Use of Propylene-Glycol as a Cosolvent for GnRH in Synchronization of Estrus and Ovulation in Sheep

Santos-Jiménez, Zurisaday; Guillen-Gargallo, Sara; Encinas, T.; Berlinguer, Fiammetta; Véliz-Deras, Francisco Gerardo; Martínez-Ros, Paula; González-Bulnes, Antonio

doi:10.3390/ani10050897

Cited by 10 publications

(9 citation statements)

References 31 publications

(35 reference statements)

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“…In consequence, there is intense research for alternative protocols, including hormones other than eCG. The substitutes are focused on other hormones, with the capacity for inducing the secretion of LH, like the gonadotrophin-releasing hormone (GnRH; [ 3 , 4 , 5 ]), or possessing LH activity in a similar way to eCG, like human chorionic gonadotrophin (hCG) or human menopausal gonadotrophin (hMG). The high similarity between the hormones hCG and LH causes their binding to the same LH receptor [ 6 ], and, in addition, the higher availability and lower cost of hCG have favored its use over hMG.…”

Section: Introductionmentioning

confidence: 99%

The Use of hCG for Inducing Ovulation in Sheep Estrus Synchronization Impairs Ovulatory Follicle Growth and Fertility

Cano-Moreno

Lago-Cruz²,

Encinas³

et al. 2021

Animals

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Currently, there is an intense effort to find an alternative hormone to eCG to induce ovulation after estrus synchronization treatments in sheep. One of the proposed alternatives is based on the use of hCG, but the results are controversial since fertility rates are commonly affected. The present study aims to evaluate, therefore, the adequacy of hCG in protocols for the synchronization of estrus and ovulation. Ovarian follicle dynamics, occurrence of estrus behavior and subsequent ovulation, quality of corpora lutea, and pregnancy rate after controlled natural mating were assessed in two consecutive trials. The findings indicate that the low fertility rates reported for the protocols based on the administration of hCG for inducing ovulation during estrus synchronization in sheep may be related to a high occurrence of abnormal follicular growth patterns, disturbances, and retardments of ovulation and concomitant formation of follicular cysts in the treated females. These results preclude their practical application to induce ovulation concomitantly to estrous synchronization treatments.

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Section: Introductionmentioning

confidence: 99%

The Use of hCG for Inducing Ovulation in Sheep Estrus Synchronization Impairs Ovulatory Follicle Growth and Fertility

Cano-Moreno

Lago-Cruz²,

Encinas³

et al. 2021

Animals

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“…One half (containing 1.5 mg norgestomet) was implanted subcutaneously in the ear of each ewe. At the time of implant removal, 400 IU of eCG (Folligon; Intervet) and 22.5 μg D-cloprostenol (Preloban; Intervet) were injected intramuscularly into every ewe and AI 0.5 ml semen 20 .…”

Section: Resultsmentioning

confidence: 99%

The Effects of Model IVS 2 MAP Progesterone, eCG, GnRH, and PGf2? on Pregnancy of Tail Fat Ewes Strain Sapudi Islands Subjected to A Short-term Synchronization of Estrus

