<p>The objectives of this study were to compare the effects of two intravaginal devices (ID) containing the same dose (0.5 g) of progesterone (P₄) on subsequent ovarian response, embryo production and circulating P₄ concentration profile in llamas (Lama glama) treated with equine chorionic gonadotropin (eCG) for ovarian superstimulation. Female llamas were randomly assigned (n = 10 llamas per group) to one of the following groups and treated (Day 0) with an ID containing

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... 5 g of vegetal P₄ to synchronize the emergence of a new follicular wave: i) DIB 0.5^® and ii) Cronipres M15^®. On Day 3 llamas were intramuscularly treated with 1000 IU of eCG. The IDs were removed on Day 7. Llamas were naturally mated (Day 9) and treated with GnRH analogue to induce ovulation. A second mating was allowed 24 h later. Embryos were collected between 7 and 8 days after the first mating. Blood samples were taken every day from Day 0 to Day 7 to measure circulating P₄concentrations. The results indicated that DIB device maintained greater plasma P₄ levels as compared to Cronipres until Day 2. However, the mean (± SD) number of corpora lutea and recovered embryos was not affected (p &lt; 0.05) by the type of ID (5.3 ± 2.6 vs 4.2 ± 2.2 and 3.5 ± 2.7 vs 2.6 ± 3.0 for DIB and Cronipres, respectively). In conclusion, both DIB and Cronipres devices can be successfully used to synchronize the emergence of follicular wave prior to a single dose of eCG in superovulation protocol in llamas.</p>