Management Factors Affecting Fertility in Sheep

Santolaria, P.; Palacín, I.; Yániz, J.L.

doi:10.5772/18013

Cited by 15 publications

(17 citation statements)

References 130 publications

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“…When the levels of ROS within the cell are high, ROS will attack these PUFA, causing a disruption in membrane integrity [ 15 ]. The correlation between sperm quality and reproductive success has been widely discussed [ 25 , 45 ]. However, some studies performed in ram confirmed the hypothesis that spermatozoa of high fertility rams displayed higher viability than low fertility rams [ 45 , 46 ].…”

Section: Discussionmentioning

confidence: 99%

“…The correlation between sperm quality and reproductive success has been widely discussed [ 25 , 45 ]. However, some studies performed in ram confirmed the hypothesis that spermatozoa of high fertility rams displayed higher viability than low fertility rams [ 45 , 46 ]. This fact could be explained attending to the plasma membrane of sperm is essential for metabolic functions, capacitation, zona pellucida binding, acrosome reaction and membranes fusing.…”

Section: Discussionmentioning

confidence: 99%

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Multiparametric Study of Antioxidant Effect on Ram Sperm Cryopreservation—From Field Trials to Research Bench

Riesco

Álvarez

Anel-López

et al. 2021

Animals

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The optimization of sperm cryopreservation protocols in ram is a feasible tool to reinforce artificial insemination technologies considering the desirable application of sperm by vaginal/cervical or transcervical deposition. Cryopreservation provokes different types of damage on spermatozoa and many of these detrimental effects are triggered by redox deregulation. For this reason, the antioxidant supplementation in sperm cryopreservation protocols to decrease reactive oxygen species (ROS) levels and to equilibrate redox status has been widely employed in different species. Despite this, more fertility trials are necessary to provide the definitive tool to ensure the antioxidant effectiveness on sperm quality. For this reason, in this work, we performed a multiparametric analysis of some previously tested antioxidants (crocin, GSH and Trolox) on ram sperm cryopreservation from field trials to sperm quality analyses focused on new strategies to measure redox balance. Attending to fertility trial, Trolox supplementation registered an improvement concerning to fertility (when we considered high fertility males) and multiple lambing frequency and other complementary and descriptive data related to lambing performance such as prolificacy and fecundity. This positive effect was more evident in multiple lambing frequency when we considered low fertility males than in global male analysis. In vitro analyses of sperm quality confirmed in vivo trials registering a positive effect on sperm viability and redox balance. In this study, we provided the definitive evidence that the role of trolox on redox balance maintenance has a direct effect on fertility parameters, such as prolificacy. The effectiveness of antioxidant treatments was tested, for the first time in ovine species, using an integrative and multiparametric approach combining in vivo and in vitro analyses and novel approaches, such as RedoxSYS. These types of strategies should be applied to improve sperm conservation methods and optimize AI technologies upgrading the correlation between in vitro and in vivo analyses.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Multiparametric Study of Antioxidant Effect on Ram Sperm Cryopreservation—From Field Trials to Research Bench

Riesco

Álvarez

Anel-López

et al. 2021

Animals

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“…This could be attributed to variations on reproductive planning and animal handling between farms [7], human-animal interactions [23], or other stressful management conditions that suppress fertility [50]. According to Santolaria et al [10], fertility rates can be affected positively by the improvement of handling conditions in the farms. Ram affected conception rates significantly, despite the strictly selection of the ejaculates.…”

Section: Discussionmentioning

confidence: 99%

“…Using chilled semen for cervical AI enhances fertility, but increases semen production cost, has time limitations during transportation and often gives irregular results, since the success of the method is affected by many factors. Environmental conditions, management factors, health of males and females and physiological status of ewes are among the factors that need to be controlled before AI implementation [7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Factors Affecting Pregnancy Rate after Cervical Insemination of Dairy Ewes in Greece

