Data/hora: 23/09/2024 15:56:35

Biblioteca(s): 	Embrapa Caprinos e Ovinos.	
Data corrente: 	25/10/2021	
Data da última atualização: 	10/12/2021	
Autoria: 	ROCHA, M. S.; MAIA, A. L. R. S.; RANGEL, P. S. C.; TAVARES, L. M.; OLIVEIRA, M. E. F.; FONSECA, J. F. da; OLIVEIRA, C. A.; SOUZA-FABJAN, J. M. G.	
Afiliação: 	M. S. ROCHA, Universidade de São Paulo - São Paulo, SP, Brazil; A. L. R. S. MAIA, Universidade Federal Fluminense - Niterói, RJ, Brazil; P. S. C. RANGEL, Unigranrio - Duque de Caxias, RJ, Brazil; L. M. TAVARES, Universidade Paulista - São José dos Campos, SP, Brazil; M. E. F. OLIVEIRA, Universidade Estadual Paulista - Jaboticabal, SP, Brazil; JEFERSON FERREIRA DA FONSECA, CNPC; C. A. OLIVEIRA, Universidade de São Paulo - São Paulo, SP, Brazil; J. M. G. SOUZA-FABJAN, Universidade Federal Fluminense - Niterói, RJ, Brazil.	
Título: 	Occurrence of early regression of corpora lutea in Dorper ewes subjected to a conventional superovulatory regimen.	
Ano de publicação: 	2021	
Fonte/Imprenta: 	Reproduction, Fertility, and Development, v. 33, n. 2, p. 146, 2021. Edição dos Proceedings of the 47th Annual Conference of the International Embryo Technology (IETS) Virtual Meeting, January 18-21, 2021.	
Idioma: 	Inglês	
Conteúdo: 	The early regression of corpora lutea (ERCL) is a functional alteration that occurs more often in animals subjected to multiple ovulation followed by embryo transfer (MOET) technique. Although it is mainly reported in goats, sheep are also susceptible to this disorder. The ERCL may compromise the quality and viability of embryos, and even embryonic recovery rate. Thus, the non-diffusion of the animal genetic material on a commercial scale increases costs, decreasing efficiency. This study aimed to assess the occurrence of ERCL in embryo donor ewes subjected to the MOET programs in different seasons. The research was carried out in a commercial herd in São Luís do Paraitinga city (23°22?S and 45°26?W), Brazil, over 4 years (2017?2020). Forty-four Dorper multiparous ewes aged between 3 and 9 years old and with body condition score (BCS) between 2 and 4.5 (1 to 5 scale) were used. Each ewe was used at least once for MOET and a maximum of 5 times, totalling 104 procedures. Regardless of the day of the oestrous cycle or anovulatory period (Day 0), ewes received a conventional superovulatory protocol consisting of an intravaginal device treatment with 0.33mg of progesterone (CIDR®, Zoetis). On Day 7, the device was replaced with a new one and ewes administered i.m. 0.24mg of sodium cloprostenol (Sincrocio®, Ourofino). The superovulatory treatment [256mg of FSH (Folltropin®, Vetoquinol)] started on Day 12 and consisted of decreasing doses (20, 20, 15, 15, 10, 10, 5, and 5%) administered intramuscularly (IM) every 12h for 4 days plus 200IU of equine chorionic gonadotrophin (eCG, Novormon®, Zoetis) at device removal on Day 14 and 0.1mg of gonadotrophin-releasing hormone (Fertagyl®, MSD) IM 1 day later (Day 15). Laparoscopic AI was performed twice on Day 16 using cooled semen. Five days after AI, ovaries were assessed by laparoscopy to check the presence and viability of corpora lutea (CL). Ewes that had avascular CL (pinkish to whitish colour) were classified as ERCL and embryo collection was not performed. The occurrence of ERCL in each season and category of BCS was checked by either chi-squared or Fisher test. Logistic regression was performed according to the incidence of ERCL in each category of age. Values of P<0.05 were considered as significant. From 104 procedures, ERCL was identified in 26 cases, totalling 25% of occurrence. The proportion of occurrence did not differ (P>0.05) among seasons: breeding (10/43: 23%), transition (10/36, 28%), or anoestrous (6/25, 24%). There was no difference in ERCL incidence in ewes presenting different BCS categories: lower/thin (2 to 2.5: 3/12, 25%); average/good (3 to 3.5: 15/66, 22%) and higher/fat (4 to 4.5: 8/26, 31%). Indeed, there was no association (P>0.05) between ERCL and age. In conclusion, a relevant occurrence of ERCL was detected in superovulated embryo donor ewes but this incidence was not associated with season, age, or BCS of Dorper ewes. These data highlight the importance of pharmacological measures to control ERCL in MOET protocols for commercial sheep herds.	
Thesagro: 	Ciclo Estral; Gonadotrofina; Ovino; Progesterona; Reprodução Animal; Sêmen; Sódio; Superovulação.	
Thesaurus Nal: 	Animal reproduction; Anovulation; Body condition; Brazil; Cloprostenol; Color; Corpus luteum; Dorper; Embryo transfer; Equine chorionic gonadotropin; Estrous cycle; Ewes; Gonadotropin-releasing hormone; Herds; Intravaginal devices; Laparoscopy; Progesterone; Regression analysis; Sheep; Sodium; Superovulation; Viability.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Caprinos e Ovinos (CNPC)	
Exemplares: 	CNPC - (39884-1) - UPC - RA - DD -  -  -  - DIS