sequenced procedures should be developed and incorporated into a quality control system for improved fertility when using minimal numbers of cryopreserved boar sperm.

“…Recently, Kaeoket et al. () showed that supplementation of gamma‐oryzanol‐enriched rice bran oil in lactose–egg yolk (LEY) freezing extender resulted in an improvement of frozen–thawed Duroc boar semen qualities (i.e. progressive motility, viability and acrosome integrity).…”

Section: Introductionmentioning

confidence: 99%

Breed of Boar Influences the Optimal Concentration of Gamma‐oryzanol Needed for Semen Cryopreservation

Chanapiwat

Kaeoket

2015

The aim of this study was to investigate the influence of boar breed on the optimal concentration of gamma-oryzanol on the qualities of cryopreserved boar semen. Semen was collected from 20 boars (10 Duroc, 5 Large white and 5 Landrace boars). The semen sample was divided into five groups (A-E) according to the concentration of gamma-oryzanol in extender II, that is 0, 0.08, 0.16, 0.24 and 0.32 mM, respectively. The semen was cryopreserved by nitrogen vapour and storage in nitrogen tank (-196°C). After storage for a week, samples were thawed at 50°C for 12 s and evaluated for progressive motility, sperm viability and acrosome integrity. The results demonstrated that gamma-oryzanol significantly improved progressive motility, viability and acrosome integrity of frozen-thawed boar semen. Considering the influence of breeds on the optimal concentration of gamma-oryzanol, for Duroc boar, gamma-oryzanol at 0.16 mM (group C) yielded the highest percentage of progressive motility, sperm viability and acrosome integrity. For Large white and Landrace boars, gamma-oryzanol at 0.24 mM (group D) showed a significantly higher percentage of progressive motility, viability (not significant in Landrace) and acrosome integrity than other concentrations. In conclusion, the optimal concentration of gamma-oryzanol needed for boar semen cryopreservation in lactose-egg yolk (LEY) freezing extender is not only depended on individual boar but also breed of boar, that is 0.16 mM for Duroc and 0.24 mM for Large white and Landrace.