1110 GnRH increased pregnancy risk in suckled beef cows that did not display estrus when subjected to a split-time artificial insemination program

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 532-532
Author(s):  
S. L. Hill ◽  
D. M. Grieger ◽  
K. C. Olson ◽  
J. R. Jaeger ◽  
C. R. Dahlen ◽  
...  
2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 533-534
Author(s):  
B. E. Bishop ◽  
J. M. Abel ◽  
J. M. Thomas ◽  
M. F. Smith ◽  
S. E. Poock ◽  
...  

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 534-534
Author(s):  
J. M. Abel ◽  
B. E. Bishop ◽  
J. M. Thomas ◽  
M. R. Ellersieck ◽  
S. E. Poock ◽  
...  

2016 ◽  
Vol 94 (9) ◽  
pp. 3703-3710 ◽  
Author(s):  
S. L. Hill ◽  
D. M. Grieger ◽  
K. C. Olson ◽  
J. R. Jaeger ◽  
C. R. Dahlen ◽  
...  

Author(s):  
J. Stevenson ◽  
S. L. Hill ◽  
D. M. Grieger ◽  
K C Olson ◽  
J. R. Jaeger ◽  
...  

2002 ◽  
Vol 74 (3) ◽  
pp. 547-552 ◽  
Author(s):  
D. Cavestany ◽  
N. Negrin ◽  
R. Negrin ◽  
J. F. Groth

AbstractThe objective was to evaluate different oestrous synchronization schemes in beef cattle under range conditions. In experiment 1, 202 heifers averaging 26 months of age were assigned randomly to three treatments: (a) GnRH-PG. (no. = 44) day 0 (D0): injection of GnRH; D7: injection of PGF2α; D0 to D25 oestrous detection (OD) and artificial insemination (AI); (b) OD-PG. (no. = 45) D0 to D4; OD + AI; D5: injection of PGF2α; D5 to D25 OD + AI; and (c)Ovsynch. (no. = 113) D0: injection of GnRH; D7: injection of PGF2α; D9: injection of GnRH and 16 h later AI at fixed time. In experiment 2, 318 non-suckling cows were assigned randomly to three treatments: (a) GnRH-PG. (no. = 106) D0: injection of GnRH; D7: injection of PGF2α; D0 to D25 OD + AI; (b) GnRH-MAP-PG. (no. = 106) D0: injection of a GnRH analogue and insertion of an intravaginal sponge impregnated with 250 mg of medroxyprogesterone acetate; D7: injection of PGF2α and sponge withdrawal; D0 to D25 OD + AI; (c) controls. (no. = 106) OD and AI. The experimental period lasted 25 days and, with exception of the Ovsynch treatment, oestrous detection was carried out twice a day (a.m./p.m.) and inseminations performed 12 h later. The pregnancy rates assessed by ultrasonography 30 days after AI were: experiment 1: (a) 30·0%; (b) 28·6% and (c) 62·3% (P < 0·05); experiment 2: (a) 60·2%; (b) 57·8% and (c) 45·5% (P < 0·05). It is concluded that in heifers and non-suckling cows, oestrous synchronization treatments result in higher pregnancy rates. In non-suckling cows, the addition of a progestagen did not improve the response.


Author(s):  
Emmalee J Northrop-Albrecht ◽  
Jerica J J Rich ◽  
Robert A Cushman ◽  
Runan Yao ◽  
Xijin Ge ◽  
...  

Abstract Embryo survival and pregnancy success is increased among animals that exhibit estrus prior to fixed time artificial insemination (AI), but there are no differences in conceptus survival to d16. The objective of this study was to determine effects of preovulatory estradiol on uterine transcriptomes, select trophectoderm transcripts, and uterine luminal fluid (ULF) proteins. Beef cows/heifers were synchronized, artificially inseminated (d0), and grouped into either high (highE2) or low (lowE2) preovulatory estradiol. Uteri were flushed (d16); conceptuses and endometrial biopsies (n = 29) were collected. RNA sequencing was performed on endometrium. Real-Time PCR (RT-PCR) was performed on trophectoderm (TE; n = 21) RNA to measure relative abundance of IFNT, PTGS2, TM4SF1, C3, FGFR2, and GAPDH. Uterine fluid was analyzed using 2D LC–MS/MS based iTRAQ method. RT-PCR data were analyzed using the MIXED procedure in SAS. There were no differences in mRNA abundances in TE, but there were 432 differentially expressed genes (DEGs) (253 downregulated, 179 upregulated) in highE2/conceptus versus lowE2/conceptus groups. There were also 48 differentially expressed proteins (DEPs; 19 upregulated, 29 downregulated), 6 of these were differentially expressed (FDR &lt; 0.10) at the mRNA level. Similar pathways for mRNA and proteins included: calcium signaling, protein kinase A signaling, and corticotropin releasing hormone (CRH) signaling. These differences in uterine function, may be preparing the conceptus for improved likelihood of survival after d16 among highE2 animals.


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