The Induction and Synchronization of Estrus in Meat Goats during the Fall and Late Spring (season and out-of-season) Using Controlled Internal Drug Release (CIDR) Devices on Delmarva.

Changes in USA’s demographics have increased chèvon (goat meat) demand. USDA/NASS reported annual chèvon imports >$129 million. During the year, demand follows traditions and festivals which change from year-to-year. It is challenging for meat-goat producers to cater to consumer demand because goats are seasonal breeders. USA-FDA approved CIDRs (2009) for sheep estrus synchronization; however, FDA’s approval of CIDRs for goats is still pending. This demonstration’s objective was not to determine CIDRs efficacy in meat-goats, but to resolve applicability and practicality of CIDR use to reduce kidding periods and target peak chèvon demands. From 2012 to 2015, crossbred does (n=183) were separated into two groups, synchronized (CIDR) or not (CONTROL), for breeding in late Spring (anestrus-season) or Fall (natural-breeding-season). At each breeding event, CIDRs were inserted for 12 to 18 d. At the time of CIDR removal, does were clustered in single buck mating groups of no more than 6 does/group. The goat protocol proposed for FDA approval (12 to 18 d) was followed because pre-trials at this station gave inconsistent results following the sheep’s label CIDRs insertion and removal time (5 d). At birth, goat-kids were tagged, weighed, sexed and litter size was recorded (LSZ; kids/doe exposed). Data was analyzed using Chi-square and ANOVA (SAS software package) for the effect of synchronization and season on pregnancy rates (PR) (pregnant does/exposed does) and LSZ at birth. Overall, PR did not differ from one year to the other in CIDR or CONTROL does. Also, during the trial, PRs were similar in CIDR does and in CONTROL does (40.6% and 30.0%, respectively). PRs did not differ in Spring (17.8% and 19.5% for CIDR and CONTROL respectively); but PRs were significantly different (P < 0.03) in Fall for CIDR and CONTROL does (60.8% and 39.1%, respectively). Overall, doe LSZ was influenced by season bred and use of CIDRs; with CIDR-Fall -bred does having a higher (P <0.0001) LSZ (1.6 ± 0.2) compared to CONTROL-Fall, CONTROL- Spring, and CIDR-Spring bred does (0.8 ± 0.2, 0.4 ± 0.2 and 0.4 ± 0.2, respectively). These results do not encourage the use of CIDRs in commercial meat-goat herds for increasing pregnancy rates. Further targeted studies will be useful to confirm LSZ increase in fall bred CIDR does. CIDR synchronization in our station reduced a 60 to 90 d kidding period to 10 d allowing operators to arrange facilities, labor and supplies accordingly, enhancing kid survival and does welfare.