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da Silva FP, Neves KAL, Correa FRA, Silva LKX, Batista HR, da Silva WC, Mercado Caruso N, Minervino AHH. Follicular Dynamics and Pregnancy Rate in Nellore Heifers Submitted to Fixed-Time Artificial Insemination Protocols (FTAI). Vet Sci 2022; 9:377. [PMID: 35893770 PMCID: PMC9332594 DOI: 10.3390/vetsci9080377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 07/12/2022] [Accepted: 07/20/2022] [Indexed: 11/28/2022] Open
Abstract
This study aimed to evaluate follicular dynamics and pregnancy rates in Nellore heifers submitted to fixed-time artificial insemination (FTAI) protocols associated with equine chorionic gonadotrophin (eCG) or follicle stimulating hormone (FSH). Nellore heifers (n = 259) were used, divided into two studies. Experiment I evaluated the ovarian follicular dynamics in 64 Nellore heifers submitted to different FTAI protocols (n = 32/group) using either FSH or eCG. In Experiment II, the pregnancy rate was evaluated in 195 heifers submitted to FTAI protocols and divided into two groups: FSH (n = 97) and eCG (n = 98). In Experiment I, the ultrasound examination showed that the maximum diameter of the dominant and preovulatory follicles and the ovulation time were similar between the FSH and eCG groups (p > 0.05). However, the ovulation rate was higher in the eCG group when compared to FSH (p = 0.014). In Experiment II, females that received eCG presented a higher pregnancy rate (58.1%) when compared to FSH (40.2%) (p = 0.012). The use of eCG in the FTAI protocol in Nellore heifers promoted a higher ovulation rate and increased pregnancy rate and may be the most suitable alternative to increase conception rates in animals that are raised in an extensive system under tropical conditions in the Amazon.
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Affiliation(s)
- Filipe Prudente da Silva
- Centro Universitário da Amazônia, Santarém 68010-200, PA, Brazil; (F.P.d.S.); (F.R.A.C.); (L.K.X.S.); (H.R.B.); (W.C.d.S.)
| | - Kedson Alessandri Lobo Neves
- Laboratory of Animal Health (LARSANA), Federal University of Western Pará (UFOPA), Rua Vera Paz, s/n, Salé, Santarém 68040-255, PA, Brazil;
| | - Francisco R. A. Correa
- Centro Universitário da Amazônia, Santarém 68010-200, PA, Brazil; (F.P.d.S.); (F.R.A.C.); (L.K.X.S.); (H.R.B.); (W.C.d.S.)
| | - Lílian K. X. Silva
- Centro Universitário da Amazônia, Santarém 68010-200, PA, Brazil; (F.P.d.S.); (F.R.A.C.); (L.K.X.S.); (H.R.B.); (W.C.d.S.)
| | - Helder R. Batista
- Centro Universitário da Amazônia, Santarém 68010-200, PA, Brazil; (F.P.d.S.); (F.R.A.C.); (L.K.X.S.); (H.R.B.); (W.C.d.S.)
| | - Welligton C. da Silva
- Centro Universitário da Amazônia, Santarém 68010-200, PA, Brazil; (F.P.d.S.); (F.R.A.C.); (L.K.X.S.); (H.R.B.); (W.C.d.S.)
| | - Nohora Mercado Caruso
- Departamento Productividad e Innovación, Universidad de la Costa, CUC, Calle 58 n.55-66, Barranquilla 080001, Atlántico, Colombia;
| | - Antonio Humberto Hamad Minervino
- Laboratory of Animal Health (LARSANA), Federal University of Western Pará (UFOPA), Rua Vera Paz, s/n, Salé, Santarém 68040-255, PA, Brazil;
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