Hormonal protocols for the synchronization and induction of synchronized estrus in dairy ewes kept under tropical conditions
Lombardo, Higor Nascimento Silva; Monteiro, Clara Ana Santos; Delgado, Karina Frensel; Pinna, Aline Emerim; Vasconcelos, Carlos Otávio de Paula; Nogueira, Luiz Altamiro Garcia; Brandão, Felipe Zandonadi; Balaro, Mario Felipe Alvarez.
Acta sci. vet. (Impr.)
; 48: Pub.1751-Jan. 30, 2020. tab
Artículo
en Inglés
| VETINDEX | ID: biblio-1458274
Background:
Lacaune is an important sheep breed and shows reproductive seasonality which affects dairy product supply. The most common hormonal protocols are based on progesterone-releasing devices in order to reach reproductive activity. Due to international consumer demand for natural, green, and clean methods, such issues encourage the minimal or absent use of synthetic hormones in livestock. In this sense, the present study tested the efficiency of induction and estrus synchronization protocols in lacaune ewes, considering application interval of synthetic prostaglandin at the breeding season; length of synthetic progesterone exposure; and eCG dose at the outbreeding season. Materials, Methods &Results:
In study 1 52 ewes were submitted to estrus synchronization protocol using two doses of d-cloprostenol 7 or 9 days apart. In study 2 47 ewes were submitted to estrus induction protocol using an intravaginal device containing 60 mg of medroxyprogesterone acetate maintained for 6, 9, or 12 days. In study 3 46 ewes were submitted to synchronized estrus induction protocol using intravaginal progesterone device for six days. On the fifth day, d-cloprostenol and 300 IU or 400 IU of eCG were administered. For all studies, signs of estrus beginning/ending were recorded and natural mating was performed. After 30 days, transrectal ultrasound was performed for pregnancy diagnosis. In study 1, groups presented similar rate of estrus behavior (78.8%) and pregnancy (average 75.6%). Meanwhile, compared to G9days (37.8 ± 7.2 h), interval between the second dose of prostaglandin and beginning of estrus was smaller in G7days (31.5 ± 7.8 h). No difference was found among variables studied in study 2 (P > 0.05), nevertheless the SD for the estrus duration was shorter (P < 0.05) in G6days and G12 days when compared with the G9days . Equally, the SD...
Biblioteca responsable:
BR68.1
Ubicación: BR68.1
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