Data/hora: 22/06/2024 11:12:54

Biblioteca(s): 	Embrapa Rondônia.	
Data corrente: 	02/06/2022	
Data da última atualização: 	02/06/2022	
Autoria: 	PFEIFER, L. F. M.; GASPERIN, B. G.; CESTARO, J. P.; SCHNEIDER, A.	
Afiliação: 	LUIZ FRANCISCO MACHADO PFEIFER, CPAF-RO; B. G. GASPERIN, Universidade Federal de Pelotas (UFPel); J. P. CESTARO, Universidade Federal do Acre (Ufac); A. SCHNEIDER, Universidade Federal de Pelotas (UFPel).	
Título: 	Postponing TAI in beef cows with small preovulatory follicles.	
Ano de publicação: 	2022	
Fonte/Imprenta: 	Animal Reproduction Science, v. 242, 107006, 2022.	
ISSN: 	0378-4320	
DOI: 	https://doi.org/10.1016/j.anireprosci.2022.107006	
Idioma: 	Inglês	
Conteúdo: 	The aims of this study were (1) to establish an optimal cut-off point for evaluating the effect of the preovulatory follicle (POF) diameter in timed AI (TAI) programs, and (2) to evaluate the effect of postponing TAI in cows with smaller follicles on pregnancy per AI (P/AI). In Study 1, Nelore cows (n = 426) were subjected to an estradiol-progesterone (P4) based TAI protocol. The diameter of POF was measured at TAI, 48 h after P4 insert removal. From the ROC curves for determining the relationship between the POF diameter and pregnancy, the cut-off was 11 mm (P < 0.001). Cows with larger POF had greater (P < 0.05) P/AI (62.5%) than cows with smaller POF (34.8%). In Study 2, Nelore cows (n = 1257) were subjected to the same TAI protocol as in Study 1. Before TAI, cows were separated according to POF diameter in three groups: (1) Larger POF (LP, n = 873; POF &#8805;11 mm), (2) Smaller POF 0 h (SP0, n = 195; POF <11 mm), and (3) Smaller POF 24 h (SP24, n = 189; POF <11 mm). Cows in the LP and SP0 were TAI at 48 h and cows in the SP24 group were TAI at 72 h after P4 insert removal. Cows in the LP group had the greatest (P < 0.05) P/AI (60.25%), followed by cows in the SP24 group (41.8%), while cows in the SP0 group had the lowest P/AI (31.8%). In conclusion, cows with smaller follicles have lower P/AI, but postponing the TAI by 24 h in these cows increases P/AI.	
Palavras-Chave: 	Diâmetro do folículo; Folículos pré-ovulatórios; Follicular diameter; Preovulatory follicles.	
Thesagro: 	Ovulação; Reprodução Animal; Vaca de Corte.	
Thesaurus Nal: 	Animal reproduction; Beef cows; Ovulation.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
URL: 	http://ainfo.cnptia.embrapa.br/digital/bitstream/doc/1143679/1/cpafro-18765.pdf	
Registro original: 	Embrapa Rondônia (CPAF-RO)	
Exemplares: 	CPAF-RO - (18765-1) - UPC - AP - DD -  -  -  - DIS