Data/hora: 23/06/2024 13:02:25

Biblioteca(s): | Embrapa Pantanal.
Tipo da produção científica: | Artigo em Periódico Indexado
Circulação/Nível: | A - 2
Data corrente: | 24/11/2016
Data da última atualização: | 24/11/2016
Autoria: | PUGLIESI, G.; SANTOS, F. B.; LOPES, E.; NOGUEIRA, E.; MAIO, J. R. G.; BINELLI, M.
Afiliação: | G. PUGLIESI, University of São Paulo; F. B. SANTOS, UNIVERSITY OF SÃO PAULO; E. LOPES, UNIVERSITY OF SÃO PAULO; ERIKLIS NOGUEIRA, CPAP; J. R. G. MAIO, OURO FINO SAÚDE ANIMAL; M. BINELLI., UNIVERSITY OF SÃO PAULO.
Título: | Improved fertility in suckled beef cows ovulating large follicles or supplemented with long-acting progesterone after timed-AI.
Ano de publicação: | 2016
Fonte/Imprenta: | Theriogenology, n. 85, n. 7, p. 1239-1248, April 2016.
Idioma: | Inglês
Conteúdo: | We aimed to evaluate the effects and the interaction of size of the preovulatory follicle (POF) and long-acting progesterone (P4) supplementation after timed-AI on CL function and pregnancy success in beef cows. In experiment 1, ovulations of beef cows were synchronized starting on Day 10, and cows were split to receive sodium cloprostenol (large follicle group; LF; n ¼ 31) or nothing (small follicle group; SF; n ¼ 35). Ovulations were induced on Day 0, and cows were inseminated. Ovulated cows were assigned to receive placebo (LF/control group, n ¼ 14; and SF/control group, n ¼ 9) or 150 mg of long-acting P4 on Day 4.5 (LF/P4 group, n ¼ 13; and SF/P4 group, n ¼ 12). Diameter of POF, blood flow in POF wall, ovulation rate, and size and vascularization of CL were greater (P < 0.05) in LF group. In experiments 2 (unknown cyclic status) and 4 (noncycling), ovulations were synchronized, and beef cows received placebo or 150 mg of long-acting P4 on Day 4 after timed-artificial insemination. In experiment 2, pregnancy/AI (P/AI) did not differ (P > 0.1) between P4-treated (53.2%; 209/393) and control cows (56.2%; 219/390), but P/AI was greater in cows with a CL < 0.9 cm2 on Day 4 that were P4-treated (57.9%, 22/38) versus placebo-treated (40.4%, 21/52; P < 0.05). In Experiment 4, P/AI was greater (P < 0.05) in P4-treated cows (55.6%, 105/189 vs. 46.0%, 86/187). In Experiment 3, cyclic?suckled beef cows were treated as described in Experiment 1 to generate animals with small (SF; n ¼ 111) or large POF (LF; n ¼ 109), and subdivided to receive placebo or P4 on Day 4. POF size, ovulation rate, CL area, and P/AI were greater (P < 0.007) in the LF group. Pregnancy/AI in ovulated cows were lower (P ¼ 0.05) in the SF/control group (41.5%, 17/41) compared to LF/control group (62%, 31/50) and were similar for the SF/P4 group (55.6%, 25/45) and LF/P4 group (57%, 28/49) compared to others. In summary, smaller and less vascularized POF results in less functional CL and reduces ovulatory rate and P/AI in cyclic beef cows; the long-acting P4 injection on Day 4 after timed-artificial insemination may attenuate the negative effects of small POF/CL; and postovulatory P4 supplementation improved fertility in anestrous beef cattle.
Thesagro: | Gado de corte; Ovulacao; Reproducao animal.
Thesaurus Nal: | Animal reproduction; beef; Beef cows; cows; Ovulation.
Categoria do assunto: | L Ciência Animal e Produtos de Origem Animal
Registro original: | Embrapa Pantanal (CPAP)
Exemplares: | CPAP - (59772-1) - UPC - AP - PP - SP18243 -  - 18243 - DIS