The Use of Melengestrol Acetate as a Strategy to Improve Production Efficiency of Sheep in Rural Areas in Mexico

Rojo-Martínez, Jesus Antonio; Salas-Razo, Guillermo

doi:10.17265/2161-6256/2015.03.009

Cited by 1 publication

(1 citation statement)

References 2 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pendleton et al (1992) compared the ability of a fluorogestone acetate (FGA) sponge to induce estrus and ovulation in anestrous dairy goats to that of implants containing Norgestomet and concluded that both were equally effective as part of the induction protocol. In small ruminants, the use of such progestogens, such as melengestrol acetate and fluorogestone for these purposes is well-established (Powell et al, 1996;Riesenberg et al, 2001;Rojo-Martínez and Salas-Razo, 2015;Rojo-Martínez et al, 2017). According to Cline at al.…”

Section: Discussionmentioning

confidence: 99%

Effectiveness of a low-dose Norgestomet ear implant in short-term protocols to induce estrus in ewes during the non-breeding season in Brazil.

et al. 2019

View full text Add to dashboard Cite

The objective of this study was to evaluate the reproductive performance of ewes subjected to a short-term protocol for estrus induction using 1 mg of Norgestomet during the non-breeding season in Brazil. A total of 84 ewes were randomly divided into two equal groups (n = 42 per group). Controlled Internal Drug Release (CIDR) containing 330 mg progesterone was inserted into the vagina in the first 42 ewes, and for the other 42 ewes in the second group, 1 mg of Norgestomet was placed subcutaneously in the convex surface of the ear. Implants and devices were removed in both groups on day 6. Following the removal of implants and devices, 10 mg of PGF2α and 300 IU of eCG were injected in all the ewes. After 48 h of application, three fertile rams were added to the herd. Ewes and rams were kept together for four days. Rams were removed on day 12, and after 42 days, pregnancy was diagnosed by ultrasound scanning. Short-term protocols using either an intravaginal device or ear implant were similarly effective to estrus induction (95.23 vs. 92.85%), and all ewes from both groups had estrus manifestation within 72 h after implant removal (72±9 h). In addition, no significant difference in pregnancy rate was observed between ewes treated with the intravaginal device and ear implant protocols (52.38 vs. 57.14%). These results suggest that 1 mg of Norgestomet is a good alternative for short-term protocols for estrus induction/ synchronization during the non-breeding season in ewes. It is possible to replace the progesterone-releasing intravaginal device by the ear implant and obtain the same reproductive effectiveness in ewes.

show abstract