Data/hora: 05/06/2024 16:10:26

Biblioteca(s): 	Embrapa Pantanal.	
Tipo da produção científica: 	Artigo em Periódico Indexado	
Circulação/Nível: 	A - 1	
Data corrente: 	26/11/2018	
Data da última atualização: 	18/11/2019	
Autoria: 	RODRIGUES, W. B.; SILVA, A. S.; SILVA, J. C. B.; ANACHE, N. A.; SILVA, K. C. da; CARDOSO, C. J. T.; GARCIA, W. R.; SUTOVSKY, P.; NOGUEIRA, E.	
Afiliação: 	W. B. RODRIGUES, MELHORE ANIMAL CONSULTORIA LTDA; A. S. SILVA, GENESIS TECNOLOGIA E REPRODUÇÃO ANIMAL; JULIANA CORREA BORGES SILVA, CPAP; NATALIA ALBANESE ANACHE, UFMS; KARINE CASANOVA DA SILVA, UFMS; C. J. T. CARDOSO, UFMS; W. R. GARCIA, UFMS; P. SUTOVSKY, UNIVERSITY OF MISSOURI; ERIKLIS NOGUEIRA, CPAP.	
Título: 	Timed artificial insemination plus heat II: gonadorelin injection in cows with low estrus expression scores increased pregnancy in progesterone/estradiol-based protocol.	
Ano de publicação: 	2019	
Fonte/Imprenta: 	Animal, v. 13, n. 10, p. 2313-2318, 2019.	
DOI: 	10.1017/S1751731119000454	
Idioma: 	Inglês	
Conteúdo: 	The use of tail chalk and estrus/heat expression scores (HEATSC) evaluation is instrumental in identifying cows with greater estrus expression and greater artificial insemination pregnancy rates (P/AI) in cows submitted to timed artificial insemination (TAI), and cows with low or no estrus expression present lower P/AI. It was intended in this study to improve the pregnancy rates in TAI for Bos indicus beef cows, and gonadotrophin-releasing hormone (GnRH) injection was hypothesized to increase pregnancy rates in a TAI program for cows submitted to progesterone?estradiol-based protocols with low or no estrus expression, evaluated by HEATSC. Cows (n= 2284) received a progesterone device and 2mg estradiol benzoate, after 8 days the device was removed and 1 mg estradiol cypionate, 150?g of D-cloprostenol and 300 IU equine chorionic gonadotropin was administered. All cows were marked with chalk and HEATSC evaluated (scales 1 to 3) at TAI performed on day 10. Animals with HEATSC1 and HEATSC2 ( n= 937) received 100?g de gonadorelin (GNRH group; n= 470), or 1ml saline (Control group; n= 467), and cows with HEATSC3 (named HEAT group; n= 1347) received no additional treatment. The larger dominant follicle, evaluated on day 8and at TAI (day 10), was greater in HEAT group ( P= 0.0145 and P <0.001, respectively). Corpus luteum (CL) area and progesterone concentration was evaluated on day 17, and CL area was larger in HEAT group, intermediary in Control and lower in GnRH group (Control= 2.68 cm2, GnRH= 2.37 cm2, HEAT group= 3.07 cm2, P <0.001). Greater progesterone concentrations were found in HEAT group than in Control and GnRH groups (Control= 4.74 ng/ml, GnRH= 4.29 ng/ml, HEAT group= 6.08 ng/ml, P<0.001). There was a difference in ovulation rate, greater in HEAT group than GnRH and Control groups (Control= 72.5%; GnRH= 81.25%; HEAT group= 90.71%; P= 0.0024). Artificial insemination pregnancy rates was greater in HEAT group (57.09% (769/1347) than in Control and GNRH groups, with positive effect of GnRH injection at the time of TAI in P/AI (Control= 36.18% (169/467), GnRH= 45.95% (216/470); P<0.0001). In conclusion, GnRH application in cows with low HEATSC (1 and 2) is a simple strategy, requiring no changes in TAI management to increase pregnancy rates in postpartum beef cows submitted to progesterone?estradiol-based TAI protocols, without reaching, however, the pregnancy rates of cows that demonstrate high estrus expression at the TAI.	
Palavras-Chave: 	Fertility; Follicle; Management.	
Thesagro: 	Jacaré.	
Thesaurus Nal: 	Artificial insemination; Caiman yacare; Paleosuchus palpebrosus; Reproduction.	
Categoria do assunto: 	G Melhoramento Genético	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (60277-1) - UPC - AP - DD -  -  -  - DIS