Histrelin acetate-induced ovulation in Brazilian Northeastern jennies (Equus asinus) with different follicle diameters

• Autor(a) principal: de Oliveira, Sidnei Nunes [UNESP]
• Data de Publicação: 2019
• Outros Autores: Canuto, Lucas [UNESP], Segabinazzi, Lorenzo Garrido Teixeira M. [UNESP], Dell´Aqua Junior, Jose Antonio [UNESP], Papa, Patricia [UNESP], Fonseca, Mariana [UNESP], Ribeiro Filho, Antonio de Lisboa, Papa, Frederico [UNESP]
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.theriogenology.2019.06.037; http://hdl.handle.net/11449/190433
• topic: Cycle manipulation; Donkeys; GnRH; Reproduction

The aim of the present study was to evaluate the efficacy of a GnRH analog for induction of ovulation in Brazilian Northeastern jennies (Equus asinus) with different follicle diameters. Four consecutive estrus of 10 jennies were used in a crossover study; C (Control, n = 10) jennies were evaluated by transrectal palpation and ultrasonography until a spontaneous ovulation and the intervals between the predetermined follicular size (25–28 mm [C1], 29–32 mm [C2] and 33–36 mm [C3] follicle) and ovulation were registered. In treated cycle, jennies had the ovulation induced by 250 μg of Histrelin acetate (Strelin®, Botupharma, Botucatu, Brazil) when respective follicle diameters 25–28 mm (T1), 29–32 mm (T2) and 33–36 mm (T3) were diagnosed. Ovulation was monitored by transrectal palpation and ultrasonography. Different follicle diameters significantly affected (P < 0.05) the interval until ovulation between control and matched treated cycles. Interval between prostaglandin administration and ovulation diagnosis was lower in jennies from T2 group (145.2 ± 34.6 h) compared with the control cycle (220.0 ± 41.8 h) and also with other treated cycles (T1 - 209.8 ± 48.0 h; T3 – 183.3 ± 33.9 h). Histrelin acetate treatment also reduces the interval between detection of predetermined follicular size and ovulation (P < 0.05) in all treated cycles groups compared with matched control group. Higher percentage (P < 0.05) of jennies had success of ovulation induction (36–48 h after Histrelin acetate injection) in all treated cycles in contrast with the matched control group. In addition, in comparison among treated cycle groups, more (P < 0.05) jennies (100%) in T2 ovulated between 36 and 48 h after ovulation induction, compared with T1 and T3, which did not differ (P > 0.05) from each other. Edema scoring and ovulation were not associated events (r = 0.0219). In conclusion, jennies with 29–32 mm follicles satisfactory responded to ovulation induction with Histrelin acetate, which allowed the shortening of interovulatory interval in all groups evaluated.