The ovarian and uterine responses of Baixadeiro mares to prostaglandin synchronization during the dry and rainy seasons.

Luciana Cordeiro Rosa,Adriana Raquel De Almeida Da Anunciação,Luiz Bruno Oliveira Chung,Ricardo De Macêdo Chaves,Fernando Andrade Souza,Felipe Lucas Correa Pereira,Renatta Silva Melo,Eliane Cristina Silva Dias,Carla Janaína Rebouças Marques Do Rosário,Felipe De Jesus Moraes Junior

doi:10.1590/1984-3143-ar2020-0050

Luciana Cordeiro Rosa, Adriana Raquel De Almeida Da Anunciação + Show 8 more

Open Access

https://doi.org/10.1590/1984-3143-ar2020-0050

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Abstract

This study aimed to evaluate the effect of synchronization with prostaglandin F2α in Baixadeiro mares during the rainy and dry seasons. Fourteen mares were synchronized by administering two doses of 1 mL prostaglandin PGF 2α and monitored by rectal palpation and ultrasound for the assessment of follicular development and uterine echotexture. Of this total, nine mares allowed the collection of blood, in which the blood was collected by venipuncture of the jugular vein to determine progesterone (P4) by ELISA. Mares showed no differences (P > 0.05) in weight, body score condition (BSC), tone, uterine edema, frequency of ovulation, synchronization interval, estrus, and the total number of follicles between periods. However, there was a difference in large increased follicle diameter (P < 0.05) during the dry season. The average concentrations of P4 in mares differed (P < 0.05) between the pre- and post-ovulatory phases for both seasons and after ovulation, with higher concentrations in the rainy season. Furthermore, statistical differences in daily light (P < 0.05) were observed between the dry and rainy periods. Thus, we conclude that mares from the genetic grouping Baixadeiro showed no reproductive seasonality, though there was a difference in luminosity between the rainy and dry seasons. The treatment with two doses of PGF 2α was effective in synchronizing the mares, promoting the return of estrus in the dry and rainy periods. The mares remaining cyclically active throughout the year provided there were appropriate forage availability and quality levels to allow for normal values of body weight and condition.

Highlights

The "Baixadeiro" horse consists of a breed of native horses, typical of the Baixada Maranhense region, bred in the wilderness and acknowledged for their rusticity, physical strength as workhorses and resistant to dwelling on vast flat areas of flooded fields during the rainy season and cracked soil in the dry period
As for tonus and edema, changes were observed throughout the estrus, in which ovulating mares showed minimal tonus and a higher degree of edematous close to ovulation (Figure 2)
There was no statistical difference between RS and DS for the total number of follicles between days 0 (6.57 ± 2.63 and 4.85 ± 2.13), days 7 (6.50 ± 3.28 and 6.85 ± 3.62 and day 14 (8.00 ± 2.23 and 7.28 ± 3.49), these are in agreement with the number of expected follicles during follicular wave emergence and are independent of body condition

Summary

Introduction

The "Baixadeiro" horse consists of a breed of native horses, typical of the Baixada Maranhense region, bred in the wilderness and acknowledged for their rusticity, physical strength as workhorses and resistant to dwelling on vast flat areas of flooded fields during the rainy season and cracked soil in the dry period. This racial group is small, with a predominant light gray or chestnut coats resulting from crossbreeding breeds introduced from the Iberian Peninsula (Gazolla et al, 2009).

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