Abstract
ABSTRACT Fifty-seven multiparous Awassi ewes in the breeding season were used to compare the effects of controlled internal drug release (CIDR) reuse on hormone profiles, reproductive performance, and economic production. Ewes were randomly allotted to one of three CIDR treatments: new (control), once-used, and twice-used; treatment lasted 12 days. Blood samples were collected from all groups at the time of CIDR insertion, three and six days following insertion, at withdrawal time, and at insemination. Serum estradiol (E2) and progesterone (P4) concentrations were measured. Timed insemination was performed 48 h post CIDR withdrawal in all groups. Pregnancy was diagnosed by ultrasonography at day 23 post insemination. No significant differences were detected among groups in pregnancy rate/ewes in heat, twinning rate, fecundity, abortion rate, and prolificacy. However, estrus detection rate was significantly higher in control (100%) than in other groups. The P4 concentration was significantly higher in control than in other groups during treatment period; at insemination, P4 concentration was significantly higher in control than in other groups; at insemination time, E2 concentration was significantly higher in control than in the other groups; and the net profit was higher in once-used than in other groups. One-time reuse of CIDR for the long term (12 days) can synchronize estrus in ewes efficiently with higher net profit than the new or twice-used CIDR.
Highlights
Estrus synchronization enhances reproductive efficiency and allows the selection of parturition times, which improves production efficiency (Whitley and Jackson, 2004)
Fifty-seven multiparous Awassi ewes in the breeding season were used to compare the effects of controlled internal drug release (CIDR) reuse on hormone profiles, reproductive performance, and economic production
The P4 concentration was significantly higher in control than in other groups during treatment period; at insemination, P4 concentration was significantly higher in control than in other groups; at insemination time, E2 concentration was significantly higher in control than in the other groups; and the net profit was higher in once-used than in other groups
Summary
Estrus synchronization enhances reproductive efficiency and allows the selection of parturition times, which improves production efficiency (Whitley and Jackson, 2004). Sheep producers gradually adopt synchronization protocols because of the difficulties associated with estrus detection. Several studies have focused on using blind fixed-time insemination after hormonal treatment in sheep (Fukui et al, 1999). The most efficient hormonal treatments in ovine reproduction programs use intravaginal devices (silicone or polyurethane sponges) impregnated with progesterone (P4) or other progestogens (Abecia et al, 2011; Swelum et al, 2014). Sponges are generally less costly than silicone (Wheaton et al, 1993), their use can result in greater vaginitis and drawstring breakage rates (Romano, 2004). Changes in vaginal flora associated with sponges can negatively affect the sexual attraction of ewes in estrus (Gatti and Ungerfeld, 2012)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
