Autor(es):
Costa, Natália Paulozzi [UNESP] ; Gonella-Diaza, Angela ; Pugliesi, Guilherme ; Cordeiro Maldonado, Mariângela Bueno [UNESP] ; Scollari, Saara Carollina ; Mello, Barbara Piffero ; Feltrin, Isabella [UNESP] ; Girotto, Renato ; Castilho, Caliê ; Bertan Membrive, Claudia Maria [UNESP]
Data: 2020
Identificador Persistente: http://hdl.handle.net/11449/201182
Origem: Oasisbr
Assunto(s): Bos indicus; bST; Corpus luteum; Endometrium; Fertility; Bos indicus; Bos indicus; bST; bST; Corpus luteum; Corpus luteum; Endometrium; Endometrium; Fertility; Fertility
Descrição
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação para o Desenvolvimento da UNESP (FUNDUNESP)
Universidade Estadual Paulista
The aim of this research was to evaluate the effect of recombinant bovine somatotropin (bST) on pregnancy per artificial insemination (P/AI), cellular composition of the corpus luteum (CL) and endometrial gland morphometry. In Experiment 1, Nelore cows (n = 587) received a fixed-time artificial insemination (FTAI) protocol and, at insemination, received 0, 250 or 500 mg of bST subcutaneously (SC). In Experiment 2, Nelore cows (n = 243) received 0 or 500 mg of bST, SC, on D7 (D0 = day of FTAI). Blood samples were collected on D7 and D16 to measure progesterone (P4) concentrations. In Experiments 1 and 2, pregnancy diagnosis was performed 30 days after FTAI. In Experiment 3, Nelore heifers (n = 20) received a FTAI protocol, but were not inseminated, and on D0 (ovulation day), they received 0 (bST 0; n = 9) or 500 mg of bST (bST 500; n = 11), SC. The heifers were slaughtered on D15 (D0 = ovulation day), at which time the CL was evaluated for diameter, weight, a percentage of large (LLC) and small (SLC) luteal cells, and the concentration of progesterone in plasma measured. The number, perimeter and area of superficial and deep endometrial glands were evaluated. There was no difference in P/AI when bST was applied on D0 and D7. In Experiment 1, P/AI did not differ among treatments, with 59.28% (115/194), 58.38% (115/197) and 65.82% (129/196) for the bST 0, 250 and 500 treatments, respectively. In Experiment 2, P/AI did not differ between treatments, with 57.3% (71/124) and 60.5% (62/119) for the bST 0 and 500 treatments, respectively. Plasma progesterone concentrations on D16 was greater in the bST 500 (11.63 ± 0.84 ng/mL) than bST 0 (9.83 ± 0.88 ng/mL). In Experiment 3, there was no difference in ovarian diameter and weight, CL diameter, percentage of SLC, P4 concentrations and endometrial gland morphology. Heifers in the bST 500 treatment had heavier CL (3.11 ± 0.32 vs. 2.25 ± 0.20 g); however, the bST 0 treatment heifers had a greater percentage of LLC than did the bST 500 treatment (13.72 ± 1.16% vs. 8.60 ± 1.52). It was concluded that the doses of bST used in this study do not increase P/AI; however, they do cause changes in P4 concentration and the cellular composition of the CL.
São Paulo State University - UNESP
University of Florida North Florida Research & Education Center Institute of Food and Agricultural Sciences
University of São Paulo
RG Advanced Genetics
University of São Paulo West
São Paulo State University - UNESP