2019

J Vet Sci Med

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The objective of this study was to assess the factors affecting success of cervical Artificial Insemination (AI) with chilled semen in intensively reared dairy ewes in Greece. The study involved 1,785 adult ewes from 20 flocks of Lacaune and Chios sheep. A typical estrous synchronization protocol, including intravaginal placement of progestogen sponge for 14 days and injection of equine chorionic gonadotropin at sponge removal, was applied in ewes during mating period. All ewes were cervically inseminated 53-57 hours after sponge removal with chilled semen (15oC) collected from 10 adult purebred Lacaune rams. Pregnancy Diagnosis (PD) was performed by trans-dermal ultrasonography at 35-38 d after AI. The following data were available for each ewe: breed; parity; Body Condition Score (BCS) at sponge placement, at AI and at PD; presence of rams during synchronization and number of previous synchronizations. Recordings during the AI procedure included: onset of synchronization to AI interval; semen collection to AI interval; semen deposition depth; cervical mucus presence; order of ewe; average time required for each animal; ram semen used. The results showed that farm, parity, semen deposition depth, ram, ewe BCS and changes of BCS during the sponge placement-PD period, significantly affected AI success (P<0.05). Overall fertility was 44%. Ewes of 2nd (50.3%) and 3rd lactation (48.1%) had the highest conception rates, that declined as age increased. Ewes in moderate BCS (2.50-3.50) at onset of synchronization (48.4%) and AI (49.4%) had significantly higher fertility than ewes with low (<2.50) or high (>3.50) BCS. Positive energy balance following the onset of synchronization seems to benefit animals with low and moderate BCS, but decrease pregnancy rates of high BCS ewes. In conclusion, selection of appropriate ewes and rams, BCS evaluation prior to synchronization and adjustment of dietary management are key factors dictating pregnancy rates following AI in greek dairy sheep.

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“…So, semen transportation through the cervical canal depends on cervical mucus volume and quality [64]. All Assaf ewes presented a Pink vaginal mucosa and a…”

Section: Color and Lubrication Of Vagina And Cervical Viscositymentioning

confidence: 99%

Estrus Synchronization and Artificial Insemination with Fresh and Chilled Semen in Assaf Ewes

Fornazari¹,

Mateus²,

Correia³

et al. 2018

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This paper aims to study the efficiency of two short-term progestagen (FGA vs. MAP) + eCG treatments in estrus synchronization and artificial insemination (AI) with fresh or chilled semen in Assaf ewes fertility rate. All ewes received a subcutaneous implant of exogenous melatonin 45 days before been treated with short-term progestagens + eCG. By June 1 st , ewes were divided in two groups: half was treated with an intravaginal sponge impregnated with 20 mg of FGA and the other half with an intravaginal sponge impregnated with 60 mg of MAP. Progestagen treatments lasted for 6 days. At sponge withdraw, all ewes were injected with 750 IU of eCG. Ovarian activity was assessed by plasmatic progesterone levels before and after progestagens + eCG treatment. Semen was collected by electro ejaculation and extended with Andromed ® or OviXcell ® . AI was performed 55 hours after eCG administration with fresh or chilled semen. During AI several factors were assessed: vagina mucosa color and lubrication, external cervical Os type, cervical mucous viscosity, semen deposition place and seminal cervix outflow. Semen was deposited as deep as possible without distress or trauma cervix mucosa. All Assaf ewes presented cyclic activity before progestagen + eCG treatments (2 nd fortnight of May).Short-term progestagen + eCG treatments were equally efficient (100.0%). About 76.5% of Assaf ewes were pregnant 41 days after AI. Fertility rate was influenced by external Os type, semen deposition place and seminal cervix outflow. However, this rate was not conditioned by vaginal color or lubrication, cervical mucus viscosity, semen preservation technic and semen extender.

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Management Factors Affecting Fertility in Sheep

Cited by 15 publications

References 130 publications

Multiparametric Study of Antioxidant Effect on Ram Sperm Cryopreservation—From Field Trials to Research Bench

Multiparametric Study of Antioxidant Effect on Ram Sperm Cryopreservation—From Field Trials to Research Bench

Evaluation of Factors Affecting Pregnancy Rate after Cervical Insemination of Dairy Ewes in Greece

Estrus Synchronization and Artificial Insemination with Fresh and Chilled Semen in Assaf Ewes

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