Efficacy of using previously used controlled internal drug release (CIDR) insert on the reproductive performance, hormone profiles and economic measures of sheep

Abstract

This study was conducted using 120 multiparous Awassi ewes during the breeding season to compare the effects of using previously used controlled internal drug release (CIDR) on the hormone profiles, reproductive performance and economic measures of ewes. Ewes were randomized to receive one of five previously used CIDR (previously used for 6, 12, 18, 24 or 30 days) or the new CIDR as a control for 6 days (CIDR6, CIDR12, CIDR18, CIDR24, CIDR30, and CIDR0 [control], respectively). Blood samples were collected on four occasions, at the time of CIDR insertion, after 3 days of insertion, and at the time of withdrawal and insemination. Serum estradiol (E2) and progesterone (P4) concentrations were measured. Timed insemination was performed 48 hr post-CIDR withdrawal. Pregnancy was diagnosed by ultrasonography 23 days after insemination and confirmed on day 35. The heat detection rate was significantly (p < 0.05) higher in the CIDR0 and CIDR6 groups than in the CIDR18 and CIDR30 groups. The total pregnancy rate and fecundity were significantly (p < 0.05) higher in the CIDR6 group than in other groups. P4 level was significantly (p < 0.05) higher in the CIDR0 group than in the CIDR30 group at the time of removal. At each time point, the E2 level was significantly (p < 0.05) higher in the CIDR6 group than at the other groups. The total variable cost, total cost, return and net profit were higher in the CIDR6 and CIDR0 groups than in the other groups. In conclusion, although previously used CIDRs are efficient at synchronizing oestrus in ewes, the duration of previously usage significantly affected the reproductive parameters and economic profit. CIDRs previously used for 6 days and new CIDRs provided the highest fertility and fecundity rates, besides return and net profit. Economically, it is not advisable to use CIDRs that previously used for 12 days or more.

Reusing intravaginal progesterone releasing devices for oestrous synchoronization in ewes

“…However, with the dose of 200 IU of eCG it tended (P =0.078) to increase (Table 1). The high percentage of ewes that showed oestrus behaviour (95.31%) in response to the reused CIDR suggests that in the second use CIDRs still contain enough P 4 to cause LH blockage and allow the brain to respond to concentrations of circulating oestradiol, so that Insertion of CIDR Removal of CIDR Administration of eCG oestrous behaviour can be induced in the female (Swelum et al, 2018b). Previous studies have shown that when associated with eCG and a luteolytic agent, use for the third time in short protocols is viable for the synchronization and induction of oestrus and ovulation in ewes without affecting the percentages of oestrus presentation (Pinna et al, 2012;Bazzan et al, 2013;Vilariño et al, 2013;Da Silva et al, 2014) since the eCG favours follicular growth and the consequent production of oestradiol (Murphy, 2012).…”

“…Elevation of serum P 4 concentration, which is influenced by the release of P 4 from the device, causes persistent follicle regression and inhibits the release of gonadotropins from the anterior pituitary gland, allowing blockage of oestrus behaviour and ovulation until withdrawal of the device (Swelum et al, 2018b). Subsequently, the inhibition disappears on the removal of the device, which causes the stimulation of the gonadotropin-releasing hormone pulse from the hypothalamus, which influences the preovulatory increase of LH and FSH that results in the re-start of ovarian activity, which culminates in ovulation (Laven, 2019;Martinez-Ros et al, 2019a).…”

“…However, they are costly compared with sponges, which limits their generalized use in commercial farms, and having to be disposed of after the first use causes environmental contamination owing to the residual hormone they contain (Biehl et al, 2019). For this reason, research has been conducted to determine the efficiency of induction and synchronization of oestrous with reused CIDRs in anoestrus sheep and during the reproductive season (Güngör et al, 2009;Pinna et al, 2012;Swelum et al, 2018b). Likewise, their use has been evaluated in short experiments (Cox et al, 2012;Vilariño et al, 2013;Bazzan et al, 2013) and for multiple times (Da Swelum et al, 2015;Swelum et al, 2018b).…”

“…For this reason, research has been conducted to determine the efficiency of induction and synchronization of oestrous with reused CIDRs in anoestrus sheep and during the reproductive season (Güngör et al, 2009;Pinna et al, 2012;Swelum et al, 2018b). Likewise, their use has been evaluated in short experiments (Cox et al, 2012;Vilariño et al, 2013;Bazzan et al, 2013) and for multiple times (Da Swelum et al, 2015;Swelum et al, 2018b). The devices seem to be effective in the second or third use, mainly when combined with eCG.…”

Induction of fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes

“…The importance of adequate P4 concentrations during the preceding luteal phase for estrus expression is suggested, for example, by reports that estrus expression is reduced after synchronization with previously used controlled internal drug releasing (CIDRs) devices, which results in lower than normal P4 concentrations during the treatment [28,29]. However, if in the present study the differences in estrus expression between groups were related to differences in P4 concentrations during the preceding luteal phases, these differences must have been very subtle, because the general P4 profile and the average duration of the luteal phases were similar in all groups.…”