Hermadi¹,

Hariadi²,

Ratnani³

2020

MLU

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The objective of this study was to verify the effects of engineering design of IVS 2 progesterone with 2 cm thick sponge and 2 cm length and 5 cm silicon plate in the middle with 13 cm nylon cord ties to pull the sponge position. Try to determine the effective dose of progesterone (MAP) with a dose of 60 mg progesterone, eCG, GnRH and PGf2α on pregnancy of ewes subjected to a short-term synchronization of estrus. Tail fat sheep ewes strain sapudi Islands received 60 mg MAP sponges model IVS 2 during 12 days plus 500 IU eCG folligon and 2.5 mg d-cloprostenol capriglandin (0.5 ml) submucosa vulva 24 h prior to IVS 2. Control groups (T0) 10 Ewes were assigned to receive 0.9% NaCl solution 2 ml im only when estrus sign showed waited for natural estrus. Group treatment 10 Ewes were (T1) IVS2 + 500 IU eCG folligon and group treatment 10 Ewes were (T2) IVS2 +500 IU eCG folligon 21.5 µg (0.5 ml) GnRH fertagyl gonadorelin, 24 hours after withdrawal. Each group was assigned to intracervical insemination by Vaginoscopy (n = 30). Artificial insemination was performed with a single dose of fresh semen on egg yolk skim milk dilluters. For controlled mating, females were exposed to males 48 hours after sponges removed. Ten females per treatment were subjected to transrectal ultrasound examination at 35 days late after AI. Estrous response (100.0%), pregnancy rates (T0 80% T1 70% and T2 70%), did not differ between T1 and T2 respectively (p >0.05). Administration of GnRH 24 hours after IVS 2 removed does not improve pregnancy rate in estrous synchronization in Tail fat ewes strain sapudi Islands (p >0.05) on day 35.

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“…Research efforts are focusing on finding alternative treatments to eCG administration in protocols to induce oestrus and ovulation in small ruminants [ 4 , 27 , 28 ] considering the concerns linked to its production for brood mare health and welfare [ 29 ]. The reduction in the use of synthetic hormones in livestock farming would also meet consumer demand for “natural, green, and clean” methods [ 30 ].…”

Section: Discussionmentioning

confidence: 99%

Towards a Sustainable Reproduction Management of Dairy Sheep: Glycerol-Based Formulations as Alternative to eCG in Milked Ewes Mated at the End of Anoestrus Period

Sotgiu

Porcu

Pasciu

et al. 2021

Animals

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This study investigated whether the administration of equine chorionic gonadotrophin (eCG) in a protocol to induce and synchronize ovulations before mating could be replaced by the administration of glycerol-based formulations in milked ewes at the end of their seasonal anoestrus. Forty-eight late-lactation dairy ewes of the Sarda breed were synchronized using sponges impregnated with progestogen and then joined with fertile rams (day (D) 0, ram introduction). From D−4 to D−1, the ewes received by gavage either 100 mL of a glucogenic mixture (70% glycerol, 20% propylene glycol and 10% water; GLU group; n = 24) or 100 mL of water (GON group; n = 24) twice daily. Moreover, on the day of sponge withdrawal (D−1), GON ewes received 200 IU of eCG. There were no differences in reproductive performances between groups. GLU ewes showed higher glycemia (p < 0.001), insulinemia (p < 0.05), plasma glycerol (p < 0.001), triglycerides (p < 0.001) and lower cholesterol (p < 0.001), non-esterified fatty acids (NEFA; p < 0.05) and urea (p < 0.001). Plasma osmolality was higher in GLU but only 4 h after dosing (p < 0.001). Milk yield and milk composition were not affected by the treatments with exception of milk glycerol (p < 0.001) and milk urea (p < 0.001), which were higher and lower in GLU than GON ewes, respectively. In conclusion, the administration of the glucogenic mixture to late lactation dairy ewes at the end of anoestrus period resulted in reproductive responses as good as the ones obtained by the eCG treatment, suggesting that the objective of a sustainable reproductive management of dairy sheep can be successfully pursued.

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Use of Propylene-Glycol as a Cosolvent for GnRH in Synchronization of Estrus and Ovulation in Sheep

Cited by 10 publications

References 31 publications

The Use of hCG for Inducing Ovulation in Sheep Estrus Synchronization Impairs Ovulatory Follicle Growth and Fertility

The Use of hCG for Inducing Ovulation in Sheep Estrus Synchronization Impairs Ovulatory Follicle Growth and Fertility

The Effects of Model IVS 2 MAP Progesterone, eCG, GnRH, and PGf2? on Pregnancy of Tail Fat Ewes Strain Sapudi Islands Subjected to A Short-term Synchronization of Estrus

Towards a Sustainable Reproduction Management of Dairy Sheep: Glycerol-Based Formulations as Alternative to eCG in Milked Ewes Mated at the End of Anoestrus Period

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